탄성지반과 판의 접촉압력해석에 관한 연구

조현영,정진환,김성도,한층목,Cho, Hyun Yung,Cheung, Jin Hwan,Kim, Seong Do,Han, Choong Mok 대한토목학회 1992 대한토목학회논문집 Vol.12 No.1

A method analizing contact pressure between plate and elastic half space is presented by using F.E.M. With the method, the pressure intensities at surface nodes of half space cae be directly calculated by using flexibility matrix of half space. The method is originally presented by Y.K. Cheung et al.(3) Insted of Y.K. Cheung's method, which use a conception of equi-contact pressure area around each surface nodes of half space in the noded rectanqular element area. We use the equi-contact pressure area around the Gaussian integration points of half space surface in the noded isoparametric element area. Numarical examples are presented and compared with other's studies. 지반을 반무한 탄성체로 가정할 때 판과 지반간의 접촉압력을 유한요소법으로 해석하는 방법은 크게 두 가지로 생각할 수 있다. 그중 가장 직접적인 방법은 판과 지반을 모두 요소로 분할하는 방법이다. 즉 판은 평판요소로 지반은 유한한 범위에서 입체요소로 분할하는 방법을 말한다. 이 방법은 지반의 강성도행렬이 과대해지고 만약 상부구조가 판이 아닌 큰 규모의 구조물일 경우에는 전체강성도행렬이 너무 커지고 강성도행렬의 대폭도 대단히 커지게 되어 실용적 방법이라 할 수 없다. 또 한 가지 방법은 반무한 탄성체의 표면에 집중하중이 작용하는 경우에 대한 Boussinesq의 해를 이용하여 지반전체를 한개의 요소로 취급하는 방법이다. 이 방법을 택할 경우에는 판과 지반의 총접촉절점수와 같은 차수인 유연도행렬의 역을 구해야 한다. 더구나 유연도행렬은 대폭이 행렬의 차수와 동일하고 비대칭이므로 그 역을 구하는 것이 결코 실용적이라 할수 없다. 본 연구에서는 역행렬을 구하는 과정을 회피하는 한가지 방법으로 접촉절점에서의 접촉압력을 먼저 구하여 반력분포를 결정한 다음 상부구조와 지반의 변위 및 응력을 개별적으로 구하는 방법을 사용한다. 이 방법은 Cheung 등이 최초로 사절점 직사각형요소에 대하여 이론상으로만 제안한 것이나, 판의 절점위치에서의 등가접지압이 일정한 지배영역에 등분포한다고 가정하고 있다. 본 연구에서는 8절점 등매개변수요소를 이용하여 곡선경계의 요소분할이 가능하도록 하였고 판의 한 요소와 접하는 지반영역을 Gauss 적분의 가중값과 통일한 넓이의 소영역들로 분할하여 각 소영역에 Gauss 적분점에서의 접지압이 등분포한다고 보고 계산한 점이 다르다.

저수지의 육수학적 연구 ( 제1보 )

조현영,홍사욱 ( Hyun Young Cho,Sa Uk Hong ) 한국하천호수학회 1970 생태와 환경 Vol.3 No.1·2

The chemical environmental factors of several artifical reservoir in the Kang won and Chung chong buck do are investigated during spring season, 1969. The thermal stratification is formed when the wide surface of the shallow ground water has come into contact with the atomosphere, the temperature of which is higher than that of ground water in the day time. The amounts of COD, Cl^-, SiO₂, Total hardness and Alkalinity in the bottom layer water inclined to increase than in the upper layer water. Regarding the amounts of chemical constituents in those artifical reservoirs its belong to oligotropic lake with characterless.

감조하천의 (感潮河川) 위생화학적 연구 - 해수가 김포부근 한강수에 미치는 영향 -

조현영,임중기,홍사욱 ( Hyun Young Cho,Choong Ki Lim,Sa Uk Hong ) 한국하천호수학회 1971 생태와 환경 Vol.4 No.3·4

At the high tide in the main stream of the Han river near the Gim po increase of chloride and hardness was ohserved but as reason for from the estuary it seemed to be no difference water quality between upper and lower layer, At lower tide the water quality in this area are belong to the fresh water and the water qualities of this area are as similarly as that of the Han river near Seoul city.

