Numerical Formulation for Multimode Coupled Buffeting Analysis of Cable-Stayed Bridges and its applications

Jaeyoung Cho(조재영),Hakeun Lee 대한토목학회 2007 대한토목학회 학술발표회 논문집 Vol.2007 No.1

In this paper, the multimode frequency-domain approach is applied to the aerodynamic and aeroelastic analysis of cable-stayed bridges that consider construction sequence and temporary stabilizing measures. The accuracy of the analytical and experimental methods used for predicting prototype bridge performance is fundamentally important in assessing bridge safety. Numerical models for accurate buffeting analysis of cable-stayed bridges, especially free cantilever superstructures, are deduced for the vibrations due to extraneously induced excitation caused by turbulence. The expected goal is to develop numerical models upon which to base reliable studies of detailed three-dimensional structural models of bridges. The power spectral density and elemental internal forces of a cable-stayed bridge structure are computed using the developed computational code based on the finite element method and random vibration theory. To determine the aero elastic and aerodynamic parameters of a cable-stayed bridge, section model tests were performed in a wind tunnel. Full aeroelastic model tests are investigated to verify a simulation modeling strategy which is efficient and accurate for two types of cable-stayed bridges with various stabilizing measures in turbulent wind. Moreover, the effects of dynamic transverse wind on cable-stayed bridges for various wind cable arrangements at different stages of completion are investigated. This suggests the most effective placement of wind cables. It is concluded that the multi-mode frequency-domain approach can predict the deflections of the bridge girder and the pylon base moments of the bridge with acceptable accuracy.

SME Internationalization and Performance

Jaeyoung Cho(조재영),Jangwoo Lee(이장) 한국경영학회 2018 經營學硏究 Vol.47 No.6

감정노동이 직무스트레스에 미치는 영향: 회복탄력성의 매개효과를 중심으로

조재영(Jaeyoung Cho) 피터드러커 소사이어티 2018 창조와 혁신 Vol.11 No.2

본 연구의 목적은 감정노동이 종업원의 직무스트레스에 미치는 영향과 회복탄력성의 매개효과를 중심으로 고찰하는 것이다. 연구결과, 독립변수인 감정노동과 직무스트레스의 하위요인인 역할과다, 역할갈등에 독립변수인 감정노동과의 가설이 채택되어 유의미한 영향을 미치는 것으로 분석되었다. 이는 진실한 감정이 없는 상태에서 형식적으로만 고객을 대응하는 구성원일수록, 과도한 역할수행과 과중한 책임으로 인해 직무를 수행하면서 동료들과의 갈등이 발생할 수 있음을 알 수 있다. 다만, 역할의 모호성이 기각된 이유는 매뉴얼 등에 의하여 자신의 업무가 명확히 규정되어 있고 매뉴얼에서 벗어나는 업무를 수행할 수 없기 때문이라고 볼 수 있다. 감정노동과 회복탄력성의 관계는 부정의 관계가 나타났다. 회복탄력성은 어려운 상황에서도 견딜 수 있도록 하거나 위기에서 회복해가는 긍정적인 성향이다. 감정노동은 이러한 긍정성을 감소시키는데 중대한 영향을 미칠 수 있기 때문에 감정노동의 심각성을 다시 한 번 확인할 수 있는 결과라고 할 수 있다. 매개효과 분석결과, 감정노동과 역할모호성의 관계에서 회복탄력성은 매개효과가 있는 것으로 나타났다. 역할모호성에 대해서는 앞서 기술한 바와 같이 회사의 대응지침 등이 존재하기 때문에 직접영향을 미치지는 않지만 긍정성을 기반으로 하는 회복탄력성이 투입될 경우 매뉴얼이 있음에도 자신의 영향력을 발휘할 수 도 있음을 시사하고 있다. The purpose of this study is to focus on the effects emotional labor has on the job stress of employees and the media-effect of resilience. Studies have shown that the adoption of independent variables such as emotional labor, which is a substantiation of job stress, and the hypothesis of emotional labor, which is an independent variable of role conflict, has a significant effect. This can cause conflicts with colleagues as they perform their duties due to excessive role performance and heavy responsibility, as members who respond to customers with no real feelings can only respond to excessive performance. The reason why the role s ambiguity is overruled is that its work is clearly defined by the manual, and it can not be performed to perform any deviations from the manual. The relationship between emotional labor and resilience has come to light. Resiliency elasticity is a positive tendency to make it tolerable in difficult circumstances or to recover from a crisis. Emotional labor can have a significant impact on reducing this positive effect, so it is a good indicator of the seriousness of emotional labor. An analysis of the effects shows that the relationship between emotional intelligence and role ambiguity has a media-effect resilience. It is through resilience to influence the role ambiguity of emotional intelligence. Since role ambiguity may appear when there is no set rule or manual, it will not have a direct effect on emotional labor as there are company response guidelines, etc. However, if resilient elasticity based on positivity is introduced, it suggests that the company may exercise its influence even though it has a manual.

