Thursday, February 27, 2020

False Identity or Misrepresentation in Social Media Assignment

False Identity or Misrepresentation in Social Media - Assignment Example Criminals use this opportunity to get access to others’ profiles by sending friend requests. Once approved, they get access to the victim’s personal data, photographs and albums which they might forward to adult sites, or this may lead to telephonic conversations and meetings, and nobody knows about the consequences. The criminal can also adopt identity of real people by using their hacked photographs and information, for the purpose of attracting friends. This topic holds a strong place among ethical issues in e-marketing. Internet savvy persons are getting more and more informed about false e-marketing or fake e-business advertisements. False identity helps the criminal in preplanned attacks against payment systems like pensions and medical insurance. E-marketing ethics require that in order to carry out effective e-marketing, the e-marketer must base the business on honest grounds. If he is honest in displaying his identity, consumers will automatically come to him because e-consumers always do business with the names they can trust. Similarly, it is unethical to adopt the identity of another successful organization as doing so tends to bring harm to the reputation of the owner of the cloned identity. Here is an example when the issue was handled ethically. According to PR Log (2009), a Press Release, twenty fake identity factories had been sealed which were being operated by criminals who produced cloned driving licenses and utility bills. The Metropolitan Police was able to track down these factories in an Operation, arrested the criminals and closed the factories. If such criminals keep on getting caught, then this would be a good lesson for those who think of crossing the ethical boundaries in interacting with social media and in carrying out e-marketing. Let’s discuss an example when this issue was not handled ethically. Johnson (2010) revealed in her article that according

Monday, February 10, 2020

Economic Cycle Research Paper Example | Topics and Well Written Essays - 1250 words

Economic Cycle - Research Paper Example These fluctuations are what are referred as economic or business cycles and distinguish recessions from expansions. Recessions or depressions â€Å"are period of economic decline, expansion/boom of economic prosperity, and inclusive of the ebbs and flows of economic activity make up economic/business cycle† (Romer, â€Å"The Business Cycle†). Today, most economic experts tend to determine these cycles by identifying the turning and on-trend points through different methodologies like use of the level of output or level of output gap. Though economic cycles can be traced before WWII upon various economic crisis, much of the concept today adopted the classical work of Burns and Mitchell, who characterized them â€Å"as fluctuations of output around the growth path that occur with a frequency of three to five years† (Araujo 6). With a complete set of data for the period and greater understanding of the existing economic indicators, one could determine the amplitude and duration of the economic cycle, and the co-movement of economic activities involved when comparing several economies. Experts use economic indicators to forecast and explain the causes of the economic cycles. Considering there are recurrent seasons of booms and depressions, different events, policies and decisions applied or adopted by the involved parties must have occurred to either stimulate a shock or recovery after recessions. An economy is said to be at full employment when it achieves a level of production, when all the inputs to the production process are actively used, inflation remains constant, and output is within the normal range (Romer, â€Å"The Business Cycle†). Changes in factors that influence deviation from this normal production could trigger inflation and push the economy either beyond or below the full employment range to cause cycles in an economic performance. Below are the influencing factors; monetary policy, public spending, prising,

Friday, January 31, 2020

Php Login Script with Remember Me Feature Essay Example for Free

Php Login Script with Remember Me Feature Essay I wanted to include the popular Remember Me feature seen on a lot of websites that basically keeps users logged into the website, even after theyve closed the browser so that the next time they come, they wont have to login again manually. I found this tutorial Creating a PHP Login Script to be very helpful in writing this script, in fact, a lot of the code presented here is very similar to the code presented in that tutorial. The differences are seen with the new Remember Me feature, the use of cookies in addition to sessions, and with slight modifications in the design. Goals The ultimate goal is to create a PHP login script with the capability of remembering logged-in users. I also hope this tutorial will serve as a way to introduce people to user sessions and cookies in PHP. Notes Although this tutorial uses a MySQL database for storing user information, it has been written so that the data accessing code is separated from the main code through specific functions, so it would be easy to instead use a flat file database system, simply by changing the code in those specific functions, without messing with the rest. This tutorial uses the latest and greatest of PHP 4, which means super globals are used, such as $_POST, $_SESSION, etc.. This tutorial will aim to teach you about sessions and cookies through example, however if you need to know more information, go to the official website . Database For those of you planning on using a flat file system, you can skip this section. For the rest of us, we want to create a MySQL database table that holds user information, here it is: CREATE TABLE users ( sername varchar(30), password varchar(32)); Of course this table can be modified according to your needs, however the password field must not be less than 32 because it has to store the md5 encrypted versions of passwords which are 32 bytes. database. php This file will contain the code that connects you to your MySQL database and the functions that access user information, you need to modify this to show your MySQL username, password and database. Allow Users to Sign-Up Before we can login users, we need users. Here we will focus on the code that allows users to sign-up, registering their username and password. register. php Registered! Thank you , your information has been added to the database, you may now log in. Registration Failed Were sorry, but an error has occurred and your registration for the username , could not be completed. Please try again at a later time. Registration Page Registration Page Register Login Username: Password: Remember me next time Join

