딥러닝 기반 사용자 최적화 스마트 홈 시스템

강경민,함지혜,박동규 순천향대학교 산업기술연구소 2022 순천향 산업기술연구소논문집 Vol.28 No.2

With the 4th industrial revolution IT technologies such as AI and IoT lead the era and AIoT technologies that combine them are currently developing. This paper develops user-optimized smart home system based on deep learning and supplements the security vulnerabilities of IoT services with AES encryption algorithms. The proposed system by this paper implements a deep learning model to learn, predict and provide user-optimized temperatures according to the current temperature and humidity and location. The state of the smart home is divided into automatic and manual and when in automatic mode the cooling and heating system is operated by predicting the user-optimized temperature according to the current temperature, humidity data and the user's location in real time. The smart home proposed by this paper not only increases user convenience but also enables efficient energy management.

Anisotropic Thermal Interface Materials: Directional Heat Transfer in Uniaxially Oriented Liquid Crystal Networks

Kang, Dong-Gue,Ko, Hyeyoon,Koo, Jahyeon,Lim, Seok-In,Kim, Jin Soo,Yu, Yeon-Tae,Lee, Cheul-Ro,Kim, Namil,Jeong, Kwang-Un American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.41

<P>For the development of anisotropic thermal interface materials (TIMs), a rod-shaped reactive monomer PNP-6MA is newly designed and successfully synthesized. PNP-6MA reveals a smectic A (SmA) mesophase between crystalline (K) and isotropic (I) phases. PNP-6MA can be oriented under a magnetic field (<I>B</I> = 2 T), and its macroscopic orientation can be robustly stabilized by in situ polymerization. Even without macroscopic orientations, the fabricated thermal conducting liquid crystal (TCLC) films show the outstanding thermal conductivity of 1.21 W/m K, which is higher than conventional organic materials. The thermal conductivity of uniaxially and macroscopically oriented TCLC films can be 2.5 W/m K along the long axis of mesogenic core. The newly developed TCLC film can be used as a TIM between a high-power light-emitting diode and a heat sink.</P> [FIG OMISSION]</BR>

Heat Transfer Organic Materials: Robust Polymer Films with the Outstanding Thermal Conductivity Fabricated by the Photopolymerization of Uniaxially Oriented Reactive Discogens

Kang, Dong-Gue,Park, Minwook,Kim, Dae-Yoon,Goh, Munju,Kim, Namil,Jeong, Kwang-Un American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.44

<P>For the development of advanced heat transfer organic materials (HTOMs) with excellent thermal conductivities, triphenylene-based reactive discogens, 2,3,6,7,10,11-hexakis(but-3-enyloxy)triphenylene (HABET) and 4,4',4 '',4 '''',4 '''''', 4 '''''' '/(triphenylene-2,3,6,7,10,11-hexaylhexakis(oxy))hexakis(butane-l-thiol) (THBT), were synthesized as discotic liquid crystal (DLC) monomers and cross-linkers, respectively. A temperature composition phase diagram of HABET-THBT mixtures was first established based on their thermal and microscopic analyses. From the experimental results, it was realized that the thermal conductivity of DLC HTOM was strongly affected by the molecular organizations on a macroscopic length scale. Macroscopic orientation of self-assembled columns in DLC HTOMs was effectively achieved under the rotating magnetic fields and successfully stabilized by the photopolymerization. The DLC HTOM polymer-stabilized at the LC phase exhibited the remarkable thermal conductivity above 1 W/mK. When the DLC HTOM was macroscopically oriented, the thermal conductivity was estimated to be 3 W/mK along the in-plane direction of DLC molecule. The outstanding thermal conductivity of DLC HTOM should be originated not only from the high content of two-dimensional aromatic discogens but also from the macroscopically oriented and self-assembled DLC. The newly developed DLC HTOM with an outstanding thermal conductivity as well as with an excellent mechanical sustainability can be applied as directional heat dissipating materials in electronic and display devices.</P>

Interfacial Engineering for the Synergistic Enhancement of Thermal Conductivity of Discotic Liquid Crystal Composites

