환경경영이 경영성과에 미치는 영향에 관한 연구

강민석,최현석,박병춘,Kang, Min-Seok,Choi, Hyun-Seok,Park, Byung-Chun 한국데이터정보과학회 2011 한국데이터정보과학회지 Vol.22 No.3

본 연구는 공분산 구조방정식 분석기법을 이용하여 환경경영전략, 환경경영시스템, 환경경영활동, 환경경영성과 간의 구조 관계와 상호 영향의 정도를 실증적 자료를 통해 규명하는 데 목적이 있다. 특히 환경경영전략 유형에 따라 이들 요소들 간의 구조 및 영향이 어떻게 달라지는지 규명하는데 연구의 초점을 둔다. 적극형 환경전략유형의 경우 환경경영시스템, 환경경영활동, 환경경영성과 모두에 정 (+)의 유의한 영향을 주었다. 그러나 소극형 환경전략유형의 경우 환경경영시스템, 환경경영활동에는 유의한 영향을 주었으나, 환경경영성과에는 유의한 영향을 미치지 못하였다. This study is to empirically investigate structural relations and the degree of effects among environmental strategy, environmental management system, environmental activities, and firm performance by using structural equation modelling. In particular, we focus on examining how the structure and the effect vary according to the type of environmental strategies. In this study, environmental strategies are classified as "passive type" and "active type" by the cluster analysis, which are used for developing two different research models. For firms employing active environmental strategy, the environmental strategy has a positive effect on all of environmental management system, environmental activities, and firm performance. For firms employing passive environmental strategy, the environmental strategy has a positive effect on both of environmental management system and environmental activities, while it does not have a statistically significant effect on firm performance. The study empirically supports that the active environmental management will result in a positive firm performance.

Mixed-mode 시뮬레이션을 이용한 SiC DMOSFETs의 스위칭 특성 분석

강민석,최창용,방욱,김상철,김남균,구상모,Kang, Min-Seok,Choi, Chang-Yong,Bang, Wook,Kim, Sang-Chul,Kim, Nam-Kyun,Koo, Sang-Mo 한국전기전자재료학회 2009 전기전자재료학회논문지 Vol.22 No.9

SiC power device possesses attractive features, such as high breakdown voltage, high-speed switching capability, and high temperature operation. In general, device design has a significant effect on the switching characteristics, In this paper, we demonstrated that the switching performance of DMOSFETs are dependent on the with Channel length ($L_{channel}$) and Current Spreading Layer thickness ($T_{CSL}$) by using 2-D Mixed-mode simulations. The 4H-SiC DMOSFETs with a JFET region designed to block 800 V were optimized for minimum loss by adjusting the parameters of the JFET region, CSL, and epilayer. It is found that improvement of switching speed in 4H-SiC DMOSFETs is essential to reduce the gate-source capacitance and channel resistance. Therefore, accurate modeling of the operating conditions are essential for the optimizatin of superior switching performance.

복잡지형의 온대산림에서 에디 공분산으로 관측된 CO₂ 플럭스의 야간 자료 보정에 관하여

강민석,김준,김현석,빈두 말라 타쿠리,천정화,Kang, Minseok,Kim, Joon,Kim, Hyun-Seok,Thakuri, Bindu Malla,Chun, Jung-Hwa 한국농림기상학회 2014 한국농림기상학회지 Vol.16 No.3

