일본의 분뇨처리 개황

김동민,Kim, Dong-Min 한국상하수도협회 1977 水道 Vol.12 No.-

산지개발(山地開發)의 경제성

김동민,Kim, Dong-Min 한국토양비료학회 1979 한국토양비료학회지 Vol.11 No.4

A new Farmland Expansion and Development Promotion Law was enacted in 1975. This law authorizes the Government to undertake development within a declared "reclamation area", wherever the land owners are unable to do so. In order to give additional impetus to conversion of waste hilly land into productive farmland, these hilly land development projects were conducted as large scale scheme which include soil fertility improvements such as the application of lime and phosphate. Farmland Expansion and Development Promotion Corps has attempted to undertake annual farm surveys in order to obtain some information about hilly land agriculture and farming operations within the reclamation project areas since 1976. As survey data accumulates, more and more clear picture of hilly land farming come to appear and enable us to conduct in-depth study. Effects of such upland reclamation include converting of previously unproductive slopeland into cultivable farmland for lucrative and commercial farming or food production. Furthermore, idle or marginal resources such as farm labor, equipment and compost would be fully employed. Socio-economic effects would include increases in land value and attitude change of farmers. On the other hand the preservation of natural environments might be damaged to the some extend by the projects. As shown in Table 7, the average farm size increased from 3,156 pyeong($3.3m^2$) to 5,562 pyeong, a 76.2% increase. The proportion of small farms with less than I ha dropped from 59.8% to 34.4%, but that of the large farms over 2 ha rose from 13.1% to 32.0% (See Table 8). The survey results indicate that as the farming on reclaimed uplands become time-honored, the acreage devoted for food crop production decreases against the economic crop growing acreage (see Table 6). For example, in the case of uplands reclaimed in 1972, the ratio of food crop acreages decreased from 99.7% in 1972 to 62.5% in 1977, whereas that of economic crop acreages increased from 0.3% in 1972 to 37.5% in 1977. The government used to actively encourage the farmers to carry out food crop production in the reclaimed upland targting toward the realization of self-sufficiency in food grains. It is, however, apparent that the farmers did hardly take the government advises as far as their economic interest were concerned. Yield per 10a. of various crops from the reclaimed uplands by year were surveyed as seen in Table 12. On the average, barley production in the reclaimed areas achieved 83.3% of the average unit yield from the existing upland in its 5 th year. Soybean yields showed a modest increase from 64% in the first year to 95%, in the 5 th year. In contrast, economic crops such as red pepper, totacco and radish achieved their maximum target yields in 3 years from starting to cultivate on the reclaimed farms. In order to test the post economic viability, an economic analysis was performed for each of selected subprojects on the basis of the data obtained through survey. The average actual internal economic rate of return on upland reclamation investments was found to be 20.3% which exceeded other types of projects of land and water development such as tidal land reclamation, irrigation or paddy rearrangement. The actual IRRs of subcategories of upland reclamation projects varied from 17.9% to 21.4% depending upon the kinds of cropping system adopted in each reclaimed areas such as food, economic, fruit or forage crops. 농업(農業)의 기대성장(期待成長)과 현실성장을 비교(比較)하기 위하여 1953-77. 기간(期間)을 3단계(段階)로 구분하여 역사적접근법(歷史的接近法)을 시도(試圖)하였으며 농경지(農耕地)의 타목적전환과 전작물(田作物)의 수요(需要)를 전망(展望)하였다. 야산개발의 필요성(必要性)을 검토(檢討)하기 위하여는 농경지(農耕地)의 외연적확대가 가능(可能)한 가를 살펴보았으며 개간지(開墾地)의 작부유형(作付類型)을 분류(分類)하였다. 야산개발의 지역농업(地域農業)에 미친 효과로는 개간농가(開墾農家)의 경영규모확대와 경지규모별호수분포가 대농화경향(大農化傾向)을 보이는 것 같고 개간지(開墾地)의 지가가 기경지(旣耕地)보다 빠른 상승율(上昇率)을 보였다. 야산개발지의 생산성(生産性)은 6년차(年次)만 되면 기경지수준에 가깝게 되고 따라서 소득지수도 이와 유사(類似)한 경향(傾向)을 보이고 있다. 야산개발사업의 수익성은 다른 토지개발사업보다 높고 작목별(作目別)로 보면 식량작물(食糧作物)보다는 경제작물이 높고 단작(單作)보다는 이모작(二毛作)의 경우가 유리(有利)하게 나타났다.