Kang, Dong-Gue,Kim, Namil,Park, Minwook,Nah, Changwoon,Kim, Jin Soo,Lee, Cheul-Ro,Kim, Youngsu,Kim, Chae Bin,Goh, Munju,Jeong, Kwang-Un American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.4

<P>To develop an advanced heat, transfer composite a deeper understanding of the interfacial correlation between matrix and filler is of paramount importance. To verify the effect of interfacial correlations on the thermal conductivity, the conductive fillers such as expanded graphite (EG) and boron nitride (BN) are introduced in,the discotic liquid crystal (DLC)-based polymeric matrix. The DLC matrix exhibits better interfacial affinity with EG compared to BN because of the strong pi-pi interactions between EG and DLC. Thanks to its excellent interfacial affinity, the EG-DLC composites show a synergistic increment in thermal conducting performance.</P>

0.25 μm AlGaN/GaN HEMT 소자 및 9 GHz 대역 전력증폭기

강동민(Dong-Min Kang),민병규(Byoung-Gue Min),이종민(Jong-Min Lee),윤형섭(Hyung-Sup Yoon),김성일(Sung-Il Kim),안호균(Ho-Kyun Ahn),김동영(Dong-Young Kim),김해천(Hae-Cheon Kim),임종원(Jong-Won Lim),남은수(Eun-Soo Nam) 한국전자파학회 2016 한국전자파학회논문지 Vol.27 No.1

본 논문에서는 ETRI에서 개발된 50 W GaN-on-SiC HEMT 소자를 이용하여 X-band에서 동작하는 50 W 펄스 전력증폭기의 개발 결과를 정리하였다. 제작된 50 W GaN HEMT 소자는 0.25 μm의 게이트 길이를 갖고, 총 게이트 폭은 12mm인 소자이다. 펄스 전력증폭기는 9.2~9.5 GHz 주파수 대역에서 50 W의 출력전력과 6 dB의 전력이득 특성을 나타내었다. 전력소자의 전력밀도는 4.16 W/mm이다. 제작된 GaN-on-SiC HEMT 소자와 전력증폭기는 X-대역 레이더 시스템등 다양한 응용분야에 적용이 가능할 것으로 판단된다. This paper describes the successful development and the performance of X-band 50 W pulsed power amplifier using a 50 W GaN-on-SiC high electron mobility transistor. The GaN HEMT with a gate length of 0.25 μm and a total gate width of 12 mm were fabricated. The X-band pulsed power amplifier exhibited an output power of 50 W with a power gain of 6 dB in a frequency range of 9.2~9.5 GHz. It also shows a maximum output power density of 4.16 W/mm. This 50 W GaN HEMT and X-band 50 W pulsed power amplifier are suitable for the radar systems and related applications in X-band.

X-대역 50 W급 펄스 모드 GaN HEMT 내부 정합 전력 증폭기

강현석(Hyun-Seok Kang),배경태(Kyung-Tae Bae),이익준(Ik-Joon Lee),차현원(Hyen-Won Cha),민병규(Byoung-Gue Min),강동민(Dong-Min Kang),김동욱(Dong-Wook Kim) 한국전자파학회 2016 한국전자파학회논문지 Vol.27 No.10

