수직원통형 빙축열조내 외향용융과정시 열전달특성에 관한 연구 -작동유체의 유동방향 및 축열조 형상비에 따른 열성능 비교-

김동환,김동춘,김일경,김영기,임장순,Kim, D.H.,Kim, D.C.,Kim, I.G.,Kim, Y.K.,Yim, C.S. 대한설비공학회 1997 설비공학 논문집 Vol.9 No.2

During the day time in summer, peak of air conditing load, and electric power management system lies under overloaded condition. The reason is the enlarged peak load value of electric power caused by increased air-cooling load in summer. To prevent load concentration during day time and overloaded condition of power management system, some energy storage methods are suggested. One of these methods is ice storage system. Water has some good properties as P.C.M.(Phase Chang Material) : Its melting point is the range of required operation temperature. It has large specific latent heat and is chemically stable compared to other organic or inorganic substances. It is cheap and easy to treat. This study represents experimental results of heat transfer characteristics of P.C.M. under the outward melting process in a vertical cylinder. We experimented with twelve combinations of conditions, i.e., three different inlet temperatures($7^{\circ}C,\;4^{\circ}C\;and\;1^{\circ}C$), two working fluid directions(upward and downward), and two aspect ratios, H/R(4 and 2). At the inlet temperature of $7^{\circ}C$ and $4^{\circ}C$, there was temperature stagnation region where the temperature of P.C.M. remains constant at $4^{\circ}C$ regardless of aspect ratio and direction of working fluid. This temperature stagnation occurs as the water, at its maximum density, flows down to the lower region. The phase change interface formed bell-shaped curve as the melting process continued. With a new set of conditions(4H/R, inlet temperature $4^{\circ}C$ and $1^{\circ}C$, downward/upwerd inlet direction), the movement of phase change interface was faster when the working flued inlet direction was downward. With the same set of conditions, melting rate and total melting energy were larger when the working fluid inlet direction was downward. The results were reversed when the other sets of conditions were applied.

귤응애에 대한 팔라시스이리응애의 포식특성

김동환,김상수,김광식,현재욱,Kim, Dong-Hwan,Kim, Sang-Soo,Kim, Kwang-Sik,Hyun, Jae-Wook 한국응용곤충학회 2006 한국응용곤충학회지 Vol.45 No.2

감귤의 중요 해충인 귤응애의 생물적 방제를 위한 목적으로 귤응애에 대한 팔라시스이리응애의 포식특성을 조사하였다. 25$^{\circ}C$ 항온조건에서 귤응애의 알, 유충, 전약충, 후약충에 대한 팔라시스이리응애 암성충의 1일간 포식량은 각각 20.1, 26.1, 18.2, 7.4개체로 유충에 대한 포식량이 가장 많았다. 온도에 따른 포식량 조사결과, 온도가 높을수록 포식량이 증가하였으며, 이 때 팔라시스이리응애가 귤응애 알을 포식한 후의 출산능력(팔라시스이리응애 출산 알수/포식된 귤응애 알수), 즉 전환율은 10$^{\circ}C$를 제외하고는 0.09로 일정하였다. 잎 절편의 지름을 각각 20, 40, 60 mm로 하여 귤응애 알을 먹이로 공급했을 때 1일간 포식량은 각각 21.1, 17.3, 16.7개로 잎 면적이 증가할수록 포식량은 감소하였다. 또한 팔라시스이리응애는 귤응애 알, 유충, 약충을 먹이로 공급하였을 때 먹이밀도가 증가할수록 포식량은 점차 증가하였으나 그 증가율은 점차 감소하는 Holling의 기능반응 H형의 특성을 보였다. 이상의 시험결과 팔라시스이리응애는 귤응애의 생물적 방제 인자로서 가치가 있는 것으로 판단된다. Predation of Neoseiulus fallacis was observed for biological control of Panonychus citri that is one of the major insect pests on citrus. The daily predation of development stages of P. citri by an adult female of N. fallacis were 20.1 eggs, 26.1 larvae, 18.2 protonymphs, and 7.4 deutonymphs at 25$^{\circ}C$, The daily predation of P. citri eggs by N, fallacis was observed under different temperatures. The predation was increased as the temperature rise. At this time, ratio of eggs production of l! fallacis after predation of P. citri eggs (number of eggs N. fallacis/number of eggs P. citri consumed by N. fallacis) was 0.09. The daily predation of P. citri eggs by N, fallacis was 21.1, 17.3, and 16.7 on the different arenas (diameter: 20, 40, and 60 mm), respectively. The predation was decreased as the arena of the leaf increase. The functional response of M fallacis to P. citri showed Holling's Type II response: the consumption of prey by N. fallacis increased as the density of prey increase but increasing rate was gradually reduced. As the result, it seemed that N. fallacis can be use for biological control of P. citri.