Wednesday, January 22, 2020

The Symbolic Use of Nature in Hawthornes The Scarlet Letter Essay

The Symbolic Use of Nature in The Scarlet Letter      Ã‚     In Nathaniel Hawthorne's classic The Scarlet Letter, nature plays a very important and symbolic role.   Hawthorne uses nature to convey the mood of a scene, to describe characters, and to link the natural elements with human nature.   Many of the passages that have to do with nature accomplish more than one of these ideas.   All throughout the book, nature is incorporated into the story line. The deep symbolism conveyed by certain aspects of nature helps the reader gain a deeper understanding of the plight and inner emotions of the characters in the novel.      Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Hawthorne's moods or prevailing feelings during certain scenes are revealed to the reader through nature.   For example, one of the first scenes in the book demonstrates this unique writing talent that Hawthorne uses to enrich his writing.   He describes Hester Prynne and her child being released from the local prison into the light of day;    She bore in her arms a child, a baby of some three months old, who winked and turned aside its little face from the too vivid light of day; because its experience, heretofore, had brought it acquainted only with the gray twilight of a dungeon, or other darksome apartment of the prison (49).         The sunlight gives the reader a feeling of exposure and scrutiny.   This feeling is later reveled to the reader by Hawthorne,    Her prison-door was thrown open, and she came forth into the sunshine, which, falling on all alike, seemed, to her sick and morbid heart, as if meant for no other purpose than to revel the scarlet letter on her breast (71).       It is also gives the feeling of a release into a harsh environment, which Hest... ...escarletletter/fullsumm.html. February 15, 2002.    Brown, Bryan D. "Reexamining Nathaniel Hawthorne's The Scarlet Letter. http://www.usinternet.com/users/bdbournellonie.htm. March 1, 2002.    "Chuck III College Resources". http://www.chuckiii.com/reports/book_reports/scarlet_letter.shtml. March 1, 2002.    Clendenning, John. "Nathaniel Hawthorne." The World Book Encyclopedia. 2000 ed.    Griswold, Rufus Wilmot. "The Scarlet Letter." The Library of Literary Criticism of English and American Authors. Ed. Charles Wells Moulton. Gloucester, Massachusetts: Peter Smith Publishing, 1959. 341-371.    Hawthorne, Nathaniel. The Scarlet Letter. New York: Penguin Books USA Inc., 1996.    Smiles, Samuel. "The Scarlet Letter." The Critical Temper. Ed. Martin Tucker. New York City: Frederick Ungar Publishing Company, 1962. 266.   

Tuesday, January 14, 2020

Ap Euro Calendar Dbq

Explain the reasons for the adoption of a new calendar in revolutionary France and analyze reactions to it in the period 1789 to 1806. The adoption of the revolutionary calendar to replace the Gregorian calendar took place on November 24, 1793 by the National Convention. This new calendar lasted until Napoleon I abolished it in 1806. The new calendar was a adopted in revolutionary France for many reasons including secular ideas and political reasons. There were also many reactions to the change of calendar between 1789 and 1806 such a criticism.There were many secular-slanted ideas that were adopted into the new calendar during revolutionary france. In 1789, the Cahier de doleances (report of grievances), from the Third Estate of Chateau-Thierry, said that they asked for the number of religious holidays be reduced because each of them enchains the activity of a great people, being of considerable detriment to the state and the numerous disadvantages of idleness. This shows that the n ew calendar was more secular because of the decrease in the amount of religious holidays (Document 1).The illustrations of newly named months also show that the new calendar shows more secular-slanted ideas. The new months are named for prosperity and things they are known for. For example, the month of Fructidor which is the month of harvest is between August 18 and September 16, which harvest time. This shows a more secular calendar because the months are associate France with French stuff, instead of the old months being named after religious people (Document 4).In a letter to the National Convention from a peasant from Etampes, it says that with nine long, hard days of labor, the simple citizens want small distractions on their day of rest. During the use of the new calendar in France, people went to church a lot less because with the new calendar they would only go every tenth day, instead of going on Sundays during the Gregorian calendar (Document 7). Government officials in t he French town of Steenwerck, Picardy, said that people spend less time in the temple celebrating the tenth day and revolutionary festivals as an affront to republicans.This shows that the new calendar was more secular because with the new calendar people began to go to church less (Document 10). The new calendar in revolutionary France, showed how France started to move towards a more secular world. A lot of people agreed with the adoption of the new calendar by revolutionary France for many reasons. Gilbert Romme, head of the calendar reform committee, believed that the church calendar was born among ignorant people. He said â€Å"Time opens a new book for history, and it must use a new pen to record the annals of a regenerated France. What Romme means by this is that since France is going through new times, they need to change the calendar to fit it (Document 2). In â€Å"Instruction Concerning the Era of the Republic and the Division of the Year† which was a decree of th e National Convention, it said that the new calendar will eliminate incoherence and inexactitude. This means that with the new calendar people will be more exact and orderly because of more work days. It also states that the new calendar will show the character of our revolution (Document 5). In the letter to the National Convention from the village of St.Quirin, it says how the people spend their day of rest. In the letter it says that they honor the memory of the generals who have become martyrs and they read aloud the republican accomplishments. The people of the village of Quirin supported the new calendar because they got the tenth day off (Document 6). Many people agreed with the change to the new calendar in revolutionary France because, they thought it was needed since france was going through new times, they also thought the more work days will make people work better, and because some people thought that the tenth day was great.Until the new calendar was abolished by Napol eon I in 1806, it received a lot of criticism. Pierre-Joseph Denis, a former Girondin imprisoned during the Terror and then recalled to the National Convention, wrote in Opinion on the Decades that the new calendar was an act of despotism forced on the people, and the festivals based on it were detestable. Denis is criticizing the new calendar because he thinks that it was unfair that the new calendar was forced upon them (Document 8).Francois-Sebastien Letourneux, Minister of Interior, criticized the new calendar because he thinks that the interval between days of rest is too long. Letourneux said that the artisan and farmer can not work nine days in a row (Document 9). In an article in Gazette de France, it talks about the return to the Gregorian calendar. It says that the new calendar was so weak that when it fell, it didn't even offer us an opportunity to exclaim about the fragility of human things.The article also says that it was sad that the names of the festivals were not no t devoted to the benefactors of humanity, but were devoted to the cabbages, the turnips, and the artichoke (Document 11). Abbe Sieyes wrote in response to the Committee of Public Instruction's proposal for a new calendar, that it is not needed. Sieyes believed that there was no reason to differentiate ourselves from everyone else (Document 3). Many people didn't agree with the idea of the new calendar, which was the reason it only lasted until 1806.The new calendar was adopted in France for many reasons including to have more work days and to get rid of some of the holidays. Some people agreed with the new calendar because they thought that it was needed since France was changing and others agreed with it because they thought that with more work days, people will be more exact and will get more work done. Some people criticized it because they thought that nine straight days of work a week was bad for the farmers and artisans and because the new calendar wasn't needed.