본 논문에서는 0.25 μm GaN HEMT 공정을 사용하여 ETRI에서 개발된 80×150 μm의 트랜지스터를 사용하여 X-대역에서 동작하는 50 W급 내부 정합 전력 증폭기를 설계 및 제작하였다. 임피던스 변환용 사전 정합 회로를 사용한 로드풀 측정으로 최적의 소스 및 부하 임피던스를 실험적으로 추출하였고, 성능을 예측하였다. 유전율 10.2의 기판을 사용하여 제작된 내부 정합 전력 증폭기의 전력 성능은 펄스 주기 100 μs, 듀티 10 %의 펄스 모드 조건에서 측정되었으며, 최대 성능으로는 9.2 GHz에서 47.46 dBm(55.5 W)의 출력 전력과 46.6 %의 전력부가효율이 측정되었다. 9.0~9.5 GHz의 주파수에서 출력 전력은 47~47.46 dBm(50~55.7 W)의 값이 측정되었고, 전력부가효율은 9.0~9.3 GHz에서 43 % 이상, 9.4~9.5 GHz에서는 36 % 이상의 효율이 측정되었다. In this paper, an X-band 50 W internally matched power amplifier is designed and fabricated using an 80×150 μm GaN HEMT that is developed by the 0.25 μm GaN HEMT process of ETRI. The optimum source and load impedances are experimentally extracted from the loadpull measurement using impedance-transform-prematching circuits, and the transistor performance is predicted. The power performance of the internally matched power amplifier, whose matching circuits are fabricated on a substrate with εr of 10.2, is measured under the pulsed mode of 100 μs pulse period and 10 % duty cycle, and the best output power of 47.46 dBm(55.5 W) and the power-added efficiency of 46.6 % are obtained at 9.2 GHz. The output power of 47~47.46 dBm(50~55.7 W) is measured in 9.0~9.5 GHz, and the power-added efficiency is measured to be greater than 43 % in 9.0~9.3 GHz and above 36 % in 9.4~9.5 GHz.

혈액투석으로 치료한 급성 신부전의 예후인자

곽귀철(Gue Chuel Kwak),오동진(Dong Jin Oh),이준승(Jun Seung Lee),박지현(Joe Hyoun Park),강응택(Eung Taek Kang),유석희(Suk Hee Yu) 대한내과학회 1995 대한내과학회지 Vol.48 No.4

Objectives: Acute renal failure continues to be associated with a high mortality despite advances in dialysis and care of the critically ill patient. Although there have been many clinical studies on acute renal failure in Korea, none of them have investigated the prognostic factors in acute renal failure managed with hemodialysis. Methods : We reviewed retrospectively 115 patients with acute renal failure who had been hospitalized and hemodialyzed at the Department of Internal Medicine, Chung-Ang University Hospital between October 1984 and July 1993. Results: 1) The overall mortality was 50.4% with the mean age of nonsurvivors higher than that of survivors(54 ±7.2 vs 44±18.9 years, p<0.05). The mortality was higher in older age, especially patients over 60 years( p = 0.0031). 2) According to the complications, the mortality was 100% in acute myocardial infarction, 100% in coma, 93.1% in persistent hypotension, 86.2% in respiratory failure, 77.5% in infection, 73.3% in jaundice, and 38.3% in pneumonia. The presence of complications were closely related to the prognosis of acute renal failure(p<0.05). 3) The hematocrit and the increase of BUN during hemodialysis was closely related to the prognosis of acute renal failure(29.0 vs 32.3, 17.1mg/dL/day vs 11.9mg/dL/day, p <0.05). 4) According to Liano's discriminant score, our mean score was 0.343 in survivors & 0.565 in nonsurvivors, and our cutoff point was lower than that of Liano's score.(0.611 vs 0.856) Conclusion : The poor prognostic factors in acute renal failure managed with hemodialysis were old age, presence of infection, persistent hypotension, acute myocardial infarction, jaundice, respiratory failure, pneumonia, hematocrit and the increase of BUN during dialysis. Because Liano's discriminant score was insufficient as prognostic indices for itself, other objective prognostic indices should be studied.

한국인 악성 고혈압의 임상적 고찰

오동진(Dong Jin Oh),이준승(Jun Seung Lee),박지현(Jee Hyun Park),곽귀철(Gue Chul Gawk),강응택(Eung Taek Kang),유석희(Suk Hee Yu) 대한내과학회 1995 대한내과학회지 Vol.48 No.6

