Research on Powder Metallurgy Technology in Fusion Materials in China

Ge Chang-Chun,Zhou Zhang-Jian,Du Juan,Song Shu-Xiang 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

In the viewpoint of engineering, materials problem is a key problem, which determines whether the exploitation of fusion energy will be success. The most important class of fusion materials is plasma-facing materials (PFM). W, as high Z high melting-point metal is one of the most important candidate materials due to its high plasma erosion resistance. Improving the ductility of W and W based alloy, lowering its ductile-brittleness transition temperature for meeting the requirements of fusion application is an important task. In this paper, severalpowder meatllurgy methods of fabricating W and W based materials are being investigated.

합성개구레이더용 전방향 반사기의 설계

장지성 ( Ge Ba Chang ),양찬수 ( Chan Su Yang ),오이석 ( Yi Sok Oh ) 大韓遠隔探査學會 2007 大韓遠隔探査學會誌 Vol.23 No.6

본 연구에서는 합성개구레이더(synthetic aperture radar, SAR) 영상의 보정에 사용되고 있는 반사기(corner reflector, CR)를 이용하여 목표물의 식별과 인식을 위한 기초적인 연구를 실시하였다. 사각형 삼면 전파반사기를 기반으로 전방향(omni-directional) 반사기를 제작하였다. 여기서는 한 변의 길이가 15cm인 4-배열 사각형 삼면 전파반사기를 사용하여 C-밴드(주파수: 5.3 GHz) 의 편파별(VV, HH, VH, HV) RCS(radar cross section)특성을 해석하였다. 전파반사기는 대칭형이므로 방위각 180도 범위에 대해서 레이더 산란단면적 패턴을 측정하였다. VV편파의 경우 방위각에 따른 RCS값의 차이가 8dB정도로 다른 편파보다 전방향 특성이 더 좋은 것으로 확인되었고 방위각이 0˚(단면과 동일 방향)와 45˚(이웃하는 단면들의 중앙) 일 때, 가장 높은 RCS값을 보였다. 또한, 실험에서 얻어진 RCS값을 수치 해석 시뮬레이션과 이론적 계산과 비교를 실시한 결과, 서로 잘 일치하는 것으로 나왔다. Basic research is conducted to identify a target using corner reflectors which are commonly used in calibration of synthetic aperture radar (SAR) systems. At first, an omni-directional reflector is fabricated by combining four 15-cm rectangular trihedral corner reflectors. Then, its radar cross section (RCS) characteristics are measured at C-band (5.3 GHz) for vv-, hh-, hv-, and vh-polarizations at a range of horizontal angle, -90˚≤Φ≤90˚. The measured RCS angular variation of the omni-directional reflector is much smaller for vv-polarization than other polarizations, and the difference between the maximum and minimum RCSs for vv-polarization is about 8 dB. Peak RCS values are shown at 0˚ (normal to plates) and 45˚ (direction of bore sight). It is shown that the measurements agree quite well with numerical simulation and theoretical computation results.

서울 주거부문 에너지 소비량 저감 전략에 따른 효과 분석

정창헌(Cheong Chang-Heon),김지영(Kim Ji-Yoe),김석기(Kim Seok-Ge),김태연(Kim Tae-Yeo),이승복(Leigh Seung-Bok) 대한건축학회 2009 대한건축학회논문집 Vol.25 No.11

Energy efficiency in City is becoming a crucial issue in Korea. Seoul, the capital of Korea tries to reduce energy consumption and CO2 emission rate. Building energy consumption in Seoul is very high and construction of energy efficient building beome much more important than ever before. Therefore, appropriate establishment of building energy reduction strategy is very important. The Purpose of this study is to evaluate the residential building energy reduction scenarios and to give reasonable guidelines for residential building energy reduction strategy. This study performes following three procedure. First, analysis over the domestic building energy policy was performed. Second, we made several scenarios about energy consumption in domestic building field and evaluated each scenario. Third, analysis about each scenario was performed and several guidelines were determined. As a result, it is found that reduction of energy consumption in existing building is very important to effectively reduce energy consumption in domestic building in Seoul. In addition to this, energy reduction in residential building category is very hard than expected. Consequently energy reduction by changing citizen's life style to sustainable life style is strongly urged.

