Bulk-Si와 PD-SOI에 형성된 SiGe p-MOSFET의 전기적 특성의 비교

최상식,최아람,김재연,양전욱,한태현,조덕호,황용우,심규환,Choi, Sang-Sik,Choi, A-Ram,Kim, Jae-Yeon,Yang, Jeon-Wook,Han, Tae-Hyun,Cho, Deok-Ho,Hwang, Yong-Woo,Shim, Kyu-Hwan 한국전기전자재료학회 2007 전기전자재료학회논문지 Vol.20 No.6

This paper has demonstrated the electrical properties of SiGe pMOSFETs fabricated on both bulk-Si and PD SOI substrates. Two principal merits, the mobility increase in strained-SiGe channel and the parasitic capacitance reduction of SOI isolation, resulted in improvements in device performance. It was observed that the SiGe PD SOI could alleviate the floating body effect, and consequently DIBL was as low as 10 mV/V. The cut-off frequency of device fabricated on PD SOI substrate was roughly doubled in comparison with SiGe bulk: from 6.7 GHz to 11.3 GHz. These experimental result suggests that the SiGe PD SOI pMOSFET is a promising option to drive CMOS to enhance performance with its increased operation frequency for high speed and low noise applications.

채널구조와 바이어스 조건에 따른 Si_0.8Ge_0.2 pMOSFET의 저주파잡음 특성

최상식,양현덕,김상훈,송영주,이내응,송종인,심규환,Choi Sang-Sik,Yang Hun-Duk,Kim Sang-Hoon,Song Young-Joo,Lee Nae-Eung,Song Jong-In,Shim Kyu-Hwan 한국전기전자재료학회 2006 전기전자재료학회논문지 Vol.19 No.1

High performance $Si_{0.8}Ge_{0.2}$ heterostructure metal-oxide-semiconductor field effect transistors (MOSFETs) were fabricated using well-controlled delta-doping of boron and $Si_{0.8}Ge_{0.2}$/Si heterostructure epitaxal layers grown by reduced pressure chemical vapor deposition. In this paper, we report 1/f noise characteristics of the SiGe pMOSFETs measured under various bias conditions of the gate and drain voltages changing in linear operation regions. From the noise spectral density, we found that the gate and drain voltage dependence of the noise represented same features, as usually scaled with $f^{-1}$ However, 1/f noise was found to be much lower in the device with boron delta-doped layer, by a factor of $10^{-1}_10^{-2}$ in comparison with the device fabricated without delta-doped layer. 1/f noise property of delta-doped device looks important because the device may replace bipolar transistors most commonly embedded in high-frequency oscillator circuits.

증례보고 : 복식 자궁절제술 후 발생한 편측 하지마비

최상식 ( Sang Sik Choi ),노영진 ( Young Jin Ro ),도상환 ( Sang Hwan Do ) 대한마취과학회 2003 Korean Journal of Anesthesiology Vol.45 No.5

신종 플루 폐렴으로 입원한 환자들에서 주요 합병증 발생과 관련된 인자

최상식 ( Sang Sik Choi ),김원영 ( Won Young Kim ),김성한 ( Sung Han Kim ),홍상범 ( Sang Bum Hong ),임채만 ( Chae Man Lim ),고윤석 ( Youn Suck Koh ),김원 ( Won Kim ),임경수 ( Kyung Su Lim ) 대한결핵 및 호흡기학회 2010 Tuberculosis and Respiratory Diseases Vol.68 No.3

Background: To date, there are few data on the risk factors for severe cases and deaths associated with the 2009 pandemic H1N1 influenza A. Here, we describe the clinical and epidemiologic characteristics of patients hospitalized for pneumonia and identify those factors associated with the development of major complications (MC). Methods: We reviewed the medical records of 41 cases of pneumonia admitted to a university-affiliated tertiary hospital between Aug 26 and Dec 10, 2009, and who had confirmed H1N1 influenza A based on real-time reverse transcriptase-polymerase-chain-reaction assay. There were 7,962 patients that fit these criteria. We compared the clinical features and demographic characteristics of patients who developed MC to with those who did not develop MC. Results: During the study period, 10 patients developed MC (required admission to the intensive care unit, n=10; required ventilator therapy, n=6; death, n=4). Patients with MC were significantly older than those without MC and more frequently had underlying medical conditions (90.0% vs 41.9%, p-value <0.01). In the patients with developed MC, the median PaO2/FiO2 ratio of 230.0 (145.0∼347.3) at admission and pneumonia severity index (PSI) score of 141.5 (88.3∼158.5) were higher than patients without MC. However, no differences were observed in laboratory findings or in viral shedding between the 2 groups. Conclusion: In hospitalized pneumonia patients of 2009 H1N1 influenza, old age, a history of malignancy, initial hypoxemia, PaO2/FiO2 ratio, and PSI score appear to be risk factor significantly related to developing MC. These findings might be the basis to influence strategies for admitting patients to an intensive or intermediate care unit and for pre-emptive antiviral therapy.

