사장교의 초기인장력과 주탑좌표를 고려한 최적설계

김경승,김문겸,황학주,Kim, Kyung Seung,Kim, Moon Kyum,Hwang, Hak Joo 대한토목학회 1988 대한토목학회논문집 Vol.8 No.2

It is not a simple task to optimize a cable stayed bridge, because it involves, in addition to the section properties, number and arrangement of cables, initial tension forces of cables, and type and height of the tower as design variables. This study deals with an optimization problem of cable stayed bridges considering initial cable forces, section properties of the girder and the tower, and coordinates of the tower. In order to avoid difficulties in dealing with numerous variables which interact mutually, separate design spaces are adopted for initial cable forces, section properties, and coordinates, respectively. Strain energy stored in the structure is used as the object function in the design of the initial cable forces, while weight of the structure is used in the design of section and coordinates. Upper and lower limits of the initial forces, allowable stresses including the effect of buckling, and lower limit of the sectional area are considered as constraints. The proposed method is applied to a fan type bridge and a harp type bridge. It is believed through comparison of the results to the previous results in the literature that the proposed method renders rational design values. It is also shown that the coordinate optimization, which is usually deleted in the optimization process, results in additional saving of materials. 사장교는 그 설계에 있어서 케이블의 개수와 배치형식, 케이블의 초기인장력, 주탑의 지지형식과 높이 등 거어더와 주탑 단면외에도 설계변수가 많으므로 효율적인 설계를 하는 것이 쉽지 않다. 본 연구에서 케이블의 초기인장력, 거어더와 주탑의 단면, 주탑의 높이를 설계변수로 하여 사장교의 설계를 최적화하는 문제를 다루었다. 서로 상호작용을 하는 여러 설계변수를 동시에 최적화하는 어려움을 피하기 위하여 본 논문에서는 초기인장력, 단면, 주탑의 좌표를 각각 독립된 설계공간에서 최적화하였다. 목적함수로서는 초기인장력 공간에서는 전체구조의 변형에너지를, 단면 및 좌표의 공간에서는 재료의 총중량을 취하였다. 제약조건으로는 초기인장력의 상하한계, 부재의 좌굴을 고려한 응력, 단면적의 하한계를 고려하였다. 대표적인 Fan형 및 Harp형 사장교를 최적설계한 결과, 제시된 방법에 의하여 합리적인 결과를 얻을 수 있음을 보이고, 기존의 최적화에서 고려하지 않았던 좌표의 최적화를 통하여 경제성을 얻을 수 있다는 것을 밝혔다.

마인드풀니스를 통한 스트레스 대처와 임상적 활용

김경승,Kim, Kyung-Seung 한국정신신체의학회 2008 정신신체의학 Vol.16 No.1

1980년대 이후 마인드풀니스를 활용한 다양한 치료 프로그램들이 임상 현장에서 적용되고 있으며 최근에는 교육 현장에서도 활용되고 있다. 본고에서는 최근에 발표된 마인드풀니스 관련 단행본과 학술잡지를 연구하여 마인드풀니스의 의미와 MBSR, MBCT, ACT, DBT 등의 임상적 활용에 대해 고찰한 결과 마인드풀니스는 스트레스 극복을 통한 다양한 정신신체질환에 적용 가능할 뿐만 아니라 불안증, 우울증, 식이장애 등 정신과적 질환에 적용가능하며 새로운 정신사회적 치료의 한 가지로 활용될 수 있는 가능성을 보여주고 있다. Several treatment programs putting mindfulness to practical use are being utilized in the various clinical settings as well as educational fields since 1980's. In this article, I studied several books and journals related with mindfulness and tried to show that mindfulness may have its neural circuits in the brain and can be utilized in the form of MBSR, MBCT, ACT, DBT not only to reduce stress and the symptoms of various psychosomatic conditions but to be applied to psychiatric illness such as, anxiety disorders, depressive disorders, and eating disorders, predicting its usefulness as a new psycho-social treatment.

울산 지역 정신건강증진기관 및 의료기관 이용 정신질환자의 자살생각 관련요인

이경숙(Kyoung Sook Lee),고유미(Yu Mi Koh),김경승(Kyung Seung Kim) 대한신경정신의학회 2021 신경정신의학 Vol.60 No.4

Objectives This study was undertaken to explore correlations between depression, alcohol drinking, psychiatric symptoms, and suicidal ideation, and to identify factors related to suicidal ideation in the mentally ill. Methods A survey was conducted using a self-reported questionnaire. Data were collected from July to September 2020. The study participants were 212 individuals with various major mental disorders. Results Depression was found to be positively correlated with alcohol drinking, psychiatric symptoms, and suicidal ideation. Alcohol use was positively correlated with psychiatric symptoms and suicidal ideation, and psychiatric symptoms were positively correlated with suicidal ideation. Factors influencing suicidal ideation included suicidal attempts, psychiatric symptoms, depression, and awareness of the mental health crisis hotline. Multiple regression analysis showed these variables explained 61% of suicidal ideation. Conclusion The study shows that to prevent suicide among the mentally ill, focus should be placed on reducing depression, alcohol drinking, and psychiatric symptoms and improving awareness of the mental health crisis hotline.

