현장측정 창-벽체 접합부 선형열관류율 도출을 위한 시뮬레이션 기초연구

최재솔(Choi, Jae-Sol),김창민(Kim, Chang-Min),장향인(Jang, Hyang-In),김의종(Kim, Eui-Jong) 한국건축친환경설비학회 2020 한국건축친환경설비학회 논문집 Vol.14 No.2

This paper is a preliminary study on a quantitative evaluation of the thermal bridge through window-wall joint based on infrared thermography. The purpose of the work is to check the possibility of deducing the linear thermal transmittance from the thermal images, but in this preliminary work, the images were obtained not from an infrared camera but from simulations. A reference model is proposed to describe a construction defect case on the window-wall joint. Above all, the linear thermal transmittance of the defect case and the reference model was derived through the steady-state simulation. The reference model could describe the defective case showing a similar linear thermal transmittance when iteratively modifying a joint thermal property of the reference model. Surface temperatures of the surrounding area of the window were checked under unsteady conditions, and the temperature difference was 0.012°C on average. This result may show that the similar process can be performed but inversely in in-situ tests to get the linear thermal transmittance by modifying the joint property to match the thermal image and the simulated surface temperatures.

현장측정 창-벽체 접합부 선형열관류율 도출을 위한 시뮬레이션 기초연구

최재솔(Choi, Jae-Sol),김창민(Kim, Chang-Min),장향인(Jang, Hyang-In),김의종(Kim, Eui-Jong) 한국건축친환경설비학회 2020 건축환경설비 Vol.14 No.2

This paper is a preliminary study on a quantitative evaluation of the thermal bridge through window-wall joint based on infrared thermography. The purpose of the work is to check the possibility of deducing the linear thermal transmittance from the thermal images, but in this preliminary work, the images were obtained not from an infrared camera but from simulations. A reference model is proposed to describe a construction defect case on the window-wall joint. Above all, the linear thermal transmittance of the defect case and the reference model was derived through the steady-state simulation. The reference model could describe the defective case showing a similar linear thermal transmittance when iteratively modifying a joint thermal property of the reference model. Surface temperatures of the surrounding area of the window were checked under unsteady conditions, and the temperature difference was 0.012°C on average. This result may show that the similar process can be performed but inversely in in-situ tests to get the linear thermal transmittance by modifying the joint property to match the thermal image and the simulated surface temperatures.

Trimethyl - indium 소스 고갈에 따른 InGaAsP 에피층의 특성 변화

김현수(Hyun Soo Kim),오대곤(Dae Kon Oh),편광의(Kwang Eui Pyun),최인훈(In Hoon Choi) 한국진공학회(ASCT) 2000 Applied Science and Convergence Technology Vol.9 No.4

유기금속 소스의 농도를 연속적으로 in-situ 측정이 가능한 EPISON ultrasonic monitor를 이용하여 TMIn(trimethly-indium)의 소스 고갈이 InGaAs, InGaAsP bulk 에피층과 1.55 ㎛ InGaAs/InGaAsP SMQW(strained multi-quantum well)에 미치는 영향을 조사하였다. TMIn 소스는 사용량이 80%에서 급격하게 소스 고갈 현상을 보였다. TMIn 소스는 사용량이 80%에서 급격하게 소스 고갈 현상을 보였다. TMIn 소스 고갈에 의한 에피층의 특성 변화를 조사한 결과, bulk 에피층의 경우에는 소스가 고갈 되기전에 성장한 에피층과 비교하여 DCXRD(double crystal X-ray diffractometry) spectrum에서 피크 분리가 약 300 arcsec정도 Ga-rich 방향으로 이동하였으며 relative FWHM은 약 2배 가량 증가하는 것을 보였다. SMQW 구조에서는 bulk 에피층과는 달리, PL 중심파장에서도 약 40 ㎚ 정도 단파장쪽으로 이동하였으며, 피크 분리는 약 300 arcsec정도 Ga-rich 방향으로 이동하였다. 하지만, EPISON의 closed loop 기능을 사용할 경우에는 TMIn 소스 사용량이 95%에서도 피크 분리가 ±100 arcsec이내의 재현성 있는 에피층 성장이 가능하다는 것을 알 수 있었다. We investigated the effect of TMIn (trimethly-indium) source depletion on InGaAs, InGaAsP and 1.55 ㎛ InGaAs/InGaAsP SMQW by using EPISON ultrasonic monitor for measuring the concentration of metalorganiclcarrier gas mixtures. And the problems for the growth reproducibility in MOCVD was solved by using an EPISON ultrasonic monitor with closed-loop mode under the condition of TMIn source depletion. The saturation pressure of TMIn was dramatically decreased over consumption of 80%. In the case of bulk epilayer, Up-shifting of 300 arcsec to Ga-rich direction and FWHM broadening by a factor of two in DCXRD spectrum were observed due to the TMIn source depletion. In the case of SMQW, Up-shifting of 300 arcsec to Ga-rich direction in DCXRD spectrum and blue-shift of 40 ㎚ in PL spectrum were observed due to the TMIn source depletion. However, good reproducibility(△θ<±100 arcsec) was achieved even the condition of 95% of TMIn consumption, when we used the EPISON with closed-loop mode.

