혈청 요산 농도에 따른 대사증후군의 위험도

김성걸,박현아,황동희,김철환,강재헌,황의경,남옥연,백승호,이성희 대한가정의학회 2007 Korean Journal of Family Medicine Vol.28 No.6

Risk of the Metabolic Syndrome according to the Level of the Uric AcidSeong Keol Kim, Hyun Ah Park, Ok Yeon Nam, Seung Ho Beck, Dong Hee Whang*, Ue Kyong Hwang, Cheol Hwan Kim, Sung Hee Lee, Jae Heon Kang† 연구배경: 여러 역학적 연구에서 고요산혈증은 심혈관계 질환 및 인슐린 저항성, 대사증후군과의 유의한 관련성이 보고되어 있으나, 국내에서는 건강한 성인을 대상으로 혈청 요산 농도와 대사증후군의 관련성을 평가한 연구는 많지 않다. 저자들은 국내의 건강한 성인 남성을 혈청 요산 농도에 따른 대사증후군의 분율과 구성 요소들과의 관련성, 위험도를 확인해 보고자 본 연구를 시행하였다. 방법: 2005년 2월부터 4월까지 일개 대학병원 건강증진센터에서 건강검진을 받은 20세부터 65세까지의 건강한 남성 206명을 연구 대상으로 혈청 요산 농도를 사분위수의 네 군으로 분류한 후 인슐린 저항성 및 대사증후군 구성 요소들과의 관련성을 평가하고 대사증후군의 교차비(odds ratio)를 구하였다. 결과: 혈청 요산 농도가 제1구간에서 제4구간으로 높아짐에 따라 체질량지수(P<0.001), 수축기 혈압(P=0.015), 이완기 혈압(P=0.015), 공복 인슐린(P=0.038), 중성지방(P=0.005)은 의미 있게 증가하였고, 고밀도 콜레스테롤(P=0.008)은 감소하였다. 요산 농도가 높아질수록 대사증후군의 유소견자의 비율은 각각의 구간에서 13.7%, 15.7%. 18.9%. 36.0%로 유의하게 증가한 반면(P=0.007), HOMA-IR로 측정한 인슐린저항성에는 유의한 증가가 없었다. 요산 농도 제1구간을 기준으로 하였을 때 제2, 제3, 제4구간의 대사증후군에 대한 보정 교차비는 각각 1.42 (0.39~5.14), 1.14 (0.33~3.92), 4.00 (1.15~13.89)였다. 결론: 혈청 요산 농도의 증가는 대사증후군의 구성 요소들과는 유의한 관련성이 있으며, 대사증후군의 위험도 증가와 유의하게 관련되어 있었다. 향후 전향적 관찰을 통해 혈청 요산 농도가 대사증후군 발생의 위험 요인이 되는지 연구가 필요하다.

A study on the design of a new power transmission for wind turbines

김성걸 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.3

The single-rotor wind turbine remains the dominant design for energy production. However, this design requires improvements toovercome some of its limitations. The introduction of the dual rotor system regarded as improvement over the single-rotor system inKorea due to its high efficiency, despite Korea’s low wind quality. Many researchers have attempted to devise different dual rotor machinesand assess their power production capabilities under similar wind conditions to those in Korea. Existing power transmissions fordual-rotor wind turbines have issues with the complexity of design, difficulty in manufacturing, high costs and low efficiencies. Therefore,the aim of this study was to design a new power transmission for the dual-rotor wind turbine with an alternative to the bevelplanetarysystem by using a planetary system. This new method is dependent on the torque ratio and not the gear ratio as in common gearsystems. The design and analysis of each part, such as the gears, shafts, bearings and control mechanisms are included in this study. Thedesign is based on the power transmission of a motor vehicle. A prototype of the design is manufactured to verify the proposed method. The experimental results show that the new planetary-type gear box incurs fewer energy losses, has a high efficiency and low manufacturingcosts. It is anticipated that the proposed design might be suitable for use with commercial wind turbines.

