• Journal of Chest Surgery
• /
• v.28 no.12
• /
• pp.1192-1196
• /
• 1995

As reported in the literature, extraskeletal mesenchymal chondrosarcoma is a rare malignant tumor of soft tissue, and it has a unique, distinctive histologic picture and poor prognosis.The common sites are the orbit, the cranial dura mater, the neck, the thigh, the leg, the chest wall, and the retroperitoneum. Radical excision of the tumor seems to be the primary treatment.We report experience with a very rare case of extraskeletal mesenchymal chondrosarcoma in the posterior mediastinum.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2002.11a
• /
• pp.271-272
• /
• 2002

현재 우리나라에서는 PM10이 분진 측정 항목으로 대변되고 있으나 미세 영역에 해당하는 PM2.5나 PM1.0의 범위의 측정에 관심이 집중되고 있다. 미세 영역의 분진은 많은 양이 호흡기에 침착되거나 시정의 감쇄를 야기 시킨다 (Eldering and Cass, 1996 : Anderson et al., 1992). 미국 National Ambient Air Quality Standard (NAAQS)는 1997년 PM2.5 항목의 추가를 공표하였다. (중략)

• Journal of Korea Water Resources Association
• /
• v.51 no.3
• /
• pp.247-261
• /
• 2018

The purpose of this study is to evaluate the groundwater level behavior of Geum river basin ($9,645.5km^2$) under future climate change scenario projection periods (2020s: 2010~2039, 2050s: 2040~2069, 2080s: 2070~2099) using SWAT (Soil and Water Assessment Tool). Before future evaluation, the SWAT was calibrated and validated using 11 years (2005~2015) daily multi-purpose dam inflow at 2 locations (DCD, YDD), ground water level data at 5 locations (JSJS, OCCS, BEMR, CASS, BYBY), and three years (2012~2015) daily multi-function weir inflow at 3 locations (SJW, GJW, BJW). For the two dam inflow and dam storage, the Nash-Sutcliffe efficiency (NSE) was 0.57~0.67 and 0.87~0.94, and the coefficient of determination ($R^2$) was 0.69~0.73 and 0.63~0.73 respectively. For the three weir inflow and storage, the NSE was 0.68~0.70 and 0.94~0.99, and the $R^2$ was 0.83~0.86 and 0.48~0.61 respectively. The average $R^2$ for groundwater level was from 0.53 to 0.61. Under the future temperature increase of $4.3^{\circ}C$ and precipitation increase of 6.9% in 2080s (2070~2099) based on the historical periods (1976~2005) from HadGEM3-RA RCP 8.5 scenario, the future groundwater level shows decrease of -13.0 cm, -5.0 cm, -9.0 cm at 3 upstream locations (JSJS, OCCS, BEMR) and increase of +3.0 cm, +1.0 cm at 2 downstream locations (CASS, BYBY) respectively. The future groundwater level was directly affected by the groundwater recharge by the future seasonal spatial variation of rainfall in the watershed.

• Research in Mathematical Education
• /
• v.13 no.1
• /
• pp.1-4
• /
• 2009

We are considering the discovery and the promotion of the talent from the viewpoint of education of talented children. The education that develops the talent is from "Individual needs for all children." Computer Algebra System (CAS) can be used as a new possibility in the education that develops the talent. We will need to take advantage of the research results from cognitive science. In order to fully utilize CASs in education, teaching methods that are based on cognitive science will be needed, and these are clearly different from those used in paper and pencil teaching.

• Proceedings of the KSME Conference
• /
• 2008.11a
• /
• pp.368-371
• /
• 2008

An extensometer system to measure strain and displacement of cylindrical fatigue specimen in a autoclave of high temperature and high pressure environment has been developed by KEPRI. The extensometer reads the displacement caused by fatigue loads at the target length of the specimen installed inside the autoclave. The performance of the extensometer were tested at 15MPa, $315^{\circ}C$ of a operating pressurized water reactor. Two LVDT's of magnet type were connected to the extensometer and used for converting the fatigue displacement to electronic signal. The device is being used for developing environmental fatigue curve of CF8M cast austenitic stainless steel (CASS) in the test condition of low cycle and low strain. This paper introduces the background and results of the development.