복잡지형에서의 에디 공분산 방법을 이용한 플럭스 관측에 있어서 가장 중요하면서도 어려운 문제 중에 하나가 야간 이산화탄소($CO_2$) 플럭스 자료 보정이다. 본 연구에서는 복잡산림지형에 위치한 두 KoFlux 관측지(광릉의 활엽수림과 침엽수림 관측지, GDK와 GCK)의 2009년도 플럭스 타워 자료에 대표적인 야간 자료 보정 방법인 마찰속도 보정 방법, 광 반응 곡선 보정 방법, 이류를 고려한 반 고셀 보정 방법을 적용한 결과를 평가하였다. 계산된 $CO_2$ 플럭스(생태계호흡, 총일차생산, 순생태계교환)는 방법에 따라 그 크기와 계절변동에 차이를 보였는데, 그 차이는 관측지 별로 다르게 나타났다. 각 방법에서 나온 결과들을 선행연구에서 보고된 결과들과의 비교와 함께, 기상학적인 접근뿐만 아니라 생태학적인 접근을 통해 검증하였다. 검증 결과, 이러한 차이의 원인은 야간 자료 보정 과정에서 선별된 자료의 일부가 이미 배수류에 의한 $CO_2$ 이류의 영향을 받았기 때문인 것으로 추측된다. GDK의 광 반응 곡선 방법의 결과를 제외한 나머지 $CO_2$ 플럭스 결과들은 아시아의 다양한 생태계에서 보고된 값들의 범위에 포함되었다. 본 연구는 현재 배포된 플럭스 자료들은 개선의 여지가 있으며, 최신 자료의 올바른 사용을 위한 자료 사용자와 자료 생산자 간의 소통의 중요성을 상기시켜 준다. Nighttime correction of $CO_2$ flux is one of the most important and challenging tasks in eddy covariance measurements over a complex mountainous terrain. In this study, we have scrutinized the quality and the credibility of the $CO_2$ flux datasets which were produced by employing three different methods of nighttime correction, i.e., (1) friction velocity ($u^*$) correction, (2) light response curve (LRC) correction, and (3) advection-based van Gorsel (VG) correction. The whole year datasets used in our analysis were collected at the two KoFlux tower sites (i.e., GDK deciduous forest site at the upper hill and GCK coniferous forest site at the lower hill) located in the valley of Gwangneung National Arboretum in central Korea. The resultant magnitudes and patterns of ecosystem respiration ($R_E$), gross primary productivity (GPP), and net ecosystem exchange (NEE) of $CO_2$ showed marked differences among the datasets produced with three different correction methods, which were also site-specific. The examination from micrometeorological and ecological perspectives suggests that the major cause of some inconsistency seems to be associated with the advection of $CO_2$ along the sloping terrain and the inappropriate selection of the correction data that might have been already affected by advective flows. The comparison with the results from other studies indicated that the overall characteristics of the corrected $CO_2$ fluxes at GDK and GCK (except those with LRC correction) were well within the ranges reported in the literature for various ecosystems in East Asia in similar latitudes. However, our study also implies that there will be always a room for further improvement in the present datasets. Therefore, caution must be exercised for the data users in order to properly use the updated version of datasets through transparent, open and participatory communication with data producers.

IEEE 802.160에서 상향링크 VoIP 스케줄링 알고리즘 방식 연구

강민석,장재신,Kang, Min-Seok,Jang, Jae-Shin 한국시뮬레이션학회 2006 한국시뮬레이션학회 논문지 Vol.15 No.3

이동통신이 생활화됨에 따라 유선망에서 사용하고 있는 초고속 인터넷을 무선망에서도 사용하고자 하는 욕구가 증가하게 되었으며 기존 WLAN(Wireless Local Area Network)시스템에서 커버리지 제한 문제와 단말의 이동성을 제공해주지 못하는 단점을 보안하고, 이동통신 시스템에서 고가의 통신요금 문제를 해결하기 위해 WMAN(Wireless Metropolitan Area Network) 표준이 새롭게 등장하였다. IEEE 802.16 계열의 WMAN 표준은 다양한 PHY 계층(SC, SCa, OFDM OFDMA)을 수용할 수 있는 MAC 표준과 단말의 이동성을 지원해주는 MAC 표준을 규정하고 있어서 차기 무선 인터넷에서 중요한 위치를 차지 할 것으로 보인다. 본 논문에서는 VoIP 서비스를 IEEE 802.16d에서 규정하고 있는 4가지 서비스 중 UGS 서비스 형태로 효과적으로 스케줄링 할 수 있는 상향링크 ON/OFF Grant 알고리즘을 제안하고 제안된 알고리즘이 규격에서 정의하는 기존의 방식과 참고문헌의 방식을 이용하여 서비스하는 것보다 VoIP 사용자의 평균 지연시간과 상향링크 자원 활용 측면에서 우수함을 NS-2 시뮬레이션을 통해 제시한다. With the growth of the internet, the number of wireless internet users has increased continuously up to date. However, mobile communications could not support high speed transmission rate with cheap communication fee and wireless LAN has problems in providing terminal mobility and wide area connectivity, respectively. So the WMAN standard has been newly designed to make up for these limits. The initial 802.16 specification effectively offers a solution for providing fixed users with high speed wireless communication but it does not offer terminal mobility. So the 802.16d and 802.16e have been developed as the next generation solution that can support various PHY layer (SC, SCa, OFDM, OFDMA) and offer the terminal mobility. In this paper, we propose an effective uplink scheduling algorithm for VoIP with using UGS, and we show that our proposed algorithm is superior in view of average delay and management of uplink bandwidth to conventional rtPS algorithm and the scheme in reference, with using NS-2 network simulator.