Monday, January 6, 2020

Organizational Behavior 4415 Managing in Virtual...

Organizational Behavior As the entire human race has crossed the threshold of twenty-first century, it has revolutionized numerous facets in the world of commerce. The progressions and developments have not only been witnessed in the economic, political, environmental and social sectors but the industrial segment has also come under its radical and deep impacts. This industrial boom as well as intensified globalization has resulted in universal trade that has emerged a need for the businesses to broaden and expand their functions to an international platform (Brunsson 2008). The means and approaches of communication have alleviated the cultural, social and political differences amongst the populations not only on national level but also on a universal platform. In this regard, one cannot ignore the reality that the technological advancements in business community has given rise to the fierce and intense competition to the businesses and organizations that produced the enterprises to focus on amplified productivity in order to live to the expectations and demands of the consumers. Indeed, the trends of the working conditions of the marketplace in the recent years have also depicted that challenges are being encountered by the companies in order to stay competitive in the market as well as generate profits for which the need of efficient and effectual working had become a fundamental necessity (Brunsson 2008). A corporation is made up of numerous departments that

Sunday, December 29, 2019

Energy crisis - Free Essay Example

Sample details Pages: 32 Words: 9476 Downloads: 6 Date added: 2017/06/26 Category Statistics Essay Did you like this example? ntroducton vr nc th nrgy cr, whn dgtl control (thn clld MC for nrgy mngmnt nd control ytm) wr uncrmonouly uhrd nto wdprd u for HVC control, th ndutry h trd to mk thm look nd ct lk th pnumtc control thy hv uprdd. Only occonlly r om of th profoundly xpndd opportunt vlbl wth dgtl control ppld ffctvly. Furthrmor, trm lk rt chdul nd drct ctng, rlvnt only to pnumtc ytm, r tll commonly mployd n wht now th dgtl control r. Don’t waste time! Our writers will create an original "Energy crisis" essay for you Create order Whl th proc of trnton to dgtl control tchnolog tolrt th mxd bg, multtud of nw dmnd r rqurng our ndutry to mov hd nd rlz th full potntl of dgtl control tchnolog. Buldng occupnt r dmndng mor comfortbl nd hghr qulty nvronmnt. Buldng ownr contnu to pr for grtr conom n contructon, oprton, nd mntnnc. Fnlly, vrty of prur r upon u to provd mor prc control nd documntton tht tndrd for tmprtur, vntlton, nd ndoor r qulty r bng mt. n th rtcl, wll dcu how DDC tchnolog prmt nw flxblty n th trdtonl rul concrnng th nd for lnr gnl nd rpon wth nput nd output dvc. Whn proprly ppld, th nw flxblty cn rduc th cot of DDC tchnolog. Nxt month, wll how how, by combnng th fundmntl wth mrgng ntr mnufcturr control ntgrton, dgnr cn chv nw horzon n prformnc nd nrgy ffcncy. HVC Control ytm HVC control ytm computrzd ytm for clmt control n buldng. HVC tnd for humdty, vntlton , r-condtonng. Oftn, th ntgrt fr, curty, nd lghtng control nto on ytm. Th ytm typclly u on or mor cntrl controllr to commnd nd montor th rmot trmnl unt controllr, nd thy communct wth on or mor pronl computr tht r ud th oprtor ntrfc. Th control ytm r typclly ud on lrg commrcl nd ndutrl buldng to llow cntrl control of mny HVC unt round th buldng(). Th ltt ytm u th buldng thrnt for communcton btwn cntrl controllr, nd llow oprtor cc from wb browr. Drct Dgtl Control Cntrl controllr nd mot trmnl unt controllr r progrmmbl, mnng th drct dgtl control progrm cod my b cutomzd for th ntndd u. Th progrm ftur nclud tm chdul, tpont, controllr, logc, tmr, trnd log, nd lrm. Th unt controllr typclly hv nlog nd dgtl nput, tht llow murmnt of th vrbl (tmprtur, humdty, or prur) nd nlog nd dgtl output for control of th mdum (hot/cold wtr nd/or tm). Dgtl nput r typclly (dry) contct from control dvc, nd nlog nput r typclly voltg or currnt murmnt from vrbl (tmprtur, humdty, vlocty, or prur) nng dvc. Dgtl output r typclly rly contct ud to trt nd top qupmnt, nd nlog output r typclly voltg or currnt gnl to control th movmnt of th mdum (r/wtr/tm) control dvc.