열적, 화학적 강화에 의해 잔류응력이 형성된 유약층을 가진 도자기의 기계적 물성

김동환,맹지헌,한윤수,김형태,최성철,김형준,Kim, Dong-Hwan,Maeng, Jee-Hun,Han, Yoon Soo,Kim, Hyung-Tae,Choi, Sung-Churl,Kim, Hyeong-Jun 한국세라믹학회 2014 한국세라믹학회지 Vol.51 No.5

In this study, we measured the thermally and chemically induced residual stresses on glaze using the photoelastic method. Porcelain with thermally induced residual stress showed compressive stress of 49 MPa for thermal expansion mismatch and a locally fluctuated stress field over the glaze layer due to compensation of compressive stresses around pores. In the case of chemically strengthened porcelain, the compressive stress on the glaze was 151 MPa which was around 3 times higher than the stress on thermally strengthened glaze. The trend of fracture strength of thermally and chemically strengthened porcelains was coincident with that of the residual stress of porcelains.

SnO-P₂O₅계 유리에서 P₂O₅를 B₂O₃로 치환시 구조와 물성에 미치는 영향

김동환,황차원,김남진,임상혁,구동건,김태희,차재민,류봉기,Kim, Dong-Hwan,Hwang, Cha-Won,Kim, Nam-Jin,Im, Sang-Hyeok,Gwoo, Dong-Gun,Kim, Tae-Hee,Cha, Jae-Min,Ryu, Bong-Ki 한국세라믹학회 2011 한국세라믹학회지 Vol.48 No.1

The investigation is directed to lead free (Pb-free) frits that can be used for organic light emitting diode, plasma display screen devices and other sealing materials. $P_2O_5$-SnO system glasses have been prepared for Pb-free low temperature glass frit. Structure and properties of the glasses with the composition SnO-$xB_2O_3-(60-x)P_2O_5$ (x=0, 5, 10, 15, 20, 25, 30, 35, 40 mol%) were characterized by infrared spectra (IR), X-ray diffraction(XRD), Density, Molar volume, Thermo mechanical analysis(TMA) and weight loss after immersion test. Glass transition temperature($T_g$), dilatometric softening temperature($T_d$) and chemical durability increased, and coefficient of thermal expansion($\alpha$) decrease with the substitution of $B_2O_3$ for $P_2O_5$ in the range of 0~25 mol%.

팔라시스이리응애에 대한 농약의 독성

김동환,김상수,김광식,현재욱,Kim, Dong-Hwan,Kim, Sang-Soo,Kim, Kwang-Sik,Hyun, Jae-Wook 한국응용곤충학회 2006 한국응용곤충학회지 Vol.45 No.2

감귤 병해충 방제용으로 사용되고 있는 37종의 약제에 대한 팔라시스이리응애의 감수성을 조사한 결과, difenoconazole, imibenconazole, azoxystrobin, dithianon, fluazinam, procymidon, streptomycin, tribasic copper sulfate 등의 살균제 8종과 dichlovos, imidacloprid, thiamethoxam 등의 살충제 3종, 그리고 milbemectin, tetradifon, dicofol, spirodiclofen 등의 살비제 4종은 팔라시스이리응애 알의 부화율에 대한 영향이 적었으며, propineb, difenoconazole, imibenconazole, azoxystrobin, dithianon procymidon 등의 살균제 6종과 bifenazate, tetradifon, spirodiclofen 등의 살비제 3종은 성충에 대한 독성이 낮았다. 농약이 살포된 점박이응애 알을 먹이로 공급하여 성충에 대한 이차독성을 검정한 결과, 살균제 2종(fluazinam, streptomycin)과 살비제 3종(machine oil, cyhexatin, halfenprox)이 독성이 낮은 것으로 나타났다. The toxicities of 37 commercial pesticides for citrus pests were evaluated to H, fallacis. Eight fungicides (difenoconazole, imibenconazole, azoxystrobin, dithianon, fluazinam, procymidon, streptomycin, tribasic copper sulfate), three insecticides (dichlovos, imidacloprid, thiamethoxam) and four acaricides (milbemectin, tetradifon, dicofol, spirodiclofen) had lower effect to the hatchability of eggs N. fallacis. Six fungicides (propineb, difenoconazole, imibenconazole, azoxystrobin, dithianon, procymidon) and three acaricides (bifenazate, tetradifon, spirodiclofen) showed lower contact toxicity to adult N. fallacis. The secondary toxicity of 26 pesticides to N. fallacis adult were evaluated. Two fungicides (fluazinam, streptomycin) and 3 acaricides (machine oil, cyhexatin, halfenprox) showed low toxicity when the prey (eggs of spider mite) was treated with pesticides.