Objectives: Prior to the development of effective antihypertensive regimen and renal replacement therapy, malignant hypertension regarded as a bad prognostic disease. Sine 1960 with the early detection of hypertension and the introduction of new potent antihypertensive regimens and renal replacement therapy, there were several reports of etiologic changes and improving survival rates. However there has been a few reports concerning malignant hypertension in 1990s and never reported in Korea so far. The purpose of this study is to know the cause, clinical feature and survival rate of malignant hypertension in Korean, Method: The definition of malignant hypertension is characterized as grade III or IV hypertensive retinopathy according to Keith-Wagener-Barkers classification. we reviewed 107 patients with malignant hypertension who visited our department between 1988 and 1993 retrospectively. Results: The mean age of essential hypertension was 56years, renal lesion 37years, renovascular lesion 45years, and that of unknown cause was 41years, The mean blood pressure of essential hypertension was 209mmHg/128mmHg, renal lesion 194mmHg/120mmHg, renovascular lesion 210mmHg/130mmHg, and that of unknown cause was 183mmHg/125mmHg. The initial serum creatinine of essential hypertension was 2.45±2.51mg/dl, renal lesion 8.10±7.56mg/dl, renovascular lesion 1.95±0.35mg/dl, and that of unknown cause was 15.44±10.24mg/dl. Essential hypertension was diagnosed in 56 cases (53%), secondary hypertension in 40 cases (37%) and unknown cause in 11 cases(10%). The One year patient was 92% and 5 year survival survival 51%. The 5 year patient survival of essential hypertension was 85% and that of secondary hypertension was 86%. The 5year patient survival was 92% in the group of initial serum creatinine <3mg/dl, but 81% in the group of inital serum creatinine >3mg/dl. Ten patients died. Of these, three patients died of cerebrovascular accident, three patients died of hyperkalemia. Other causes of death were pulmonary edema, hepatic encephalopathy, lung cancer, and socioeconomic factor. Conclusion: the main cause of malignant hypertension in Korea was primary hypertension and survival rates were similar to recent other reports.

하지 동맥경화증의 수술 전 진단에서 고식적 혈관조영술과 다중검출 나선식 컴퓨터 혈관조영술의 비교

이강율(Kang Yool Lee),김일명(Il Myung Kim),유병욱(Byung Ook You),윤진(Jin Yoon),박상수(Sang Su Park),신동규(Dong Gue Shin),강성구(Sung Gu Kang),황호경(Ho Kyung Hwang),이성아(Sung A Lee) 대한외과학회 2008 Annals of Surgical Treatment and Research(ASRT) Vol.74 No.4

Purpose: We performed this study to assess the suitability of conventional angiography (CA) vs. multi-detector row helical CT angiogram (MD-CTA) as a method of preoperative diagnostic imaging for low extremity arterial surgery. Methods: From February 2004 to September 2006, 23 patients (4 claudicants, 19 limb-threatening ischemia) were studied with CA and MD-CTA preoperatively. The site and degree of stenotic or occlusive lesions in arterial segments from the renal artery to the dorsalis pedis artery were compared with both methods. We also compared the surgical inflow and outflow site changes in preoperative planning based on CA and MD-CTA and the final outcome. Additional diagnostic value and test-related complications were also analyzed. Results: The median age of patients was 68 years old (range: 43∼89 years), with a male to female ratio of 1.3:1. Twenty-three patients had CA after an MD-CTA scan. One hundred fifty lesions were detected in these patients. The total ratio of consistency for occlusion in CA vs. MD-CTA was 69.6%. Three patients received amputation treatment and eleven patients received a bypass operation. The agree ment between the preoperative plan based on MD-CTA and the final operation was 100%, even in critical limb ischemia. There were no serious complications related to the tests. Conclusion: These findings suggest that MD-CTA is an adequate preoperative imaging study of infrainguinal arterial surgery and may be substituted for conventional angiography without any serious complications.

우주급 고 신뢰성 Custom Flexible Heater 소자개발 및 검증현황

김동환(Dong Hwan Kim),염치선(Chi Seon Yeom),김명길(Myung- gil Kim),윤강퇴(Kang-Toi Yoon),송규봉(Gue- Bong Song) 한국항공우주학회 2023 한국항공우주학회 학술발표회 논문집 Vol.2023 No.6