(Vlv/dmpr/motor pd) t w only nturl tht th frt HVC controllr would b pnumtc, th ngnr undrtood flud control. Thu mchncl ngnr could u thr xprnc wth th proprt of tm nd r to control th flow of htd or coold r. To th dy, thr pnumtc HVC qupmnt n oprton, whch cn b cntury old, n om buldng, uch chool nd offc. ftr th control of r flow nd tmprtur w tndrdzd, th u of lctromchncl rly n lddr logc, to wtch dmpr bcm tndrdzd. vntully, th rly bcm lctronc wtch, trntor vntully could hndl grtr currnt lod. By 1985, pnumtc control could no longr compt wth th nw tchnology. By th yr 2000, computrzd controllr wr common. Tody, om of th controllr cn vn b ccd by wb browr, whch nd no longr b n th m buldng th HVC qupmnt. Th llow om conom of cl, ngl oprton cntr cn ly montor thound of buldng. Why Lnr Dvc? Whn pnumtc control domntd our ndutry, buldng ownr pd hgh prc for modult n g l o o p p r f o r m n c n d tblty. On of th prc pd w th rqurmnt tht nput nd output dvc b lnr wth rpct to th ytm vrbl thy nd or controlld. Th nd for lnr rpon w ntl to mtch th lmtd control cpblt of pnumtc controllr. numbr of rul nd convnton wr tblhd wthn our ndutry tht md chvng th lnr rpon rqurmnt r. mong th wr th dvlopmnt of th qul prcntg vlv, whch ncludd th mngly bckwrd rul of thumb tht clld for zng control vlv mllr thn th pp z. mlrly, mchncl nng dvc wr contructd to provd lnr chng n control r prur ovr thr ntr nng rng. Whl th convnton nd rul of thumb rvd th dy of pnumtc, thy now nd to b rthought. Rqurng wht cll xtrnl lnrzton n dgtl control dgn dd cot n two wy. Lnr dvc r oftn mor xpnv thn nonlnr dvc tht my offr mprovd lvl of prformnc n DDC pplcton. Furthr, lnr output convnton, uch dgnng hgh prur drop through vlv or dmpr, crry ubtntl contnuou oprtng nrgy pnlty. By dvlopng nw rul nd convnton, th knowldgbl dgnr cn produc dgn tht hv lowr frt nd oprtng cot nd my oprt mor rlbly wll. Lnr Dvc n th DDC r Th nd for lnr rpon n modultng control loop h not bn lmntd by th ntroducton of dgtl control. Whl dgtl control offr mprovd modultng control cpblt, ncludng proportonl/ntgrl/drvtv (PD) controllr, th control loop contnu to b bd on th prncpl of lnr rpon, t lt ovr crtn rng. Howvr, n mot typcl pplcton, dgtl control cn ly ntrnlly lnrz both nput gnl nd output control functon. ntrnl Lnrzton of nput On wy to rduc th cot of om DDC confgurton to prmt nonlnr nput dvc nd u th DDC ytm for clng to chv th corrct rdng ovr th rng rqurd for th pplcton. contnu to DDC pcfcton tht lmt th lcton of nput dvc to tho tht provd lnr gnl to th DDC ytm ovr wd rng of vlu. xcpt n pcl c, th n unncry rqurmnt tht dd cot nd my cu othr problm. Condr tmprtur nor. Fg. 1 how rtnc curv for n nxpnv thrmtor typ tmprtur nor tht my b mployd for room tmprtur nng. Thrmtor r xcllnt choc for HVC pplcton. Thy r nxpnv, hv xcllnt ccurcy nd vry low hytr, nd rpond quckly to tmprtur chng. Furthrmor, t tmprtur normlly nvolvd n HVC pplcton, thrmtor hv xcllnt long-trm tblty (om cr hould b tkn n choong thrmtor whn tmprtur my r bov 240 F). Fnlly, bcu thrmtor r typclly hgh rtnc (10,000 ohm typcl), thy r not ffctd by vrton n wrng dtnc. Howvr, om dgnr contnu to xclud thrmtor bcu th nput gnl not lnr wth tmprtur ovr wd tmprtur rng. ntd, low mpdnc RTD typ nor r oftn pcfd. Th typ of nor typclly rqur n lctrc crcut t th nor tht lnrz nd trnmt th gnl n wy tht t wll not b ffctd by wrng rtnc (uully currnt loop gnl ud). mployng low rtnc RTD nor wth ddtonl lctronc prnt numbr of potntl problm n DDC pplcton. Frt th mttr of ccurcy. Whl th RTD nor thmlv provd xcllnt ccurcy, t not uncommon to fnd nd-tond ccurc ( u nd-to-nd th compron of th vlu rd by prcon thrmomtr t th dvc comprd wth th ctul rdng t th DDC ytm oprtor trmnl) out of tolrnc. Clbrton of th currnt loop nput my b mor dffcult thn tht of mpl rtnc typ thrmtor. Othr potntl problm wth RTD rng from th ddtonl lctronc (uully loctd t th dvc) tht my complct rlblty u ll th wy to how th nor curv 2 Nonlnr nor rtnc curv. Th nor prformnc curv mooth curv ovr th nor oprtng prur. Th DDC lnrzd curv r of trght ln tht cloly pproxmt th nor prformnc nor nd lctronc r confgurd, whch on occon h bn found to ffct dvrly th nor gnl. Tbl functon tht r now rdly vlbl wth DDC product cn b mployd to