혈관용해 레이저를 이용한 후두미세수술 최신 지견

강민석,임재열,Kang, Min Seok,Lim, Jae-Yol 대한후두음성언어의학회 2021 대한후두음성언어의학회지 Vol.32 No.2

There are several lasers available for office-based or suspension microlaryngoscopy laser procedures in the treatment of laryngeal diseases. Each has advantages and disadvantages given the depth of penetration per unit of power, absorption in water, spectral absorption characteristics, mode of delivery, safety, and cost. It is important to note that while the proper selection of indication of treatment based on a laser wavelength is critical, of equal importance is selecting the appropriate power setting, focal length (or spot size), and time of exposure. The photoangiolytic lasers precisely target hemoglobin within the microcirculation of the highly vascularized tissue and may have better hemostatic effects and preservation of surrounding normal tissue than the CO₂ laser. Although the choice of laser is purely theoretical and cannot be accurately concluded which parameters of laser (wattage and pulse width) were best to use, photoangiolytic laser surgery is safe and effective for specific laryngeal lesions. In this review, indications for photoangiolytic laser procedures for various laryngeal diseases, laser settings and surgical techniques for specific laryngeal lesions including sulcus vocalis, laryngeal dysplasia, and recurrent respiratory papillomatosis will be introduced. Pros and cons of in-office laser surgery using photoangiolytic laser and flexible CO₂ laser will also be addressed.

앙상블 기법을 이용한 안동댐 유입량 예측

강민석,유명수,이재응,Kang, Min Suk,Yu, Myungsu,Yi, Jaeeung 대한토목학회 2014 대한토목학회논문집 Vol.34 No.3

본 연구에서는 앙상블유량예측기법과 SWAT 모형을 이용하여 안동댐의 2011년 7월~9월의 각 댐유입량 예측을 실행하였으며 월별 및 순별 분석을 수행하였다. 또한 정확한 분석을 위해 기상청의 월별 및 순별 강우예보자료를 이용한 가중값 부여방법을 사용하였다. 분석 결과 기상청에서 발표한 강우 예측 구간이 실제 강우 구간과 동일하면 PDF-Ratio 가중값 부여방법이 가장 높은 정확성을 보이며, 과거 강우발생 구간 통계 중 높은 구간이 실제 강우 구간과 동일하다면 수정 PDF-Ratio 가중값 부여방법이 가장 높은 정확성을 보였다. 이는 기상청 예측이 맞지 않은 경우에도 과거 강우발생 구간의 빈도에 따라 정확성을 높일 수 있을 것으로 판단된다. 반대로 기상청의 예측이 실제와 다르면서 과거 강우발생 구간 통계에서도 낮은 구간의 강우가 발생하면 균일 가중값 부여방법의 정확성이 가장 높게 분석되었다. In this study, Andong Reservoir monthly and ten days inflows from July 2011 to September 2011 are predicted using SWAT model and ensemble technique. The weight method using monthly and ten days rainfall forecasts from Korea Meteorological Administration is applied for accurate analysis. If the rainfall prediction announced by Korea Meteorological Administration is close to the actual rainfall, the PDF-Ratio Method shows the best result. If the past high rainfall occurrence is close to the actual rainfall, the modified PDF-Ratio method shows the best result. This method can improve the prediction accuracy even though the Korea Meteorological Administration forecast is not accurate. On the contrary, if Korea Meteorological Administration forecast is different from the actual rainfall and the past rainfall occurrence statistics of lower section, the uniform method shows the best result.