TV 프로그램 <한끼줍쇼>에 나타난 음식 문화와 정서

최상식(Choi Sang Sik) 한국컴퓨터정보학회 2017 한국컴퓨터정보학회 학술발표논문집 Vol.25 No.2

본 논문에서는 TV 프로그램 <한끼줍쇼>를 통해 보여주고자 한 한국인의 정서, 문화, 음식을 이야기하고자 한다. 한국 사회는 그동안 급격한 산업화의 영향으로 도시화가 빠르게 진행되어 왔다. 그로 인해 현대인의 모습은 컴퓨터와 모바일 폰을 친구 삼아 지내거나 식사시간을 넘겨서 혼자 식사를 해결하는 등 단출하고 분주한 생활을 보내고 있다. 이제는 예전처럼 단란하게 가족끼리 저녁을 먹으며 즐겁게 얘기 나누는 것이 이제는 흔치 않은 풍경이 되어 버렸다. 앞으로 4차 산업으로 나아가는 시점에서 한국 사회는 개인주의, 소외된 삶이 가속화될 것이다. 이 시점에서 우리 가족과 이웃을 돌아보며 무엇이 더 소중한지를 자 한다.

대상포진 후 어깨마비

최상식 ( Sang Sik Choi ),조주연 ( Ju Yeon Joh ),서명신 ( Myung Sin Seo ),이평복 ( Pyung Bok Lee ),오용석 ( Yong Seok Oh ),임석진 ( Seok Jin Lim ) 대한통증학회 2004 The Korean Journal of Pain Vol.17 No.1

Bottom 컬렉터와 단일 금속층 구조로 설계된 SiGe HBT의 전기적 특성

최아람,최상식,김준식,윤석남,김상훈,심규환,Choi, A-Ram,Choi, Sang-Sik,Kim, Jun-Sik,Yoon, Seok-Nam,Kim, Sang-Hoon,Shim, Kyu-Hwan 한국전기전자재료학회 2007 전기전자재료학회논문지 Vol.20 No.8

This paper presents the electrical properties of SiGe HBTs designed with bottom collector and single metal layer structure for RF power amplifier. Base layer was formed with graded-SiGe/Si structures and the collector place to the bottom of the device. Bottom collector and single metal layer structures could significantly simplify the fabrication process. We studied about the influence of SiGe base thickness, number of emitter fingers and temperature dependence $(<200^{\circ}C)$ on electrical properties. The feasible application in $1{\sim}2GHz$ frequency from measured data $BV_{CEO}{\sim}10V,\;f_T{\sim}14GHz,\;{\beta}{\simeq}110,\;NF{\sim}1dB$ using packaged SiGe HBTs. We will discuss the temperature dependent current flow through the e-b, b-c junctions to understand stability and performance of the device.

흔들림 보정을 통한 고해상 사이드스캔소나의 데이터 관리기법 연구

이종화,김영석,박철,최상식,이흥수,Yi, Jong-Hwa,Kim, Young-Seok,Park, Chul,Choi, Sang-Sik,Lee, Heung-Su 한국구조물진단유지관리공학회 2017 한국구조물진단유지관리공학회 논문집 Vol.21 No.5

기존의 예인식으로 운용하는 사이드스캔소나의 경우 조사 시 사용자가 원하는 단면 조사에 어려움이 있어 수중구조물 전동 지그가 개발되었지만, 전동지그를 사용한 음파촬영방법의 경우 보트와 소나가 일체 거동하기 때문에 파랑에 의한 보트 롤링현상, 보트운전자의 운용미숙 등으로 인한 음파영상의 흔들림발생 등, 작업환경에 따른 여러 가지 문제로 인하여 데이터의 왜곡이 발생하였다. 따라서 본 연구에서는 기존 사이드스캔소나의 수중조사를 위한 장비운용 시 발생하는 영상의 흔들림을 해결하기 위해, 흔들림 보정센서를 부착하고 흔들림 보정 알고리즘을 개발하여 흔들림보정이 가능하도록 프로그램을 보완하였다. 또한, 소나 데이터 해상도의 향상 정도를 검증하기 위하여, 현장조사를 통해 흔들림 보정 전 후 음파영상을 수집하고 손상 의심부에 잠수사를 투입하여 실제 손상길이 및 수심을 측정하여 취득한 음파영상 데이터의 분석을 수행하였다. 본 연구는 향후 사이드스캔소나를 활용한 구조물의 수중부 및 하상면 음파영상 촬영기법의 발전에 기여할 것으로 판단된다. In the case of the side scan sonar operated by the towing method, the underwater structure electric jig was developed because there is a difficulty in the cross-sectional survey that the user wants when conducting the survey. However, in the case of the sound wave photographing method using the electric jig, since the boat and the sonar behaves as one body, data distortion has occurred due to various problems according to working environment, such as, the rolling phenomenon of the boat due to the wave and the fluctuation of the sonic image due to the inoperability of the boat driver. Therefore, in order to solve the image blurring caused by the operation of the equipment for underwater survey of the existing side scan sonar, in this research, the program was supplemented to enable the shake correction by attaching the shake correction sensor and developing the shake correction algorithm. In order to verify the improvement of the sonar data resolution, the sonic images before and after the shake correction were collected through on-site investigation and the analysis of the sonic image data acquired by a diver measuring the actual damage length and depth. This study is expected to contribute to the development of sonar imaging technique of the underwater surface of the structure and bed surface of the sea or a river using the side scan sonar in the future.