cl thrmtor nd othr nonlnr dvc ovr wd rng of vlu. Fg. 2 how how DDC ytm cn lnrz contnuou, nonlnr nor nput curv wth tbl functon. numbr of trght ln curv r tblhd n th tbl functon to pproxmt cloly th nonlnr functon of th dvc. long mpl, nxpnv dvc cn mt th rptblty, hytr, nd tblty rqurmnt for n HVC pplcton, uch dvc hould not b rjctd bcu thr gnl r not lnr. Rqurmnt of Lnr Output Onc t undrtood tht nput dvc nd not b lnr, t not grt lp to rcognz tht th rpon from output dvc controlld by nlog output mlrly nd not b lnr. Howvr, th u hr r mor complx nd mor ngrnd n th rul of thumb tht ngnr frquntly pply utomtclly, o om ndpth dcuon rqurd. Bcu of th pnumtc bckground, vlv dgn mnul commonly tr th nd to lct col/vlv combnton for whch qul ncrmnt n vlv poton wll ffct qul ncrmnt n ht trnfr of typcl htng or coolng col throughout th trok of th vlv ctutor. Fg. 3 how how trdtonl dgn prctc k to lnrz th ovrll prformnc of vlv nd coolng col. Crfully lctng col nd vlv combnton cn provd nrly lnr prformnc ovr th ntr rng of lod poblt. uch lcton don bcu t umd tht th vlv wll b oprtd by controllr wth fxd proportonl gn. Though th dgn prncpl tll wdly mployd, t no longr pplcbl n mny modrn HVC pplcton. n VV coolng col pplcton, th vrton of r flow nd r/chlld wtr tmprtur chrctrtc ct to chng dynmclly th ht trnfr chrctrtc of th vlv/col rrngmnt th prmtr chng. Th mk t vry dffcult to lct vlv/col combnton tht wll b lnr through th vrty of condton tht my ccompny t oprton. Th hghr prformnc of DDC ytm prmt dgnr much grtr flxblty n th dgn of modultng control wthout tblhng ttc (nd thrfor unrltc) dgn crtr. Fg. 4 how vlv nd col combnton tht do not provd lnr rpon of vlv poton to col cpcty. Howvr, modrn DDC ytm prmt clng tbl to b ppld to nlog output wll th nput. Output clng prmt n nhrntly nonlnr dvc combnton to rpond n lnr fhon to gnl from th DDC ytm. n th xmpl, th vlv nd col combnton provd bout 70 prcnt of th dgn coolng cpcty t bout 20 prcnt vlv trvl. Th DDC output to th vlv cn b djutd wth th clng tbl to poton th vlv t 20 prcnt trvl t 70 prcnt output gnl from th DDC ytm. Th clng fctor llow tndrd PD control to oprt th vlv ffctvly bcu of oftwr lnrzton of th vlv/col combnton. Howvr, th chlld wtr flow nd ht trnfr prformnc umd for Fg. 4 vld only for contnt lod-d flow nd nlt tmprtur nd for contnt chlld wtr upply tmprtur. Whthr nhrnt n th ytm dgn or for optmzton ron, rrly n rl HVC pplcton do th othr vrbl rmn contnt control loop oprt. prvouly dcud, th u of lnr output combnton h thrfor bn only wkly rolvd n th pt by ttmptng to lnrz componnt t on t of ytm condton. Obtnng good control ovr wd rng of ytm condton cn b rolvd fr mor compltly nd ffctvly wth th hghr prformnc cpblt of DDC ytm. Th proportonl, ntgrl, nd drvtv gn cn b td to lgorthm tht djut thr vlu th vrbl uch lod-d flow, tmprtur, nd chlld wtr tmprtur chng. vn mor mprv th mrgnc of lf-tunng controllr. Th controllr contnully r-tblh th vrou gn octd wth control loop to provd contnuouly prc control wthout huntng. Th bnft of lf-tunng r pclly mportnt bcu vrbl byond th mmdt control loop cn hv profound nd wdly vryng ffct on ch control loop. lf-tunng ftur r bcomng wdly vlbl wth DDC ytm nd r normouly ffctv n djutng control loop to contnu tbl oprton othr ytm vrbl chng. Controllblty prvouly dcud, lctng qupmnt for lnr rpon hould not b n ovrrdng condrton for dgnr n th r of dgtl control. Howvr, th do not mn dgnr cn b mprc n thr dgn or n th lcton of control loop componnt. Th u of controllblty on tht wll contnu to ply promnnt rol both n th dgn of ytm nd th lcton of ndvdul componnt. Controllblty rmn lrgly zng u. f vlv ovrzd for gvn condton uch tht th mllt ncrmnt pobl from th control loop wll ubtntlly ovrhoot th drd control condton, th loop h bcom uncontrollbl. Th problm tht typclly mrg durng prod of low lod. Fully undrtndng th u of controllblty nd pplyng DDC cpblt corrctly llow dgnr to olv uch problm nd t th m tm vtly mprov th ffcncy nd prformnc of th ytm. lctng control vlv wth lowr prur drop wll rduc th pumpng powr rqurd to mt th lod condton. Trdtonl prctc trongly condmn th d of mployng lrg vlv wth lowr prur drop bcu of th nonlnr rpon nd th lck of controllblty t low lod. Fg. 5 llutrt th dlmm. Th vlv/col combnton wth Vlv my b lctd ccordng to trdtonl dgn prctc bcu t