쥐치아 치근면의 치주인대세포의 활성도를 평가하는 방법으로 MTT검색법의 적절성에 대한 조직학적인 검증

김현기,김의성,최인복,김진,이승종 大韓齒科保存學會 2003 Restorative Dentistry & Endodontics Vol.28 No.5

The purpose of this study is to examine the viability of PDL cells in rat molars by using MTT assay and to verify the MTT assay through the histologic observation. Thirty of Sprague Dawley white female rats of 4 weeks old with a body weight of about 100 grams were used. Groupings are as follows : Immediate Group : Positive control group(n=10) after extraction immediately. Dried Group : Negative control group(n=10) after drying for an hour under warm dry. ViaSpan Group : 1hour ViaSpan group(n=10) after storing in ViaSpan at 4℃ for 1hour. Ten teeth of each group were treated as same as above and replanted to the original socket of experimental animals. After two weeks of replantation. all the experimental animals were sacrificed. And after fixation, extracted maxillary jaw was dimineralized. After it was embedded in paraffin. serial section by ViaSpan was carried out and for construction of specimen, hematoxylin eosin dye was used. The mean MTT measurement of immediate group(positive control) is 2.81 and the mean measurement of dried group(negative control) is 0.98 which is significantt differnt(P<0.05), The mean measurement of ViaSpan group is 2.65 and there is significant difference between dried group and ViaSpan group(P<0.05), However, there is no difference between immediate group and ViaSpan group. The average resorption points of immediate group is 3.03 points. In the dried group, average 6.44 points resorption and 2.68 points showed resorption in the ViaSpan group. Unlike with MTT assay, there was no significant difference between the immediate group and ViaSpan group. The usage of MTT assay as a viable cell marker may give us a better indication of the maintenance of periodontal ligament cell vitality.