전라북도 서부 해안지역 농업용 대형관정 지하수 수질평가

조재영 ( Jaeyoung Cho ),손재권 ( Jaekwon Son ),최진규 ( Jinkyu Choi ),김영주 ( Youngju Kim ),황선아 ( Seonah Hwang ),정혜란 ( Hyeran Jeong ),김영근 ( Youngkeun Kim ),유상윤 ( Sangyun You ),홍성현 ( Sunghyun Hong ) 한국농공학회 2009 한국농공학회 학술대회초록집 Vol.2009 No.-

본 연구는 농작물의 경작·재배의 목적으로서 농업용수로 이용되며 가뭄을 극복하기 위해 설립한 대형관정의 지하수 수질을 평가하고자 전라북도 서부 해안지역 농업용 대형관정 115개소를 대상으로 수행되었다. 수행된 연구결과를 요약하면 다음과 같다. 지하수 중 pH는 6.01-8.34 범위로 평균은 6.90으로 나타났다. 질산성질소는 0.03-5.80 mg/L의 범위로 평균은 1.62 mg/L로 나타났다. 염소 이온은 7.3-1566.9 mg/L의 범위로 평균은 82.4 mg/L로 나타났다. 염소 이온은 일부 기준치를 초과하였으나, 해안지역의 염수쐐기 현상으로 추정된다. 비소는 0,0001-0.0497 mg/L의 범위로 평균은 0.0226 mg/L로 나타났다. 페놀은 0.0001-0.0048 mg/L의 범위로 평균은 0.0025 mg/L로 나타났다. 납은 0.0003-0.0987 mg/L의 범위로 평균은 0.0256mg/L로 나타났다. 6가 크롬은 0.0002-0.05mg/L의 범위로 평균은 0.0102 mg/L로 나타났다. 시안, 유기인, 수은, TCE, PCE, 1.1.1-트리클로로에탄은 모두 불검출 되었다. 상기 요약한 각 항목의 결과는 농업용수 기준 수치 이하의 수준으로 조사되어 농업용수로서 적합하다고 판단된다. This study was conducted to estimate agricultural water quality for underground well at western coastal area in Jeollabuk-do. Samples were analyzed to contain general water quality index such as pH, NO₃-N, chloride ion, and pollutant material such as CN, organic phosphates, phenol, TCE(trichloroethylene), PCE(tetrachloroethylene), 1.1.1-trichloroethane, Cd, As, Hg, Pb, Cr⁺⁶, respectively. These analyzed data were compared with agricultural water quality standard. As a survey results, underground well at western coastal area in Jeollabuk-do are below the agricultural water quality standard level, it is demonstrate that the groundwater is suit as agricultural water.

기계학습을 이용한 수출신용보증 사고예측

조재영(Cho, Jaeyoung),주지환(Joo, Jihwan),한인구(Han, Ingoo) 한국지능정보시스템학회 2021 지능정보연구 Vol.27 No.1