ronbly controllbl t low lod. Th vrtcl x ntrcpt rprnt th mllt ncrmntl coolng trnfr pobl th vlv crckd opn. Not tht t mll-only bout 10 prcnt of th dgn mxmum coolng rt. Th col combnton wth Vlv B h much lowr prur drop bcu Vlv B lrgr z vlv. Whl vlv/col Combnton B would rqur l pumpng powr, th Y-x ntrcpt much hghr thn tht for Combnton . Trdtonl dgn crtr typclly dclr Vlv B unutbl for th pplcton bcu t uncontrollbl t lowr lod nd th vlv poton/ coolng cpcty rltonhp nonlnr. But whn t ntgrtd wth hgh-prformnc control ytm tht cn djut both th chlld wtr tmprtur nd th loop hd prur, wll lnrty nd controllblty of Combnton B rlly b problm? ytm Dynmc To how th quton cn b nwrd, condr th grph n Fg. 6 nd 7. Fg. 6 how th oprton curv for vlv/col Combnton B t numbr of dffrnt pproch (chlld wtr upply l r tmprtur lvng col) tmprtur condton. t clr tht ncrng th chlld wtr tmprtur rltv to th lvng r tmprtur mrkdly mprov th controllblty t low lod. mlrly, Fg. 7 llutrt tht th dcr n prur cro th vlv/col combnton lo mprov th controllblty t low lod. Dgnr cn u th rltonhp to rduc ubtntlly th problm of controllblty. t prod of unform low lod, th DDC ytm cn rduc th hd prur cro vlv nd ncr th chlld wtr tmprtur to mprov controllblty. f ll vlv on common chlld wtr loop xprnc mlr dcr n lod concurrntly, typcl n mny HVC pplcton, th prmtr djutmnt grt hlp n mprovng controllblty t low lod. t pprnt from th two fgur tht lrgr rngblty nd low lod controllblty r chvd by controllng th chlld wtr tmprtur for lod djutmnt. Rng th chlld wtr tmprtur provd bonu of chllr ffcncy ncr, but chlld wtr djutmnt rduc pumpng vng bcu hghr chlld wtr tmprtur ncr th wtr flow ncry to mt lod. ddtonlly, undr crtn crcumtnc dhumdfcton rqurmnt my lmt th prmbl chlld wtr djutmnt. xplotng th ntgrtd control cpblt of DDC ytm nd controllng chlld wtr tmprtur nd hydronc loop prur n coordnton wth th control vlv llow vlv/col Combnton B to prform vry wll n mny HVC pplcton. Nxt month w wll focu on th lvl of ntgrton rqurd to mk vlv/col Confgurton B oprt ffctvly. W wll dcu ntgrtng th oprton of th vrou qupmnt nvolvd n provdng comfort, pobl now through th ndutry mov to provd communcton brdg mong mnufcturr. By concntrtng on lctng th mot cotffctv nput/output dvc nd by utlzng th mrgng communcton pthwy btwn qupmnt from vrou upplr, w wll tht nw horzon of prformnc nd nrgy ffcncy cn b ttnd wth mpl nd conomcl control confgurton. Dgnr mut xplot th bnft of hghr prformng DDC ytm to dvlop n undrtndng of th fundmntl of ntrfcng hrdwr pont to DDC ytm. n o dong, mor n-dpth look nto totl ytm oprton mut b vlutd bfor oluton r lctd. mply followng trdtonl rul of thumb rgrdng lnr nput nd output dvc poor dgn prctc n th dgtl control r. DDC nd mll nd Mdum z Buldng Th control of htng, vntltng nd r-condtonng (HVC) ytm chngng rult of pplyng drct dgtl control (DDC) tchnqu to HVC control. Th rport outln th mn ftur of DDC comprd wth convntonl pnumtc control nd how tht, for mll-to-mdum-z buldng, th DDC ytm cn py for tlf wthn two yr, ftr whch t ffct nt vng ovr pnumtc ytm. Compron btwn Pnumtc Control nd DDC Drct dgtl control of HVC ytm th drct montorng of vry ytm nput (tmprtur, flow, prur) nd drct control of vry ytm output (poton, onlff) from cntrl controllr whch ngl computr or combnton of computr. DDC mpl concpt, but t gnfcnc not obvou untl t comprd wth trdtonl form of HVC control. Trdtonlly, th control of HVC ytm w bd on ndpndnt pnumtc controllr, whch ud comprd r t o oprt th dmpr nd vlv ctutor t o control pc condton uch tmprtur, humdty nd frh-r crculton. On buldng would hv vrl uch ytm, whch wr controlld ndpndntly. For xmpl, n r-hndlng ytm compod of two fn, thr dmpr nd thr vlv (Fgur 1) would b controlld by locl pnumtc controllr whch oprtd ndpndnt unt. ch controllr hd mpl tk: to mntn contnt t pont (for xmpl, upply r tmprtur) by montorng nd controllng vry l m t d numbr of vrbl connctd to t by mn of comprd r ln who prur rprntd th vlu of th vrbl. Th control w djutd mchnclly by tchncn n th fld, nd, clbrton of th pnumtc componnt w rrly crrd out, th ytm oftn dd not control th buldng ffcntly. Bcu th pnumtc controllr wr purly lctromchncl dvc, thr ophtcton nd ccurcy of control wr xtrmly lmtd. ltr vrnt (of pnumtc control) lo mployd pnumtc cntrl, but w t h th ddton of computr ytm. Th comput