알코올 의존 환자에서의 12단계 척도의 신뢰도와 타당도 연구

정성수(Sung Soo Jung),하태민(Tae Min Ha),김경승(Kyung Seung Kim),이성근(Seong Keun Lee),심주철(Joo Cheol Shim),공보금(Bo Geum Kong),정도운(Do Un Jung) 대한생물치료정신의학회 2014 생물치료정신의학 Vol.20 No.1

Objectives:This study is aimed to assess the reliability and validity of the Twelve Step Scale which are newly developed to observe the direct effect of the twelve step facilitation therapy that has been widely used for the treatment of patients with alcohol dependence. Methods:110 patients who were diagnosed with alcohol dependence by psychiatrists using DSM-TR criteria agreed to participate in the study. Subjects were assessed by questionnaires including demographic data and alcohol related clinical rating scales such as Twelve Step Scale, Korean version of Alcohol Use Disorders Identification Test, Alcohol Dependence Scale, Hanil Alcohol Insight Scale when informed consents were acquired. Four weeks later after initial assessment, Twelve Step Scale was reassessed for subjects who were treated over 3 months at the same hospital without recent admission or discharge for a month. Results:The average of the Twelve Step Scale was higher in female patients than in male. In addition, there is positive correlation between HAIS and Twelve Step Scale. According to factor analysis, Twelve Step Scale has two factors. The results showed significant internal consistency reliability(Cronbach’s α=0.92) but did not show reasonable test-retest reliability. Conclusion:This study showed that the Twelve Step Scale had reasonable reliability and validity except test-retest reliability. Thus the Twelve Step Scale can be used to assess the direct effects of twelve step facilitation therapy, which in turn might contribute to enhance twelve step facilitation therapy in the future.

사장교의 단면최적화에 관한 연구

김경승 광주대학교 1993 産業技術硏究 Vol.3 No.-

수려한 외형과 경제적인 구조로 평가되는 사장교는 장경간 교량에 광범위하게 이용되어 왔다. 그럼에도 불구하고 그 건설이 시작된 것은 최근으로, 그 이유는 케이블 배치형상, 주탑의 지지조건 등 많은 설계변수들에 의한 대안이 존재하고, 그에 따른 해석과 설계가 쉽지 않기 때문이다. 이들 설계변수 중에서 지간은 교량가설장소, 기초부의 상태에 따라 결정되고, 주탑의 높이는 지간-주탑높이 비, 케이블 배치형상, 미적인 배려에 의해서 고려되는 것이 일반적이므로 최적화의 대상이 아닌 경우가 일반적이다. 따라서 본 논문에서는 사장교 단면최적화의 문제와 그에 따른 단면변수를 효율적으로 다루는 방법을 다루고자 한다. Cable-stayed bridges which combine ecomony and beauty, have been extensively employed in constructing long-spanned bridges. Selecting proper structural types has been, however, problematic since the bridges have many design alternatives, including: the configuration of cables, the number of cables, and support condition of towers, etc. In these design variables span length is generally determined from bridge site conditions and tower height determined from sveral considerations, such as the relation of tower height to span length, the type of cable arrangement, and the aesthetic proportions. Therefore this paper introduces an optimization of member forces and cross-sections with sectional properties.

변위제약조건을 고려한 사장교 케이블의 초기인장력 최적화

김경승 광주대학교 산업기술연구소 2002 産業技術硏究 Vol.16 No.-

사장교는 케이블에 인장력을 도입함으로서 경제적인 설계가 가능한 구조이다. 사장교의 설계에 있어서 최적 초기인장력을 결정하는 문제는 가장 중요하고도 어려운 문제이다. 고정하중 상태에서 주어진 들보의 수직형상에 따른 초기 인장력을 결정하는 것은 사장교의 전반적인 설계에 영향을 미치므로 중요한 문제이다. 논문에 사용된 기법의 이론적 특성은 전체 중앙견간의 수직변위를 초기형상에 맞추어서 케이블 인장력의 제곱합이 최소화되도록 하는 것이다. 이것은 재래적인 수직변위 영의 기법에 비해 합리적이고 단순하며, 강지점으로 지지된 연속보에서 얻어지는 휨모멘트에 도달하는 들보와 유사성을 갖게된다. 본 논문에서 제시한 해석적 기법의 적용성은 돌산대교를 수치해석 예제로 하여 입증하였다. Cable-stayed bridges can be designed economically by cable prestressing. It is a most important and difficult problem to determine the optimum initial cable forces in the design of cable-stayed bridges. The determination of initial cable forces in cable-stayed bridges for a given vertical profile of deck under its dead load is an important but difficult task that affects the overall design of the bridge. One of the theoretical characteristics of the technique is to minimize the sum of squares of prestressing forces to evaluate the initial shape considering fabrication camber. It is much more rational and simple than the traditional "zero displacement" method, and it is able to achieve bending moments in the bridge deck approaching those in a continuous beam over rigid simple supports. The usefulness and applicability of the analytic method proposed in this study are demonstrated by numerical example as Dolsan bridge.