금강하구의 (錦江河口) 이화학적 (理化學的) 수질환경과 저서생물에 (底棲生物) 관한 연구

조현영,나규환,홍사욱 ( Hyun Young Cho,Kyu Hwan Ra,Sa Uk Hong ) 한국하천호수학회 1978 생태와 환경 Vol.11 No.1·2

1. Seasonal variation of water and the influence of tidal current have investigated in the lower Keum river from Kang kyeong to Ung po, the period from July 1977 to April 1978. 2. The value of DO in this area didn`t found any difference in each site but according to the seasonal variation of DO in this area in the Spring it found 10.5∼11. lppm as almost higher value. The values of NH₃-N, NO₃-N and NO₂-N were not 0.05∼.0.09ppm, 0.1∼0.24ppm and 0.02∼0.13ppm respectively and didn`t found any difference in each site and each season. In generally the value of PO₄^(-3) and COD was 0.03∼0.07ppm and 0.02∼0.13ppm and also didn`t found any difference in each site and season. Judging from the value of PO₄^(-3) and COD it was not yet so pollution. 3. Due to the difference between the rise and fall of tide, the influence of a tidal current show a much disparity. But this investigation was proceed markly the time of low tide and the begining of low tide when the tidal current in the Kang kyeong area of Keum river was severely influenced, The value of Cl^- show 3224.4ppm and the value of K, Na and total hardness show also higher values, such as 71.3ppm, 1085.7ppm and 1228.0ppm respectively. In the Ung po area of this Keum river, the value of those were more higher than in Kang kyeong area. The each value of Cl^- and Na were 9084.8ppm and 4957.7ppm respectively, so it was received severely in the influence of tidal current in this area. Judging from the value of SAR, the value was 43.8 and not suitable for agricultural use. In the time when value of Cl^- was most low the value of Cl^- were 27.3ppm and 44.3ppm in the Kang kyeong and Yong du respectively, and also 61.6ppm and 374.3ppm in each of Kat gae and Ung poareas respectively. In this time the value of Na were 36ppm and 42.5ppm in the water of Kang kyeong and Yong du areas and 43.2ppm and 234.3ppm in the water of Kat gae and Ung po areas respectively. According to the SAR value the value was 7.9 in the water until Kat kae area it is suitable for agricultural use. 4. In view of aquatic creature the plankton that found in the north ocean or brackish areas such as Cosinodiscus anguste-lineatus, Melosira octogona, and Mestagloia sp, are dominant in this area but almost did not found any benthos.

조정방정식법(調整方程式法)(혹은 이완방정식법(弛緩方程式法))과 연속량(連續梁)에의 응용(應用)

조현영,김미옥,Cho, Hyun Yung,Kim, Mi Ock 대한토목학회 1994 대한토목학회논문집 Vol.14 No.3

강절(剛節) 뼈대 구조물(構造物)의 해석(解析)에 적용하는 모멘트 분배법은 총조정(總調整) 모멘트라는 개념을 이용하여 연립방정식(聯立方程式)으로 간단히 표현된다. 이 방정식(方程式)은 간단한 손계산기(hand calculator)로 직접 작성되고 쉽게 풀어질 수 있다. 이 방정식(조정방정식(調整方程式))은 무한번의 분배 과정을 완료한 상태를 나타내며 그 해는 소거법(消去法)으로 풀 수도 있으나 일종의 이완방정식(弛緩方程式)으로써 되풀이 산법을 사용하면 간단히 풀어진다. 이 방법이 연속량(連續梁)의 휨 모멘트 계산이나 영향선(影響線) 해석(解析)에 어떻게 이용될 수 있는 지를 두개의 예제로서 설명하였다. 특히 영향선의 해법은 전산에 편리하도록 행렬(行列)로 표현하였다. Moment distribution procedure in the elastic analysis of rigid frames can be easily expressed with the adjusting moment equations(or relaxation equations) by using the concept of total adjusting moment at each joint after infinite cycles of moment distribution. Adjusting moment equations are a set of simultaneous equations from which the total adjusting moments at each joints after infinite cycles of physical relaxation can be determined. The form of simultaneous equations is a kind of relaxation equations and can be easily solved by the hand calculators. A unique and simplified procedure for the influence line analysis of a continuous beam is presented as an application of the method.