• Management Science and Financial Engineering
• /
• v.17 no.2
• /
• pp.1-21
• /
• 2011

This paper considers an integrated inventory-distribution system with a fleet of heterogeneous vehicles employed where a single warehouse distributes a single type of products to many spatially distributed retailers to satisfy their dynamic demands. The problem is to determine order planning at the warehouse, and also vehicle schedules and delivery quantities for the retailers with the objective of minimizing the sum of ordering cost at the warehouse, inventory holding cost at both the warehouse and retailers, and transportation cost. For the problem, we give a Mixed Integer Programming formulation and develop a Lagrangean heuristic procedure for computing lower and upper bounds on the optimal solution value. The Lagrangean dual problem of finding the best Lagrangrean lower bound is solved by subgradient optimization. Computational experiments on randomly generated test problems showed that the suggested algorithm gives relatively good solutions in a reasonable amount of computation time.

• Journal of the Korean institute of surface engineering
• /
• v.32 no.4
• /
• pp.521-530
• /
• 1999

The corrosion resistance and the hardness of the tin-nickel alloy deposits electroplated in pyrophosphate bath were invesitigated according to electrolysis conditions and microstructure of the alloy. The weight loss of alloy deposits increased with the Sn content of single phase (Ni-Sn) alloy showing the lowest weight loss in the alloy with 54∼57wt% Sn. On the other hand, the multiphase alloy with 35∼42wt% Sn showed the highest one. The CASS test result was consistent with that of immersion test, and was good agreement with the corrosion data of polarization measurements. The hardness of alloy deposits decreased with the increase of Sn ratio in bath due to the grain size increase of the alloy. However, it increased noticeably with decreasing current density in the bath condition of low Sn ratio (0.1)

• Proceedings of the Korea Society for Industrial Systems Conference
• /
• 2008.10b
• /
• pp.457-462
• /
• 2008

User perceptions toward information technology (IT) are crucial to successful implementation. The purpose of our study is to improve the understanding of the impact of social influences on different types of users' perceptions and adoption of IT. To do this our study refines and expands the operationalization of the social influence construct to include four components: "subjective norm", "image","visibility", "voluntariness". We use this to examine influences by type of user (knowledge worker versus university student) and IT (innovative versus mature). The key finding is that when knowledge workers consider adopting innovative IT they are sensitive to general perceptions of its usefulness. Our results have implications for management enquiry and practice.

• 한국항공운항학회:학술대회논문집
• /
• 2015.11a
• /
• pp.127-132
• /
• 2015

조직의 안전문화가 사고의 원인이 될 수 있다는 것이 알려지면서 안전문화의 개선과 정착의 중요성이 강조되고 있다. 우리나라는 항공법 제49조에 지정전문교육기관은 자체 안전관리시스템을 운영하도록 규정하고 있으며 관련 규정에는 조직의 안전문화를 조사하여 상태를 파악하고 발견된 문제점을 개선할 것을 권고하고 있다. 본 논문에서는 교통안전공단에서 개발한 축약형 CASS Scale을 사용하여 조종사양성 교육기관의 안전문화지수를 측정하였다. 측정결과 안전문화 평균치는 3.711로 나타났으며 하위지표의 측정결과는 직원 권한위임에 대한 평균값이 3.980으로 가장 높게 나타났고, 상벌체계에 대한 평균값이 3.309로 가장 낮게 나타났다. 서비스제공자는 이러한 측정 결과에 근거하여, 취약부분에 대한 개입전략을 수립, 적용함으로써 조직문화 향상에 도움을 줄 것으로 사료된다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.1519-1522
• /
• 2009

We describe a 32" liquid-crystal display (LCD) with multi-touch sensing capability by integrating IR detector arrays onto the LED backlight plate. A transparent light guide is placed in front of the display screen, with IR LEDs disposed at its edges and emitting IR light into the light guide, the light is trapped by total internal reflection within the light guide to be as touch-sensing light. A physical contact with the acrylic plate surface will stimulate some trapped light to be escaped from the light guide and pass through LCD panel to be detected by the IR detectors. The touch-sensing LCD with this configuration can locate simultaneous multiple touche points on the touchable surface.