Patterns of care for patients with nasopharyngeal carcinoma (KROG 11-06) in South Korea

Sung, Soo Yoon,Kang, Min Kyu,Kay, Chul Seung,Keum, Ki Chang,Kim, Sung Hwan,Kim, Yeon-Sil,Kim, Won Taek,Kim, Ji-Yoon,Kim, Jin-Hee,Moon, Sung Ho,Ahn, Yong Chan,Oh, Young Taek,Wu, Hong-Gyun,Lee, Chang-Ge The Korean Society for Radiation Oncology 2015 Radiation Oncology Journal Vol.33 No.3

Purpose: To investigate the patterns of care for patients with nasopharyngeal carcinoma (NPC) in South Korea. Materials and Methods: A multi-institutional retrospective study was performed (Korean Radiation Oncology Group [KROG] 11-06) on a total of 1,445 patients from 15 institutions. Results: Of the 1,445 patients, more than half were stages III (39.9%) and IV (35.8%). In addition to patterns of care, we also investigated trends over time with the periods 1988-1993, 1994-2002, and 2003-2011. The frequencies of magnetic resonance imaging and positron emission tomography-computed tomography were markedly increased in the third period compared to previous 2 periods. Concurrent chemoradiation (CCRT) was performed on 894 patients (61.9%), neoadjuvant chemotherapy on 468 patients (32.4%), and adjuvant chemotherapy on 366 patients (25.3%). Of stage II-IV patients, CCRT performed on 78.8% in 2003-2011 compared to 15.0% in 1988-1993. For patients treated with CCRT, cisplatin was the most commonly used agent in 81.3% of patients. Over the periods of time, commonly used radiotherapy (RT) techniques were changed from 2-dimensional RT (1988-1993, 92.5%) to 3-dimensional RT (2003-2011, 35.5%) or intensity-modulated RT (IMRT; 2003-2011, 56.5%). Median RT doses given to primary tumors, high-risk lymphatics, and low-risk lymphatics were 70.0 Gy, 58.1 Gy, and 48.0 Gy, respectively. Adoption of IMRT increased the dose per fraction and escalated total radiation dose. Conclusion: Assessment of the patterns of care for NPC patients in South Korea demonstrated that management for NPC including diagnostic imaging, treatment regimen, RT techniques and dose schedule, advanced in accordance with the international guidelines.

Research Competition 5 : Transcriptional regulation in keratinocyte differentiation

( Chang Deok Kim ),( Seul Ki Lim ),( Ge Shi ),( Kyung Cheol Sohn ),( Dae Kyoung Choi ),( Jeung Hoon Lee ) 대한피부과학회 2015 대한피부과학회 학술발표대회집 Vol.67 No.2

C. R發振器의 多目的 利用

張鉉桂 釜山工業大學校 1969 論文集 Vol.9 No.-

Wien bridge를 이용한 소위 C.R.Oscillator는 그 제작이 간단하고 Condenser C와 Resistance R만의 결합으로 넓은 주파수 범위에 걸쳐서 안정도가 좋은 Oscillator가 된다. Electronics 측정기로서는 필수일 것이며 진동수 측정 파형, Amplifier의 성능, Impedance측정 등 광범하게 이용된다. 여기서는 과학교육을 중심으로 하는 용도에 관하여 연구하였다. (1) 음감에 의한 진동수의 대략치는 피아노음과 비교함으로서 음정의 진동수 혹은 파장측정 또한 가청 진동수가 어디까지인가? 초음파란 무엇인가? 오디오 진동수의 개인차, 공기 중에서의 음파의 감쇠도 더 나아가서 액체 중에서의 초음파의 방향성, 소리의 정상파, 간보 및 반사의 측정 등 진동에 관한 실험의 음원으로서의 이용을 연구하였다. (2) 저항과 콘덴서의 impedance 측정 및 용액의 전도도(conductivity) 측정을 생각하였다. 그래서 Bridge circuit를 구성시켜 평형점을 찾기 위하여 2단으로 증폭시켜 검출에 고가인 Ampere meter를 없애고 시중에서 쉽게 구할 수 있는 6E5(Magic eye)를 사용하였다. 사용이 간편하고 detector로서 operation이 빠른 이점이 있다. 이것을 써서 R.C 및 용액의 Conductivity를 구하였다. (3) Stroboscope로서의 역할을 하도록 시도하였다. 회전수의 측정, 모터의 Slipping, 진동체의 진동수 등 매우 중요한 용도가 있는데 여기서는 강력한 광을 내는 Stroboscope 전용의 방전관을 구할 수 없었기 때문에 염가인 Neon tube를 사용하였다. C.R.Oscillator로서 연속적으로 주파수를 바꿀 수 있기 때문에 이 출력을 네온관에 가하여 점멸시켰다. 이 광을 회전체에 비치면 같은 진동수이면 마치 정치하고 있는 것 같이 보이기 때문이다. 네온관이기 때문에 광이 약하여 어두운 곳에서 실험하지 않으면 안되지만 매우 유용한 것이었다.