고강도 콘크리트 전단벽의 전단강도

윤현도(Yun Hyun-Do),최상식(Choi Chang-Sik) 대한건축학회 2003 大韓建築學會論文集 : 構造系 Vol.19 No.5

Provisions for ACI 318-02, NZS 3101, and AIJ guideline pertaining to shear design of shear walls evaluated the applicability of high-strength, more than 41MPa, concrete shear walls subjected to lateral loads. Results of 73 tests of reinforced concrete shear walls were reviewed. Evaluation of test results conducted in Korea, England, America, Japan, and Australia for low-aspect ratio walls indicates that the nominal unit shear strength(ψ=1.0) calculated using the provisions of ACI and NZS does not represent the observed shear strength well. Especially, AIJ guideline is found to overestimate the shear strength of other walls except Japanese tests. Based on the limited database considered in this study, A reasonable lower bound to the shear strength of high-strength concrete shear walls is found to be 0.4 f cu ㎫. Similar to that of normal strength concrete walls, the rate of increase of the measured shear strength with ρ n?f y is less that 1.0. Therefore, the rate of increase of shear strength attributable to the web reinforcement in shear walls appears to be overestimated by the modified truss analogy.

CEO의 환경친화적 성향이 신제품 개발역량과 성과에 미치는 영향

이홍배(Lee, Hong-Bae),최상식(Choi, Sang-Sik) 한국의사결정학회 2013 의사결정학연구 Vol.21 No.2

환경 문제가 중요한 전략적 과제로 등장한 가운데 그린시장의 새로운 변화에 적극적으로 대처해 나가는 CEO의 전략적 성향을 CEO의 환경친화적 성향으로 설정하여 자신들이 보유하고 있는 역량을 토대로 경쟁우위를 획득해 나가는 과정을 파악하고자 하였다. 분석결과, 그린시장 환경의 변화가 상대적으로 큰 기업일수록 CEO의 환경친화적 성향이 더 높게 나타났다. 그리고 환경 거래적 성향의 CEO보다는 환경 변혁적 성향의 CEO가 재무 및 환경성과에 더 큰 영향력을 미치고 있음을 발견하였다. 이러한 결과는 위기상황이나 사회적 변화가 일어나고 있는 시기에 변혁적 리더십이 효과를 발휘할 가능성이 높다고 한 Bass(1989)의 연구를 지지하고 있다. 한편, Baron and Kenny(1986)의 논리에 따라 신제품개발 역량의 완전 매개적 특성을 발견하였다. 환경 변화를 신제품개발 역량으로 흡수하여 대처해 나가는 자원준거이론을 뒷받침하는 결과라고 판단할 수 있다. 끝으로, 그린시장 환경 수준의 조절효과가 유의함을 확인하였다. The purpose of this study is to examine the effect of CEO’s Eco-friendly leadership on the new product innovation(NPI) capabilities and the performance (financial and environmental performance) in the manufacturing industry, and also the moderating effects of green-market turbulence. For these purposes, we conceptualized and measured the CEO’s eco-friendly leadership as the modified concepts of the environmental transformational/ transactional leadership, and developed the covariance structural model which consists of several constructs. The results of this study can be summarized as follows: First, we classified two groups, the high and low level group of the environmental change through the cluster analysis. The high group has the more the CEO’s eco-friendly characteristics than the low. Second, in a good-fitting structural model which consists of five constructs, environmental transformational/transactional leadership has a positive effect on the performance. Third, we found the moderating effect of the green-market turbulence on the CEO’s eco-friendly leadership–NPI capabilities–performance path in the structural model. The higher the level of the green-market turbulence, the more strength of the mediating effect of the NPI capabilities. It is implied that a CEO’s eco-friendly leadership will strengthen the unique and specific NPI by the environmental transformational/transactional leadership to be cope with the environment crisis.