횡단교 설계시 미적인 고려사항

김경승 광주대학교 1997 産業技術硏究 Vol.8 No.-

교량의 미관적 요소는 흔히 장대교에서 검토되는 사항이다. 그러나 장대교에 비하여 일반도의 횡단교나 인터체인지 등의 소교량의 수가 훨씬 많다. 따라서, 장대교 못지 않게 이러한 교량의 조형미는 중요하다 할 수 있다. 교량이 산간지나 하천에 존재할 경우에는 주위경관에 흡수되어 눈에 들어오지 않는다. 이에 반하여 도로의 횡단교는 주행중 운전자들의 시야의 전방에 들어오게 되며, 지루한 자동차여행에 변화요소가 된다. Treaties on bridge aesthetics often address the long-span bridge of a spectacular setting, These bridge sites are relatively few in number, and most designers are usually involved with more mundane highway interchange structures of relatively short span. In some respects, however, these more routine bridges require as much, if not more, consideration of aesthetics as the former. The bridge in a spectacular setting may not be noticed, because the scenery dominates. On the other hand, overpass structures in flat country cannot escape notices, and they may be one of the few variations for motorists on long and sometimes tedious journeys.

강상판 사장교의 포장방법에 관한 비교 연구

金庚承 광주대학교 1989 論文集 Vol.6 No.-

The application of principles of engineering economy to pavement projects occurs generally at two levels. First, there are the management decisions required to determine the feasibility and programming of project ; second, there is the requirement to achieve the maximum econmy within the project. The second level might be considered suboptimization with respect to the first level, but it is more important to the designer. In order to decide the material for Delsan bridge deck pavement, it was carried out to inspect closely signs of cracking for the Kimhae bridge pavement and analyze the cause of failure for the Jindo bridge surfacing. As the result of this, it is concluded that Latex Asphalt is the most adequate for the material of steel plate deck pavement, considering domestic condition, namely, a climatic influence, construction equipments, construction period and costs, etc.

변형에너지 최소화에 의한 사장교 케이블인장력 최적화

김경승 광주대학교 산업기술연구소 1992 論文集 Vol.1 No.-

사장교는 케이블에 초기인장력을 도입함으로써 경제적인 설계가 가능한 구조이다. 따라서, 사장교의 설계과정에서 최적의 케이블인장력을 결정하는 것은 가장 중요성하고도 어려운 문제이다. 그러나, 최적인장력에 관한 연구는 많치 않았다. 본 논문에서는 변형에너지 최소화에 근거를 두고 사장교의 최적인장력 결정방법을 연구하였다. 최적인장력을 구하기 위한 방법으로써의 변형에너지 기준의 타당성은 간단한 사장교모델에 의해 증명하였다. 본 논문에서 제시한 변형에너지 기준은 등간격으로 배치된 다중케이블 형식에서 최적인장결을 결정하는 데 매우 유용하다. Cable-stayed bridges can be designed economically by introducing the cable prestresses. It is the most important and difficult problem to determine the optimum cable prestresses in the design of cable-stayed bridges. However, there are few studies on the optimum cable prestresses. In this study, an attempt is made to determine the optimum cable prestresses based on the strain energy criterion. The validity of the strain energy criterion on the optimum cable prestresses is proved by simple models. The results show that the proposed strain energy criterion is very useful to determine the optimum cable prestresses even in the case of multi-cable types.

매트릭스 구조해석을 위한 화면출력의 이용에 관한 연구

金庚承 광주대학교 1990 論文集 Vol.7 No.-

In the case of structural analysis by computer, precise data-input is indispensible for exact solutions. Producing graphics by computer for many types of applications, especially those involving massive amounts of data or repetition, is more efficient than by traditional manual methods. Graphic display of bending moments, shearing forces and deformations show ralative magnitude with each elements. Comparison of section forces and allowable values by graphic display can be used for structural design. As a futher study, the automation of above-mentioned contents can make optimal structural design possible.