N₂O 가스로 열산화된 게이트 산화막의 전기적 특성

김태형,김창일,최현식,장의구,서용진,이철인 중앙대학교 생산공학연구소 1992 생산공학연구소 논문집 Vol.1 No.2

미래의 ULSI 소자의 게이트 산화막으로 이용하기 위하여 N₂O 가스 분위기에서 기존의 전기로를 이용한 실리콘의 열산화에 의해 N₂O 산화막을 형성하였고, MOS 소자를 제작하여 전기적 특성을 고찰하였다. 900℃에서 90분간 산화한 N₂O 산화막의 경우, 플랫밴드 전압(??), 고정전하밀도(??)와 플랫밴드 전압의 변화량(??)은 각각 0.81 [V], ?? [??]와 80∼95[mV]를 나타내었다. N₂O 산화막의 전기전도기구는 저전계 영역에서는 Fowler-Nordheim 터널링, 고전계영역에서는 Poole-Frenkel 방출이 지배적으로 나타났고, 절연파괴전계는 16 [MV/㎝]로 높게 나타났다. 따라서 N₂O 산화로 형성된 게이트 산화막이 ULSI 소자의 게이트 유전체로 응용이 가능하리라 생각된다. In order to applicate gate insulators in future ULSI devices, electrical properties was investigated in MOS device with N₂O oxide grown by thermal oxidation using conventional furnace in N₂O ambient. For the sample oxidized at 900℃ for 90 min, Flatband voltage(??), fixed charge density(??) and shifts of flatband voltage(??) after BTS was obtained 0.81 [V], ?? [??] and 80∼95[mV], respectively. The dominant conduction mechanism of N₂O oxide appeared to be Fowler-Nordheim tunneling in the low electrical field region(4-6 [MV/㎝]) and to be Poole-Frenkel emission in the high electrical field region( 9 [MV/㎝] or above). Dielectrics breakdown fields of N₂O oxide appeared about 16 [MV/㎝]. These results suggest that the N₂O oxides is a promising candidate for ultrathin gate dielectric for MOS ULSI applications.

스텐트 재협착 병변에서 약물코팅 풍선카테터과 약물용출 스텐트의 예후 분석

이두환 ( Doo Hwan Lee ),송종남 ( Jong Nam Song ),박신의 ( Sin Eui Park ),최남길 ( Nam Gil Choi ),한재복 ( Jae Bok Han ),김인수 ( In Soo Kim ) 한국방사선학회 2019 한국방사선학회 논문지 Vol.13 No.3

약물용출 스텐트(drug-eluting stents, DES)는 일반 금속 스텐트에 비하여 재협착을 현저하게 줄였지만, 여전히 관상동맥 스텐트 재협착은 비율이 높다. 2012년 11월부터 2016년 12월까지의 일 대학교병원 심혈관센터에서 경피적 관상동맥 스텐트 삽입술 후 관상동맥 조영술에서 스텐트 재협착 환자 187명 그룹 I (약물코팅 풍선카테터 사용, n=127명), 그룹 II (약물용출 스텐트 사용, n=60명)로 분류하여 치료효과, 주요심장사건, 사망 발생률, 심근경색, 표적병변 재개통술 그리고 스텐트 혈전등을 2년 동안 추적 분석하였다. 임상적 특성는 두 그룹간 차이는 없었고(21.1 ± 5.3 vs. 25.3 ± 9.6 mm, p<0.002), 혈관조영검사에서 약물코팅 풍선카테터 사용 그룹에서 스텐트 재협착 길이가 짧았다. 주요심장사건은 8.7%vs.10.0%, p=0.789, 사망발생률0%vs.0%,p=1.000, 심근경색 1.6%vs.6.7%, p=0.085, 표적병변 재개통술 8.7% vs. 10.0%, p=0.789 그리고 스텐트 혈전증 0% vs. 0%, p=1000에서 양군 간에 차이를 보이지 않았다. 약물코팅 풍선카테터가 약물방출 스텐트와 비교하여 2년 추적 검사 결과 주요심장사건에서 차이가 없었고, 약물코팅 풍선카테터는 스텐트 재협착 병변에서 약물방출 스텐트와 함께 선택할 수 있는 좋은 치료방법이라고 사료된다. Although the development of Drug-eluting stent (DES) improved the ISR significantly more than the Bare metal stent (BMS), the coronary stent restenosis (ISR) treatment still has a high recurrence rate. This study is compared the efficacy of DEB with that of DES implantation in patients with ISR. Among 4,316 patients who underwent coronary stent implantation at the Chonnam National University Hospital between November 2012 and December 2016, 187 patients developed ISR on follow-up coronary angiography (66.3 ± 11.0 years, 123 males) were enrolled and divided into two groups according to revascularization method as group I (DEB group; n= 127) and group II (DES group; n= 60). Primary end point was defined as major adverse cardiac events (MACEs), composite of cardiac death (CD), myocardial infaction (MI), target lesion revascularization (TLR) and stent thrombosis (ST) during two-year follow-up between the two groups. There were no differences in the baseline characteristics and angiographic findings except that prevalence of device length was shorter (21.1 ± 5.3 vs. 25.3 ± 9.6 mm, p<0.002) in group I.Two-year MACE were not different in the two groups (8.7%vs.10.0%, p=0.789). The incidences of cardiac death (0%vs.0%, p=1.000), MI (1.6%vs.6.7%, p=0.085), TLR(8.7% vs. 10.0%, p=0.789) and ST (0% vs. 0%, p=1000). DEB demonstrated comparable risk reduction for MACEs compared with DES in patients with ISR during two-year follow-up. DEB might be good alternative for the treatment of ISR in patients with ISR