ytm montord om ddtonl pont (for xmpl, pc tmprtur) nd thr clcultd nw t pont for ch pnumtc controllr or llowd n oprtor t computr trmnl to trnmt mnul t pont to th pnumtc controllr. lthough th nwr vrnt dd th buldng mngr by provdng mor nformton bout buldng condton nd prformnc, ovrll ffctv control of th buldng w tll compromd by th locl pnumtc controllr. ch controlld pont w tll oprtd by pnumtc controllr wth vry lmtd ophtcton nd vrtully no flxblty. Th lmtton bcm mor mportnt wy to mng nrgy bcm mor ophtctd, om WC ytm, uch vrbl r volum (VV) ytm, rqurd n ccurcy of control not ttnbl n mot c by pnumtc controllr. rult, buldng nrgy mngr wr frutrtd by thr nblty to mprov th control trtg wthout rbuldng th pnumtc control ytm for ch chng. DDC h olvd both problm;. ntd of ndpndnt locl pnumtc controllr, DDC u control or montorng pont, ch connctd to computr (or ntrconnctd computr) whch rd th vlu of ch nput nd trnmt commnd to ch output (Fgur 2). Th control trtg r mplmntd by computr progrm, whch cn b chngd by th oprtor t wll. lo, ch trtgy h vlbl to t th vlu of vry ytm nput ntd of vry l m t d locl t. n hort, undr th DDC concpt, th ntr buldng oprt on ntgrtd ytm rthr thn ndpndnt rrrll ytm. Four mn rult ccru: Control cn b mpl or ophtctd drd, nd cn b chngd ly; Th ytm mor rlbl bcu fwr lctromchncl componnt r ndd; Control mor ccurt bcu of th nhrnt grtr ccurcy of DDC lctronc componnt; nd nrgy vd bcu n ovrll trtgy lmnt nrgy wt rultng from multnou htng nd coolng, whch uully occur n pnumtc ytm. Th blty of DDC to ccommodt vrtully ny control trtgy h hd drmtc mpct on mchncl dgn. om nw mchncl ytm cn oprt n mny dffrnt mod, dpndng on xtrnl condton, pc tmprtur, on, condton of torg tnk, nd utlty-prcng tructur. DDC llow uch ytm to b oprtd contnuouly n thr optmum mod, tndrd whch mply cnnot b ttnd by ordnry pnumtc ytm or vn pnumtc ytm wth computr montorng. Conquntly, mchncl dgnr r now fr to d g n th bt nrgy ytm for prtculr buldng wth th urnc tht whtvr control trtg thy pcfy cn b crrd out. ch loop t th rmot procor cn ctvt tlf ndpndnt of th othr; howvr, th mot ffcnt u of nrgy chvd by controllng ll th loop through th cntrl procor. chdulng r-condtonng nd htng lod nd lctvly droppng lctrcl lod f th totl buldng powr pproch th dmnd lmt r two common nrgy optmzton ftur vlbl. Othr ftur, uch optml top/trt, whch clcult th optmum trtng nd toppng tm of htng/coolng unt to prpr pc for occupncy wthout wtng nrgy, r lo ud prt of n ovr-ll trtgy. Mot of th optmzton routn do not rqur ny ddtonl hrdwr nc thy r mplmntd by mply ddng progrm tht n xtng nput nd chng th trtgy for controllng xtng output ctutor. Th buldng ownr or mngr who u DDC ffctvly nd fdbck to vlut h trtg for optmzng buldng prformnc. DDC mplf th proc bcu t contnully montor ch nput drctly nd h torg cpcty to kp fl of th htorcl dt thu obtnd. Th htorcl dt cn b plottd n color on TV crn or ummrzd nd prntd n rport formt for mngmnt rvw. Th mot dvncd DDC ytm (Fgur 3) nclud gnrlzd rport gnrtor whch cn produc n typ of rport t ny tm rthr thn lmt th ur to th rport nggd whn th ytm w procurd* Th ftur of DDC prtculrly mportnt nc th ownr powr to chng h nrgy trtgy gnrlly crt nd for nw rport on nrgy-ntv r dntfd by contnud u of th ytm. n ncllry bnft th blty of th DDG ytm to nclud fclt othr thn WC. Wth lttl ncr n cot, fctor uch control of curty nd lghtng cn b ddd to th ytm, thrby nblng grtr nrgy vng nd lmntng th nd to purch prt ytm for bdg rdng nd door-lock control. Thr no doubt tht DDC offr mor ffctv nrgy mngmnt thn convntonl control but, untl vry rcntly, t pplcton to HVC ntllton h bn lmtd to lrg buldng complx. Mny mll- nd mdum z buldng ntllton do not u DDC mnly bcu of t hgh cot. n th followng cton typcl mll buldng nlyzd nd DDC comprd wth pnumtc control on cot nd pybck b. mll Buldng ytm Th cot of n HVC control ntllton gnrlly rltd to th numbr of pont t o b montord or controlld, whr ch pont dfnd n nlog or dgtl nput (.g., tmprtur nor, fn ttu wtch) or nlog or dgtl output (.g. dmpr poton or pump on/off control. ch buldng ytm, uch r hndlng, domtc hot wtr, or chlld wtr, nclud crtn numbr of pont. rcnt tudy whch ncludd dtld nly of r of buldng HVC ytm, howd tht mll- to mdum-z buldng of bout 37,175 m2 (400,000 q. ft .) would contn bout 180 pont, of whch 35% would b nlog