전극용 Ag Paste의 Cellulose Acetate Propionate(CAP) 개질에 따른 태양전지 효율 향상

김동민,임종찬,김진현,차상호,이종찬,Kim, Dong Min,Lim, Jong Chan,Kim, Jin Hyun,Cha, Sang-Ho,Lee, Jong-Chan 한국재료학회 2018 한국재료학회지 Vol.28 No.4

We investigate the effect of the modification of cellulose acetate propionate as an organic vehicle for silver paste on solar cell efficiency. For the modification of cellulose acetate propionate, poly(ethylene glycol) is introduced to the hydroxyl groups of a cellulose acetate propionate backbone via esterification reaction. The chemical structure and composition of poly(ethylene glycol) functionalized cellulose acetate propionate is characterized by Attenuated total reflectance Fourier transform infrared, $^1H$ nuclear magnetic resonance, differential scanning calorimetry and thermogravimetric analysis. Due to the effect of structural change for poly(ethylene glycol) functionalized cellulose acetate propionate on the viscosity of silver paste, the solar cell efficiency increases from 18.524 % to 18.652 %. In addition, when ethylene carbonate, which has a structure similar to poly(ethylene glycol), is introduced to cellulose acetate propionate via ring opening polymerization, we find that the efficiency of the solar cell increases from 18.524 % to 18.622 %.

염색공업단지 공동폐수처리장을 설계할 때의 유의점

김동민,Kim, Dong-Min 환경보전협회 1984 환경정보 Vol.6 No.3

엽납석을 활용한 저열팽창 코디어라이트 세라믹스 합성

김동민,정숙인,이훈철,이상진,Kim, Dong-Min,Jung, Sook-In,Lee, Hun-Chul,Lee, Sang-Jin 한국재료학회 2015 한국재료학회지 Vol.25 No.7

A low thermal expansion ceramic, cordierite ($2MgO{\cdot}2Al_2O_3{\cdot}5SiO_2$), was synthesized using pyrophyllite. Pyrophyllite usually consists of $SiO_2$ and $Al_2O_3$, which are the main components of cordierite. $MgCO_3$ and $Al(OH)_3$ were added in various amounts to pyrophyllite and fired for synthesis and sintering. ${\alpha}$-cordierite crystallized from $1000^{\circ}C$ with mixing of 20 wt% $MgCO_3$ and 1.7 wt% $Al(OH)_3$, and un-reacted cristobalite was also detected with the cordierite. As the temperature was increased to $1400^{\circ}C$, the cordierite yield was gradually increased. Powder compacts of the synthesized cordierite were sintered between $1250^{\circ}C{\sim}1400^{\circ}C$; the sintered samples showed a low thermal expansion coefficient of $2.1{\times}10^{-6}/^{\circ}C$ and typical sintering behavior. It is anticipated that it will be possible to synthesize cordierite ceramics on a mass production scale using the mineral pyrophyllite.

사물인터넷을 활용한 지능형원격제어시스템 구현

김동민,Kim, Dong Min 한국정보통신학회 2020 한국정보통신학회논문지 Vol.24 No.4

원격제어서버와 작동기가 무선네트워크를 통해 연결되어 동작하는 원격제어시스템은 그 편의성이 큰 만큼 잠재된 위험성도 크다. 신뢰할 수 없는 무선 채널로 인해 제어명령이 유실될 수 있기 때문이다. 지능형원격제어시스템은 작동기에 제어명령을 유추할 수 있는 기능을 추가하여 제어명령을 수신하지 못하는 경우에도 동작하도록 해주는 시스템이다. 본 논문에서는 지능형원격제어시스템 테스트베드를 구현하여 원격제어시스템에서 발생할 수 있는 문제 상황들을 실험을 통해 확인하고 지능형원격제어시스템이 문제를 해결하는 것을 검증하였다. 지능형원격제어시스템은 일반적인 원격제어시스템이 높은 통신오버헤드를 감수해야 달성할 수 있는 성능을 더 적은 통신오버헤드만으로도 달성할 수 있음을 확인하였다. The remote control system, in which the remote control server and the actuator are connected and operated through a wireless network, has a great potential risk as well as its convenience. The control commands can be lost because of unreliable wireless channels. The intelligent remote control system is a system that adds a function to infer a control command to the actuator to operate even if the control command is not received. In this paper, we implemented an intelligent remote control system testbed and confirmed the problems that could occur in the remote control system through experiments and verified that the intelligent remote control system solves the problem. The intelligent remote control system can achieve the performance that can be achieved when general remote control system has high communication overhead with less communication overhead.