흡연자의 정서조절이 담뱃갑 경고그림 효과에 미치는 영향

조현영 ( Cho Hyun Young ),박준우 ( Park Joon Woo ),전승우 ( Chun Seungwoo ) 한국소비자학회 2018 소비자학연구 Vol.29 No.3

본 연구는 정서조절이 담뱃갑 경고그림 효과에 어떤 영향을 미치는 지 알아보고자 했다. 많은 선행연구가 경고그림이 금연의도에 기여함을 보였지만 일부 연구는 경고그림의 효과를 부정하거나 오히려 그것이 흡연 행동을 증가시킴을 보여주었다. 본 연구는 흡연자의 정서조절 성향을 경고그림의 효과를 조절하는 경계 조건으로 설정하였다. 정서조절은 재평가와 정서억제 전략으로 나눌 수 있다. 재평가는 부정적 정서를 일으킨 상황을 긍정적인 방향으로 해석하여 정서를 조절하는 전략이며 정서억제는 느끼는 감정을 겉으로 표현하지 않는 전략이다. 선행 연구는 재평가가 정서억제보다 적응적인 전략임을 보고한다. 본 연구는 재평가 성향이 높은 흡연자는 경고그림이 유발한 부정적 정서를 적절히 조절해 높아진 금연의도를 보일 것으로 예상했다. 반면 정서억제 성향이 높은 흡연자에게서는 부정적 정서의 매개효과가 나타나지 않을 것이라고 예상했다. 가설을 검증하기 위해 흡연자 205명을 대상으로 실험을 실시하였다. 참가자는 경고그림 또는 경고메시지에 노출된 후 부정적 정서를 느낀 정도, 금연의도 및 정서조절 성향을 측정하는 문항에 응답했다. 실험 결과, 참가자들은 경고문구보다 경고그림에 노출되었을 때 더 높은 부정적 정서와 금연의도를 보였다. 정서조절 성향을 재평가와 정서억제로 나누어 분석해 보니, 재평가의 조절효과는 통계적으로 유의하였지만 정서억제의 조절효과는 유의하지 않은 것으로 나타났다. 즉, 재평가 성향이 높은 흡연자들에게서만 담뱃갑 경고그림이 금연의도를 높이는 효과가 관찰되었으며, 정서억제 성향은 경고그림의 효과에 영향을 미치지 않았다. 또한, 담뱃갑 경고와 금연의도 간의 관계를 흡연자가 인식한 부정적 정서가 매개하는 효과도 재평가 성향에 의해 조절되었다. 반면 정서억제의 조절된 매개효과는 통계적으로 유의하지 않았다. 이 결과는 경고그림에 수반되는 부정적 정서의 순기능이 재평가 전략을 사용하는 흡연자에게서 더 증폭될 수 있음을 보여준다. 따라서 흡연자들이 재평가 전략을 사용하도록 돕는 금연 프로그램을 적극적으로 도입해볼 만하다. The current study examined how emotion regulation strategies moderate the impacts of graphic health warning (GHWs) on intention to quit smoking. Existing literature have shown that cigarette pictorial warnings are effective in reducing smoking behavior. Some studies, however, have revealed insignificant impact of GHWs or boomerang effect such that pictorial warnings even increased smoking behavior. The present study attempted to identify a boundary condition that moderates the impact of pictorial warnings on smokers’ desire to quit smoking. We hypothesized that the impact of GHWs will depend on the type of emotion regulation strategies that the smokers often use to regulate their negative emotions. Two different types of emotion regulation strategies are widely known. First, reappraisal occurs before emotional arousal is fully experienced and encourage people to think of the situation that induce such emotional reaction in a more positive way. For example, a person who feels very nervous waiting for a job interview may reduce such nervousness by thinking the situation as an opportunity to receive a useful feedback on his or her aptitude and skills. Individuals with greater reappraisal tendency attempt to reduce a detrimental impact of negative emotion through interpreting a specific situation that induce the emotion in a more positive manner. In contrast, suppression strategy does not contain such a cognitive process. Individuals with greater suppression tendency try not to reveal one’s emotional feelings in order to regulate their emotions. Literature on emotion regulation consistently have shown that reappraisal is more adaptive than suppression strategy in reducing negative emotional feelings. Suppression strategy was shown to reduce emotional expressions but not to reduce emotional experiences. Also, individuals with greater suppression tendency showed increased activities in sympathetic nervous system as well as heart rate. Suppression, compared to reappraisal strategy thus appear not to solve underlying emotional experiences. Based on the literature we predicted moderated mediation effect of the type of emotion regulation strategy such that mediating role of negative emotion will be significant for smokers with high reappraisal tendency but not for those with high suppression tendency. Smokers with high reappraisal tendency were predicted to regulate their negative emotion induced from GHWs more effectively since they will regard the pictorial warnings as useful information, which results in enhanced desire to quit. Smokers with high suppression tendency were predicted to be relatively ineffective in reducing their negative emotion and their desire to quit thus would not be affected by GHWs. We conducted experiments with 205 Korean smokers and presented them with either a pictorial warning or a text-only warning. Pictorial warning depicts a cancerous lung in full color along with corresponding texts. A text warning was included at the front and side of the cigarette package. The front warning was “Smoking causes various diseases such as lung cancer! Would you still smoke?” and the side warning was “The tar intake may vary depending on the smoker's smoking habits.” After participants were presented with stimuli they indicated the extent to which they felt negative emotions including fear and answered to an emotional regulation scale. The data revealed that participants showed greater level of negative emotion as well as increased desire to quit after exposed to a pictorial warning than to a text-only warning message. The pictorial warning was effective in enhancing desire to quit smoking only for the smokers whose reappraisal tendency was high. Suppression tendency did not significantly moderate the relationship between cigarette pictorial warning (vs. text-only warning) and desire to quit. Also, negative emotion mediated the relationship between cigarette pictorial warning (vs. text-only warning) and desire to quit, and this mediation effect was moderated by reappraisal but not by suppression tendency. The current findings seem to suggest that detrimental impacts of negative emotion that is induced by exposure to cigarette pictorial warnings can be reduced through emotion regulation, especially reappraisal tendency. Also, this study suggested that lack of emotion regulation could have explained previous findings that failed to show effectiveness of cigarette pictorial warnings in reducing smoking behavior. Specifically, reappraisal but not suppression tendency is shown to be more adaptive strategy in smoking cessation. Such finding may in part be due to the fact that suppression strategy requires more amount of cognitive resources than reappraisal strategy. Smoker with high suppression tendency could not have sufficient cognitive resources that is enough to process pictorial warning messages and thus might not have accepted it. Previous studies have demonstrated that the impacts of GHWs are mediated by cognitive processes such as perceived risk of smoking, believability of warning messages, and perceived information effectiveness. Suppression compared to reappraisal strategy appears to interfere with such a role of cognitive factors. The present finding has practical implication. Smoking cessation program for smokers should adopt some form of emotion regulation training. For example, the program can provide a meditation session with smokers that is helpful in reappraise their negative emotion. The current study shows beneficial role of emotion regulation tendency in enhancing GHWs’ effects. Our findings seem to reconcile recent controversy on the effectiveness of cigarette pictorial warning in Korea. This study demonstrated that GHWs are effective communication tool for smokers in helping their smoking cessation attempts. There are some situations, however, in which pictorial warning messages are ineffective due to negative emotional responses towards such messages and GHWs seem to be ineffective communication tool for smokers with low emotion regulation tendency.