Squeezing in a Josephson-junction-based Parametric Amplifier

김동환,김덕영,김재일,이수용,Kim, Dong-Hwan,Kim, Deok-Yeong,Kim, Jae-Il,Lee, Su-Yong 한국초전도저온학회 2022 초전도와 저온공학 Vol.24 No.1

Isolation of putative pepper defense-related genes against the pathogen Phytophthora capsici using suppression subtractive hybridization/macroarray and RNA-sequencing analyses

김동환,강원희,Seon-In Yeom,Byung-Dong Kim 한국원예학회 2019 Horticulture, Environment, and Biotechnology Vol.60 No.5

The oomycete Phytophthora capsici Leonian is one of the most economically important pathogens limiting pepper ( Capsicumannuum ) production in many regions around the world. Insights into the defense mechanisms of pepper against P. capsiciwould be helpful in the breeding of resistant cultivars. However, little is still known about the defense system in pepperagainst P. capsici . We used suppression subtractive hybridization (SSH) followed by macro-array screening to isolate theputative candidate defense genes (PSH, Phytophthora Subtractive Hybridization) in pepper that are diff erentially expressedbetween the resistant cultivar ( CM334 ) and the susceptible cultivar ( Chilsungcho ) following P. capsici infection. A total of72 PSH genes were identifi ed and categorized based on their putative functions. Semi-quantitative RT-PCR analyses using11 selected genes confi rmed their diff erential expressions between the resistant and susceptible cultivars along the timecourse of infection with P. capsici . Furthermore, RNA-seq analyses were performed to understand the possible roles of PSHgenes in the defense response to P. capsici as well as three viruses, including two tobacco mosaic virus strains and one PepperMottle Virus strain. We found that 37 genes out of 72 displayed diff erential expression in our RNA-seq-based heatmapbetween ‘ CM334 ’ and ‘ Chilsungcho ’ upon pathogen infection. In particular, two genes, CA00g99220 and CA00g96010,and one gene, CA12g16620, were shown to be strongly and uniquely expressed in the resistant cultivar, CM334, against P. capsici and two viruses, respectively. Thus, we consider that this combined approach using SSH/macro-array screening andRNA-seq analyses is a relevant tool for isolation of candidate defense-related genes upon pathogen infection. Data in thisstudy provide a good source for further study on the defense mechanisms against pathogens in chili pepper.

한랭치료가 급성 류마티스 관절염 환자의 염증완화에 미치는 효과

김동환,박래준,전경희,Kim, Dong-Hwan,Park, Rae-Joon,Jun, Kyoung-Hee 대한물리치료학회 2001 대한물리치료학회지 Vol.13 No.1

The purpose of this study was to investigate the effect of the cold air application for release of inflamation and pain in patient with acute rheumatoid arthritis who had taken medication(NSAIDs, DMARDs, corticosteroids). The participants had knee joint pain and ESR score over the 30. They were randomly assigned to three groups with each 15. Control group(group I ) were applied cold air and medication, experimental group II were applied hot pack and medication. and experimental group III were applied only medication. They were evaluated from April 1, 2000 to september 1,2000 ,and it was examined by ESR and VAS(visual analoge scale) in Lee Bang Hoon rehabilitation medicine clinic in Jeju Korea. The result of this study were as follow: 1. It was found that group 1, group II and group III had the statistically significant reduction of the ESR score according to treatment time(p<.05). 2. There were not statistically significant differences in ESR change pattern of each group according to treatment time(p>.05). 3. There were not statistically significant differences in the change of ESR according to treatment time between group I and group II , group I and group III , and group II and group III (p<.05). 4. It was found that group I . group II and group III had the statistically significant reduction of the VAS(Visual Analoge Scale) score according to treatment time(p<.05). 5. There were statistically significant differences in VAS score according to treatment time between control group(group I ) and experimental groups(group II and group III)(p<.05), but there were not stsiistically significant differences between experimental groups(p>.05).

표면 법선 기반의 삼각형 메쉬 영역화 기법

김동환,윤일동,이상욱,Kim, Dong-Hwan,Yun, Il-Dong,Lee, Sang-Uk 대한전자공학회 2002 電子工學會論文誌-SP (Signal processing) Vol.39 No.2

본 논문에서는 삼각형으로 이루어진 3차원 메쉬 데이터의 영역화에 대한 알고리듬을 서술한다. 제안하는 알고리듬은 메쉬 표면을 구성하는 삼각형들의 방향성에 기반한 것으로, 인접한 삼각형 쌍들의 반복적인 병합을 이용한다 메쉬 표면은 각각의 영역이 비슷한 법선 벡터를 가지는 삼각형들로 구성되도록 여러 개의 영역으로 영역화된다. 따라서 각 영역은 평면 조각으로 근사될 수 있으며, 각 영역의 경계선은 인간이 전체 메쉬 모델을 지각적으로 이해하는데 있어서 중요한 기하학적인 정보를 포함한다. 실험 결과는 제안하는 알고리듬이 효율적으로 동작하고 있음을 보여준다. This paper presents an algorithm for segmentation of 3D triangular mesh data. The proposed algorithm uses iterative merging of adjacent triangle pairs based on the orientation of triangles. The surface is segmented into patches, where each patch has a similar normal property Thus, each region can be approximated to planar patch and its boundaries have perceptually important geometric information of the entire mesh model. The experimental results show that the Proposed algorithm is peformed efficiently.

명사칼럼 2 - 인구구조의 변화와 농식품 소비패턴

김동환,Kim, Dong-Hwan 대한두채협회 2008 물만 먹고 자라요 Vol.20 No.-