미국의 동아시아 공해전투(ASB) 고찰

김성걸 한국군사학회 2013 군사논단 Vol.73 No.-

It is worrying that the United States is likely to project military force from its mainland to an operational area with being now opposed unlike for the past decades. The research and development effort for military technology and rapid proliferation of hi-tech weapons is enabling states and non-state groups to implement anti-access and area denial(A2AD) strategy evcrywhere in the world. China is especially pursuing such strategy. It has focused on building up its military force and now challenging the hegemony in the west Pacific domain including the East China Sea and South China Sea, a sphere long dominated by the U.S.. In response to these security circumstances, the Unircd States has proposed a series of principles to achieve operational access despite armed opposition. Air-Sea Battle concept, together with concepts on entry operations or littoral operations follows Joint Operational Access Concept (JOAC) which is part of a broader national approach. So, ASB is a limited operational concept that focuses on the development of integrated air and naval forces in the context of A2AD threats. The central idea of JOAC is cross-domain synergy, and the key idea of ASB is networked, integrated attack-in-depth. One of the common characteristic of these ideas is the integration across domains. The meaning of integration is more emphasized than the word of jointness. The integrated forces arc institutionalized at lower echelons than ever before. These forces create the tempo and exploit asymmetrical advantages inherent in a joint force. Another common characteristic of these ideas is to instantaneously strike the targets from beyond the horizon. For instance, long-range weapons can easily penetrate the A2AD. The Pentagon has increased investment in the systems and capabilities related to ASB in both FY 2012 and FY 2013 budgets. Consequently, the U.S. decided to maintain its aircraft carrier fleets at current level -11 ships and 10 air wings- and continue with the purchase of 2,400 F-35 Lightening Ⅱ, notwithstanding defense budget cut. Moreover, the Pentagon is investing a growing amount resources in DDG-51 Aegis destroyer, Littoral Combat Ship, P-8A Poseidon maritime patrol aircraft, C-5 Galaxy transporter, Evolved Seasparrow missile, Standard family of missiles, Air-to-air missile, KC-46A Tanker, Army's communication network (WIN-T) and Patriot/PAC-3 missile. ASB internally places a renewed emphasis on integrating inter-service, institutionalizing integrated arrangements and engendering the “culture of change” for active collaboration between the services. Externally, this builds and sustains fruitful international partnerships with the American allies, partners and friends. So, considering the importance of this widespread concept, our country, as an ally of the U.S., should also pay attention to the development of ASB.

Improvements for reduction of the brake squeal noise at Seoul metro rolling stock on tracks

김성걸 대한기계학회 2009 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.23 No.8

Experimental and theoretical methods were applied to find and understand the phenomenon of brake squeal noise of the Seoul Metro rolling stock on tracks. Generally, it is well known that brake squeal noise is strongly related to stick and slip between brake pad and disk. In most cases for rolling stock on tracks, trailer cars needed more particular attention through the tests, because they were the major sources of brake noise due to frictional braking. There are two types of rolling stocks in Seoul Metro: chopper and VVVF. Both types of rolling stocks for lines 1 and 3 in the Seoul Metro were used for experimental analyses. To study brake squeal noise under various braking conditions, dynamometer tests were performed at the S&T Brake, Co., which is one of major manufacturers of brake pads for rolling stock on tracks. For measuring brake squeal noise, acoustic tests were performed with a microphone in the Gunja depot. And modal tests for brake parts, which consisted of brake lining, brake lining pad, and back plates, were executed to obtain the natural frequencies related to the brake squeal noise. Also, modal tests of the whole brake assembly and lining block were performed at the heavy maintenance shop of the Gunja depot. The mode analysis using an ANSYS was simulated to determine the relations between the mechanisms of brake squeal noise. As the results of the tests and the simulations, it was found that specific natural frequencies of the brake parts affected squeal noise, and also, the reason to create squeal noise. Finally, improvements for reducing squeal noise were proposed, and applied to lines 2and 3 at Seoul Metro rolling stock on tracks.

학술논문 : 중국의 반접근(A2),지역거부(AD) 군사능력 평가

김성걸 한국군사학회 2012 군사논단 Vol.70 No.-

플립칩 솔더 접합부의 신뢰성 평가를 위한 보드레벨 낙하해석

김성걸,김주영,김상현,양우찬,정호동,김재호 한국공작기계학회 2008 한국공작기계학회 추계학술대회논문집 Vol.2008 No.-

Recently, with the trend towards miniaturization and multi-functionality in electronic products such as mobile phone, miniature IC packages such as Flip Chip package have brought new reliability problems. Reliability of IC packages during the drop impact becomes a critical issue. A Flip Chip package with solder bump composition of Sn-1.2Ag-O.7Cu was modeled, and dynamic response of the drop was analyzed by implicit finite element. analysis (FEA) with ANSYS Multiphysics. Also, model analysis was performed. In the results of the drop impact simulation, the stress and strain state in the solder joints were determined. Various peak acceleration shock G-levels and 0.5msec duration time were applied on the basis of JEDEC standard such as JESD22-B111.

마그네틱 커플링을 사용한 축계의 동적해석 ( Dynamic Analysis of a Shaft System with Magnetic Coupling )

김성걸,이성진,이장무 대한기계학회 1993 대한기계학회 춘추학술대회 Vol.- No.-

자동차 시트 및 마네킹 시스템의 진동 Ⅱ ( Vibration of Car Seat and Mannequin System Ⅱ )

김성걸,김준현,박기홍 대한기계학회 2001 대한기계학회 춘추학술대회 Vol.1 No.2

주파수 변화에 따른 태양전지 전기적 특성 분석

김성걸,홍창우,이경섭,Kim, Seong-Geol,Hong, Chang-Woo,Lee, Kyung-Sup 한국전기전자재료학회 2012 전기전자재료학회논문지 Vol.25 No.5

This study focused on the performance characteristics of solar cell using the impedance technique. We measured an impedance according to frequency from 1 Hz until 1 MHz. It could know that the impedance was decreased according to the frequency increases in solar cell. The impedance of single crystal solar cell was 0.61 ${\Omega}$ at 1 Hz, and kept almost settled value to $1{\times}10^2$ Hz. However, the impedance of polycrystal solar cell was $7{\times}10^3{\Omega}$ at 1 Hz.

북한의 중·단거리 미사일 해부

김성걸 북한연구소 2015 北韓 Vol.- No.517