Expression and functional role of Sox9 in keratinocyte differentiation

Ge Shi,Kyung Cheol Sohn,Dae Kyoung Choi,Young Lee,Chang Deok Kim,Young Joon Seo,Jeung Hoon Lee 한국피부장벽학회 2009 한국피부장벽학회지 Vol.11 No.2

Sox9 (SRY (sex determining region Y)-box 9) is an autosomal gene involved in the control of the male-determining pathway. It has been known that Sox9 is expressed in outer root sheath of hair follicle and exerts its action as an importance regulator in maintenance of stemness for hair cells. However, its expression and putative role in epidermal keratinocytes has not been well elucidated yet. In this study, we examined the expression and functional role of Sox9 in keratinocyte differentiation. Immunohistochemical staining showed that Sox9 is predominantly expressed in basal layer. Consistent with this result, Sox9 mRNA level was markedly decreased by the calcium treatment of cultured keratinocytes. And, Western blot also showed that the protein level for Sox9 was decreased by calcium in a temporal manner. To investigate its putative role, we made a recombinant adenovirus harboring the expression cassette for Sox9. Overexpression of Sox9 prevented calcium-induced loricin and involucrin expression. Consistent with, overexpression of Sox9 decreased the promoter activities of involucrin and loricrin. In addition, Sox9 overexpression resulted in significant down-regulation of the cell cycle-related genes p21. Interestingly, Sox9 expression was highly increased in several skin diseases such as psoriasis, BCC and SCC. Together, these results suggest that Sox9 is an important regulator for keratinocyte proliferation and differentiation, and may have related with many of skin diseases that are characterized by the hyperproliferative potential of keratinocytes.

Transcriptional Regulation in Keratinocyte Differentiation

( Chang Deok Kim ),( Seul Ki Lim ),( Ge Shi ),( Kyung Cheol Sohn ),( Dae Kyoung Choi ),( Jeung Hoon Lee ) 한국피부장벽학회 2014 한국피부장벽학회지 Vol.16 No.2

Terminal differentiation of skin keratinocytes, in which the transition from basal keratinocytes to corneocytes is occurred, is a complex process that requires the simultaneous activation and inactivation of a wide variety of genes that must be expressed at the correct time and in the correct location. A number of ubiquitous transcription factors, such as AP1, Sp1, and the AP2 family members, are involved in regulating keratinocyte gene expression and differentiation. Although the functional involvement of many transcription factors in keratinocyte differentiation has been known, however, it is not sufficient to understand the sophisticated regulatory mechanism underlying this process. In this study, additional transcription factors such as Sox9, PITX2 and Brn2 are discussed based on recent research results. When Sox9 was overexpressed, cell growth was enhanced while the expression of differentiation-related genes such as loricrin and involucrin was markedly decreased. In contrast, PITX2c overexpression led to increase of differentiation markers at both mRNA and protein levels. Similarly, Brn2 overexpression resulted in increased expression of the differentiation-related genes. These results indicate that keratinocyte differentiation is a dynamic process in which a variety of transcription factors are coordinately involved to balance the proliferation and differentiation.

Session 1 : What`s new in Skin Research ; Transcriptional Regulation in Keratinocyte Differentiation

( Chang Deok Kim ),( Seul Ki Lim ),( Ge Shi ),( Kyung Cheol Sohn ),( Dae Kyoung Choi ),( Jeung Hoon Lee ) 한국피부장벽학회 2014 한국피부장벽학회지 Vol.16 No.2

Terminal differentiation of skin keratinocytes, in which the transition from basal keratinocytes to corneocytes is occurred, is a complex process that requires the simultaneous activation and inactivation of a wide variety of genes that must be expressed at the correct time and in the correct location. A number of ubiquitous transcription factors, such as AP1, Sp1, and the AP2 family members, are involved in regulating keratinocyte gene expression and differentiation. Although the functional involvement of many transcription factors in keratinocyte differentiation has been known, however, it is not sufficient to understand the sophisticated regulatory mechanism underlying this process. In this study, additional transcription factors such as Sox9, PITX2 and Brn2 are discussed based on recent research results. When Sox9 was overexpressed, cell growth was enhanced while the expression of differentiation-related genes such as loricrin and involucrin was markedly decreased. In contrast, PITX2c overexpression led to increase of differentiation markers at both mRNA and protein levels. Similarly, Brn2 overexpression resulted in increased expression of the differentiation-related genes. These results indicate that keratinocyte differentiation is a dynamic process in which a variety of transcription factors are coordinately involved to balance the proliferation and differentiation.

Modeling volatile organic compounds sorption on dry building materials using double-exponential model

Chang Nyung Kim,Baoqing Deng,Di Ge,Jiajia Li,Yuan Guo 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.7

A double-exponential surface sink model for VOCs sorption on building materials is presented. Here, the diffusion of VOCs in the material is neglected and the material is viewed as a surface sink. The VOCs concentration in the air adjacent to the material surface is introduced and assumed to always maintain equilibrium with the materialphase concentration. It is assumed that the sorption can be described by mass transfer between the room air and the air adjacent to the material surface. The mass transfer coefficient is evaluated from the empirical correlation, and the equilibrium constant can be obtained by linear fitting to the experimental data. The present model is validated through experiments in small and large test chambers. The predicted results accord well with the experimental data in both the adsorption stage and desorption stage. The model avoids the ambiguity of model constants found in other surface sink models and is easy to scale up.