nput, 19% nlog output, 25% dgtl nput nd 21% dgtl output. lthough dffrnt buldng confgurton nd mchncl dgn would ffct th dtrbuton of pont typ, th totl numbr of pont for buldng of th z would uully b clo to 180. Dgnng DDC ytm Gvn th buldng lyout nd th numbr of pont n HVC qupmnt, th ngl grtt dgn trd-off tht btwn cntrlzton nd dtrbuton of computr powr. t th fully cntrlzd xtrm ngl cntrl computr control ll functon drctly nd ll pont r wrd to t. t th othr xtrm (fully dtrbutd), mllr cntrl computr connctd t o myrd of othr mll computr, ch of whch wrd to 10 to 20 nrby pont, n th cond ntnc th cntrl mchn prd vr th whol ytm nd control th pont through th ntrmdry of th rmot procor. ch rmot procor cn control ngl HVC ytm (.g. r-hndlng unt, chllr) ndpndntly. mdn pproch to mploy modrt numbr of rmot unt ch of whch wrd to 50 t o 120 pont. lthough ll th pproch utlz th bnft of DDC, th thr lvl of cntrlzton/dtrbuton nvolv thr fctor tht mut b wghd gnt on nothr. Th frt fctor th cot of computr hrdwr. Th fully-cntrlzd pproch mploy ngl procor, whch th lt xpnv nc t combn ll th computng powr n on plc w t h on nclour nd no duplcton of functon. Th fully-dtrbutd pproch rqur th hvt cptl cot for computr hrdwr. Th cond fctor lctrcl ntllton cot. Th fully dtrbutd rrngmnt yld th lowt ntllton cot bcu ch rmot procor cn b loctd vry clo to t pont nd thu wrng run r hort. Th fully-cntrlzd rrngmnt my b qut xpnv unl ll pont r n on mchncl room. Th mdn rrngmnt (Fgur 4) my b th mot conomcl ovr-ll bcu four rmot procor cn b ud, on n pnthou, on n om othr logcl locton uch bmnt mchncl room, nd othr on vrou floor of th buldng. Th thrd fctor rlblty. Th fully-cntrlzd chm mot ntv to flur nc flur of th ngl computr cu th ntr ytm to fl. lthough th ytm cn b md to fl fly, ytm flur nconvnnt. Th fully-dtrbutd chm lt ntv nc ny componnt computr cn fl whl tll lvng ll th othr runnng, but, prvouly mntond, th cot of th computng qupmnt hght. mdn pproch for mll buldng mk good n; comprom on ll fctor tblhd by dgnng ytm contng of cntrl computr nd four rmot unt. Cot nly: DDC vru Pnumtc Control Th ntlld cot of DDC ytm h trdtonlly bn hghr thn for pnumtc y tn, pclly n mll ntllton, whr th cot of th DDC control procor prd ovr fwr pont. Th cot of pnumtc ytm tnd to r lnrly wth th numbr of pont, lrg ytm rqur mor ndpndnt locl controllr, whr wth DDC cntrl procor rqurd vn f o r ytm wth vry fw pont. Howvr, th rpdly fllng cot of computng hrdwr h rodd th htorcl prc dffrnc btwn DDC nd pnumtc ntllton. For pcfc buldng of 37,175 m2 (400,000 q. ft.), th ntlld cot of pnumtc ytm bout 75% of th cot of DDC ytm lthough th ntl cot of DDC ytm hghr thn for pnumtc ytm, t cn b rcovrd n urprngly hort tm . t rltc to um tht DDC ytm wll yld 10X% nrgy vng ovr nd bov convntonl pnumtc control, du mply to t mor ccurt nd ophtctd control, nd t o t blty to provd th buldng ownr wth nformton bout buldng prformnc nd r whr nrgy hould b bttr controlld. Ftur uch lod hd nd flxbl chdulng lon wll produc lrg nrgy vng, nd th vng wll ncr th ownr bcom mor fmlr wth th oprton of th buldng. f w um yrly mntnnc cot of $12,000 nd $10,000 for th DDC nd pnumtc ytm rpctvly, nd n nrgy ug of 322 quvlnt kWh/m2/yr. (30 kWh/q.ft./yr.) t $0.0275 pr kWh for both ytm, t wll tk 1.4 yr mor for th DDC to py f o r tlf thn t wll for th pnumtc ytm whn ud n th buldng undr condrton. ftr tht tm th DDC ytm wll v mony comprd wth th pnumtc control. nothr mpl clculton how tht for thr-yr pybck th DDC nrgy vng nd b only 5.7%, n ly ttnbl fgur. Concluon Drct dgtl control now cot compttv w t h pnumtc control for WC control n mll- to mdum-z buldng. Gvn th othr dvntg of DDC, prtculrly t blty t o ccommodt chng to control trtgy nd to provd dtld rport of buldng prformnc, DDC hould bcom th domnnt tchnology for buldng n th z rng. ddtonl dvlopmnt ndd to lowr th ct furthr. n th xmpl prntd n th ppr, ntrumntton th hght n g l cot, lrgly bcu ll pcfd ntrumntton ndutrl grd. Th dvlopmnt of commrcl-grd nor nd ctutor, prtculrly ll-lctronc typ, whch would obvt th nd f o r n ntrumnt r upply, wll contrbut grtly to th ccptnc of DDC. cond r of dvlopmnt l n dvng computr progrm for th cntrl nd rmot computr. nrgy mngr dmnd mor ophtcton nd th lbor cot for cutom dvlopmnt r, comprhnv nd flxbl oftwr pckg wll domnt th DDC/HVC mrkt.