충남 서북부지역의 개발 잠재력 분석 : 아산시를 중심으로

배성의,박동진,윤준상,황인극,최승철 공주대학교산업개발연구소 2000 産業開發硏究 Vol.8 No.-

This study was purpose for develop potential analysis of Chungnam north-west area and propose to regional development strategy. To arrived at a result for develop direction of Chungnam north-west area, Asan city will be development of central city for Asan bay, new indusrial city, tourist industrial city and ecological city.

저항성 스트립의 전자파 산란 패턴 제어에 관한 연구

박의준,최종인 金烏工科大學校 1998 論文集 Vol.19 No.-

A mixed potential integral equation(MPIE) for the induced current on a cylindrical perfect conductor with arbitrary thin cross-section is considered. The equation is applied to a strip for control of scattering field. The control is carried out by prediction of the current distribution for a prescribed pattern and than by extraction of resistance distribution on the strip using the relationship of each distribution which is established by physical optics. Examples of an efficient control is given with the appropriate optimization process for the nonuniform distribution functions.

분산 데이터 베이스 시스템에서의 충돌 그래프분석 기법에 관한 연구

박종원,최의인 충남대학교 자연과학연구소 1989 忠南科學硏究誌 Vol.16 No.1

The CGA(Conflict Graph Analysis) technique is used for preanalyzing of transaction when we design a data base. The CGA technique is mainly concerned with the design and implementation of a tool for this preanalysis operation. This technique classify's specification of transaction on classes, checks the conflict among them, and selects appropriate protocols for each pair of transaction classes.

Laparoscopic internal fixation is a viable alternative option for continuous ambulatory peritoneal dialysis catheter insertion

In Eui Bae,Woo Kyung Chung,Sang Tae Choi,Jinmo Kang 대한외과학회 2012 Annals of Surgical Treatment and Research(ASRT) Vol.83 No.6

Purpose: One of the major drawbacks of peritoneal dialysis (PD) is catheter migration and dysfunction. Preventing catheter migration is one of the main concerns. We compared laparoscopic internal fixation method with open surgical method for catheter migration rates. Methods: From January 2008 to August 2009, PD catheters were inserted by laparoscopic fixation (LF) method in 22 patients and by open surgery (OS) in 32 patients. Clinical data were reviewed retrospectively. The frequency of migration, peritonitis, and other complications were compared. Catheter and patient survival rates were also compared. Results: The mean age and sex ratio were not different between groups. Mean follow-up duration was 29.1 months in LF group and 26.1 months in OS group. More patients in LF group (27.3%) had history of laparotomy than in OS group (3.1%) (P = 0.01). The mean operation time was significantly longer in LF group (101.6 ± 30.4 minutes) than in OS group (72.4 ± 26.03 minutes) (P = 0.00). The cumulative incidence of catheter migration was 65.6% in OS group and 13.6% in LF group (P = 0.00). Migration-free catheter survival was higher in LF group (P = 0.001). There were no differences in complication rates between groups. Overall catheter survival was similar (P = 0.93). Patient survival rate at 2 years was not different (P= 0.13). Conclusion: Laparoscopic internal fixation of continuous ambulatory peritoneal dialysis catheter significantly reduces migration rates without any addition of complications. Also, laparoscopic technique did not incur patient morbidity or mortality despite the requirement for general endotracheal anesthesia and longer operation time. Therefore, internal fixation can be afforded safely in patients with previous abdominal surgery as either a salvage or preventive measure in patients with repeated catheter migration.