안전점검을 통해본 건축상의 문제점과 개선책

김동민,Kim, Dong-Min 한국화재보험협회 1973 防災와 保險 Vol.1 No.-

다결정 실리콘 박막 위에 P이온 샤워 도핑 후 열처리 방법에 따르는 도펀트 활성화 및 결함 회복에 관한 효과

김동민,노재상,이기용,Kim, Dong-Min,Ro, Jae-Sang,Lee, Ki-Yong 한국전기화학회 2005 한국전기화학회지 Vol.8 No.1

Ion-Shower-Doping장비 및 $PH_/3M_2$혼합 가스를 사용하여 Phosphorous를 ELA방법으로 제조된 Poly-Si에 가속 전압 및 조사량을 변수로 이온 주입하였다. As-implanted된 시편의 결정도는 UV-transmittance spectroscopy를 사용하여 측정하였다. 이 때 UV-transmittance를 이용하여 측정한 값은 Raman spectroscopy를 이용해서 측정한 값과 서로 관련되어 있음을 알았다. 면 저항은 가속전압이 1kV에서 15kV까지 증가함에 따라 감소한다 그러나 가혹한 도핑조건하에서는 가속전압의 증가 시 면 저항이 증가한다. 이는 활성화 열처리 후 치유되지 않은 결함에 의해 전자가 포획되며 이에 따라 전하 운반자의 농도가 감소하는 때문이다. 활성화 열처리는 로열처리, RTA 열처리, ELA 열처리 등의 방법으로 수행하였고 열처리 방법에 따르는 도펀트의 활성화 및 결함의 회복의 거동을 연구하였다 Ion shower doping with a main ion source of $P_2H_x$ using a source gas mixture of $PH_3/H_2$ was conducted on excimer-laser-annealed (ELA) poly-Si.The crystallinity of the as-implanted samples was measured using a UV-transmittance. The measured value using UV-transmittance was found to correlate well with the one measured using Raman Spectroscopy. The sheet resistance decreases as the acceleration voltage increases from 1kV to 15kV at the moderate doping conditions. It, however, increases as the acceleration voltage increases under the severe doping conditions. The reduction in carrier concentration due to electron trapping at uncured damage after activation annealing seems to be responsible for the rise in sheet resistance. Three different annealing methods were investigated in terms of dopant-activation and damage-recovery, such as furnace annealing, excimer laser annealing, and rapid thermal annealing, respectively.

건축계획과 방재

김동민,Kim, Dong-Min 한국화재보험협회 1974 防災와 保險 Vol.3 No.-

빠른 손실 감지를 이용한 TCP NewReno 분석

김동민,한제찬,김석규,임차식,이재용,Kim Dong min,Han Je chan,Kim Seog gyu,Leem Cha sik,Lee Jai yong 한국통신학회 2005 韓國通信學會論文誌 Vol.30 No.3B

무선 통신 환경은 WiBro 등과 같은 새로운 무선 통신 기술들을 이용함에 따라 고속 인터넷 접속이 가능하도록 빠르게 변화하고 있다. 이에 따라 무선 구간에서 TCP(Transmission Control Protocol)를 이용한 신뢰성 있는 데이터 전송도 늘어날 전망이다. TCP는 유선상에서 사용될 목적으로 디자인되었기 때문에 유선과 다른 환경, 특히 무선에서 사용될 때에는 비 혼잡 손실에 의해 성능 저하를 겪게 된다. 특히 RTO(Retransmission Timeout)은 TCP의 성능에 많은 영향을 미친다. 본 논문에서는 기존 연구를 바탕으로 손실 복구 확률을 분석하고, 모의실험 결과를 통해 제안 알고리듬이 fast recovery 과정 중에 발생한 패킷 손실을 빠르게 감지하여 RTO없이 복구함으로써 성능 저하를 줄일 수 있음을 보인다. Wireless communication environment is changing rapidly as we use new wireless communication technology such as WiBro to access high speed Internet. As a result, reliable data transmission using TCP is also expected to increase. Since TCP assumes that it is used in wired network, TCP suffers significant performance degradation over wireless network where packet losses are related to non-congestion loss. Especially RTO imposes a great performance degradation of TCP. In this paper, we analyze the loss recovery probabilities based on previous researches, and use simulation results of our algorithm to show that it prevents performance degradation by quickly detecting and recovery losses without RTO during fast recovery.