Degenerate 쉘 요소에 의한 기하학적 비선형 해석

조현영(Hyun Yung Cho),정진환(Jin Hwan Cheung),김성도(Seong Do Kim) 한국강구조학회 1990 韓國鋼構造學會誌 Vol.2 No.2

The degenerate shell element is considered for the geometrically nonlinear finite element analysis of shells. Total Lagrangian formulation is used for describing the nonlinear responses. To overcome the locking phenomenon of the degenerate shell element(9 node Heterosis element), selectively reduced integration technique(bending stiffness-3×3 rule, shear stiffness-2×2 rule, membrane stiffness-2×2 rule) is introduced. This element exhibits good performance even for thin shells. The Arc-length method, in combination with the modified Newton-Raphson technique, has been applied for finding limit points and tracing the post-critical responses(snap-through and snap-back problems). Numerical examples are solved to assess the performance of the degenerate shell element under geometrically nonlinear conditions including post-critical behaviors.

Cross 分配過程의 級數公式에 依한 한 處理法 〈其 1〉

趙顯榮(Cho Hyun Yung) 대한토목학회 1968 대한토목학회지 Vol.15 No.4

Cross 分配過程의 級數公式에 依한 한 處理法 〈其 2〉

趙顯榮(Cho Hyun Yung) 대한토목학회 1968 대한토목학회지 Vol.16 No.1

行列級數를 利用한 彈性받침連續보의 解法

趙顯榮(Cho Hyun Yung) 대한토목학회 1969 대한토목학회지 Vol.17 No.2