4H-SiC DMOSFETs의 계면 전하 밀도에 따른 스위칭 특성 분석

강민석,문경숙,구상모,Kang, Min-Seok,Moon, Kyoung-Sook,Koo, Sang-Mo 한국전기전자재료학회 2010 전기전자재료학회논문지 Vol.23 No.6

SiC power device possesses attractive features, such as high breakdown voltage, high-speed switching capability, and high temperature operation. In general, device design has a significant effect on the switching characteristics. In this work, we report the effect of the interface states ($Q_f$) on the transient characteristics of SiC DMOSFETs. The key design parameters for SiC DMOSFETs have been optimized by using a physics-based two-dimensional (2-D) mixed device and circuit simulator by Silvaco Inc. When the $SiO_2$/SiC interface charge decreases, power losses and switching time also decrease, primarily due to the lowered channel mobilities. High density interface states can result in increased carrier trapping, or more recombination centers or scattering sites. Therefore, the quality of $SiO_2$/SiC interfaces has a important effect on both the static and transient properties of SiC MOSFET devices.

SF₆/O₂ 혼합가스에 의한 실리콘 웨이퍼의 표면 텍스쳐링 특성

강민석,주성재,구상모,Kang, Min-Seok,Joo, Sung-Jae,Koo, Sang-Mo 한국전기전자재료학회 2012 전기전자재료학회논문지 Vol.25 No.5

The optical losses associated with the reflectance of incident radiation are among the most important factors limiting the efficiency of a solar cell. Therefore, photovoltaic cells normally require special surface structures or materials, which can reduce reflectance. In this study, nano-scale textured structures with anti-reflection properties were successfully formed on silicon. The surface of sicon wafer was etched by the inductively coupled plasma process using the gaseous mixture of $SF_6+O_2$. We demonstrate that the reflection characteristic has significantly reduced by ~0% compared with the flat surface. As a result, the power efficiency $P_{max}$ of the nano-scale textured silicon solar cell were enhanced up to 20%, which can be ascribed primarily to the improved light trapping in the proposed nano-scale texturing.

한국 플럭스 관측망의 과거, 현재와 미래

강민석,권효정,김준,김현석,류영렬,이승재,최태진,Kang, Minseok,Kwon, Hyojung,Kim, Joon,Kim, Hyun-Seok,Ryu, Youngryel,Lee, Seung-Jae,Choi, Taejin 한국농림기상학회 2018 한국농림기상학회지 Vol.20 No.1

제조 추출물의 혈전 용해 활성에 대한 실험적 연구

강민석,김신,초재승,김효수,김일환,박혜선,서은희,임치혜,Kang, Min-Seok,Kim, Shin,Cho, Jae-Seung,Kim, Hyo-Soo,Kim, Il-Hwan,Park, Hye-Sun,Seo, Eun-Hee,Yim, Chi-Hye 사상체질의학회 2007 사상체질의학회지 Vol.19 No.1

1. Objectives This study was performed to find the activities and characteristics of purified thrombolytic enzymes from Holotrichia extracts. 2. Methods In the first time, a coarse enzyme fluid was made by using the freedried Holotrichia extracts. After manufacturing total soluble proteins and purifing enzymes, it was evauluated the activities and characteristics of this enzyme's dissolving capability to fibrin and thrombus. This study was taken using azocasein assay, fibrin-plate method, native-PAGE and fibrin zymography. 3. Results A soluble proteins were efficiently extracted form freezedried Holotrichia extracts. And, this purified enzyme had a ten times fibrinolytic capability compare with ustulation Holotrichia sample. In native PAGE and fibrin zymography, Holotrichia extracts showed the respectable fibrinolytic activity. Also, It had higher thrombolytic activities compared with general thrombolytic enzyme 'plasmin'. In experiment of various protease inhibitors of the purified enzyme from Holotrichia extracts on the azocaseinolytic activity, the enzyme was strongly inhibited by EDTA ${\cdot}$ EGTA, and weakly by APMSF ${\cdot}$ PMSF ${\cdot}$ TPCK. 4. Conclusion Holotrichia extracts has the thrombolytic activities, and it will operate directly th fibrin-clot and thrombus.