The government recently announced various policies for developing big-data and artificial intelligence fields to provide a great opportunity to the public with respect to disclosure of high-quality data within public institutions. KSURE(Korea Trade Insurance Corporation) is a major public institution for financial policy in Korea, and thus the company is strongly committed to backing export companies with various systems. Nevertheless, there are still fewer cases of realized business model based on big-data analyses. In this situation, this paper aims to develop a new business model which can be applied to an ex-ante prediction for the likelihood of the insurance accident of credit guarantee. We utilize internal data from KSURE which supports export companies in Korea and apply machine learning models. Then, we conduct performance comparison among the predictive models including Logistic Regression, Random Forest, XGBoost, LightGBM, and DNN(Deep Neural Network). For decades, many researchers have tried to find better models which can help to predict bankruptcy since the ex-ante prediction is crucial for corporate managers, investors, creditors, and other stakeholders. The development of the prediction for financial distress or bankruptcy was originated from Smith(1930), Fitzpatrick(1932), or Merwin(1942). One of the most famous models is the Altmans Z-score model(Altman, 1968) which was based on the multiple discriminant analysis. This model is widely used in both research and practice by this time. The author suggests the score model that utilizes five key financial ratios to predict the probability of bankruptcy in the next two years. Ohlson(1980) introduces logit model to complement some limitations of previous models. Furthermore, Elmer and Borowski(1988) develop and examine a rule-based, automated system which conducts the financial analysis of savings and loans. Since the 1980s, researchers in Korea have started to examine analyses on the prediction of financial distress or bankruptcy. Kim(1987) analyzes financial ratios and develops the prediction model. Also, Han et al.(1995, 1996, 1997, 2003, 2005, 2006) construct the prediction model using various techniques including artificial neural network. Yang(1996) introduces multiple discriminant analysis and logit model. Besides, Kim and Kim(2001) utilize artificial neural network techniques for ex-ante prediction of insolvent enterprises. After that, many scholars have been trying to predict financial distress or bankruptcy more precisely based on diverse models such as Random Forest or SVM. One major distinction of our research from the previous research is that we focus on examining the predicted probability of default for each sample case, not only on investigating the classification accuracy of each model for the entire sample. Most predictive models in this paper show that the level of the accuracy of classification is about 70% based on the entire sample. To be specific, LightGBM model shows the highest accuracy of 71.1% and Logit model indicates the lowest accuracy of 69%. However, we confirm that there are open to multiple interpretations. In the context of the business, we have to put more emphasis on efforts to minimize type 2 error which causes more harmful operating losses for the guaranty company. Thus, we also compare the classification accuracy by splitting predicted probability of the default into ten equal intervals. When we examine the classification accuracy for each interval, Logit model has the highest accuracy of 100% for 0~10% of the predicted probability of the default, however, Logit model has a relatively lower accuracy of 61.5% for 90~100% of the predicted probability of the default. On the other hand, Random Forest, XGBoost, LightGBM, and DNN indicate more desirable results since they indicate a higher level of accuracy for both 0~10% and 90~100% of the predicted probability of the default but have a lower level of accur

전라북도 동부 산악지역 농업용 대형관정 지하수 수질평가

조재영 ( Jaeyoung Cho ),손재권 ( Jaekwon Son ),최진규 ( Jinkyu Choi ),김영주 ( Youngju Kim ),황선아 ( Seonah Hwang ),정혜란 ( Hyeran Jeong ),김영근 ( Youngkeun Kim ),유상윤 ( Sangyun You ),홍성현 ( Sunghyun Hong ) 한국농공학회 2009 한국농공학회 학술대회초록집 Vol.2009 No.-

본 연구는 전라북도 동부 산악지역 농업용 대형관정의 지하수를 중심으로 101개 농업용수 지하수의 경작·재배이용이 가능한지 알아보고자 수행하였다. 수행된 연구결과를 요약하면 다음과 같다. 조사한 지하수 중 pH는 6.01-8.48의 범위로 평균값은 7.21로 조사되었다. 질산성 질소는 0.07-1.81 mg/L의 범위로 평균값은 0.85 mg/L로 나타났다. 염소이온는 0.07-59.07 mg/L의 범위로 평균 값은 8.54 mg/L로 나타났다. 페놀은 0.001-0.0049 mg/L의 범위로 평균값은 0.0026 mg/L로 나타났다. 납은 0.001-0.989 mg/L의 범위로 평균값은 0.019 mg/L로 나타났다. 6가 크롬은 0.0002-0.0482 mg/L의 범위로 평균값은 0.0176 mg/L로 나타났다. 그리고 나머지 카드뮴, 비소, TCE, PCE, 1.1.1-트리클로로에탄은 검출 한계미만으로 나타났고, 시안, 유기인, 수은은 불검출 되었다. 본 연구 결과 전라북도 동부 산악지역 농업용 대형관정의 지하수는 농업용수 기준 수치 이하로 조사되어 적합한 농업용수라고 판단된다. This study was carried out to investigate agriculture water quality for under ground well at eastern mountainous area in Jeollabuk-do. Samples were analyzed to contain general water quality index such as pH, NO₃-N, chloride ion, and pollutant material such as CN, organic phosphates, phenol, TCE(trichloroethylene), PCE(tetrachloroethylene), 1.1.1-trichloroethane, Cd, As, Hg, Pb, Cr⁺⁶, respectively. These analyzed data were compared with agricultural water quality standard. As a survey results, underground well at eastern mountainous area in Jeollabuk-do are below the agricultural water quality standard level, it is demonstrate that the groundwater is suit as agricultural water.

등기원인증서의 공증제 도입에 관한 연구

조재영(Cho JaeYoung) 한양법학회 2008 漢陽法學 Vol.24 No.-

The register system aim at stability and speedness on transaction of the right relation. In order to accomplish the role of register system, above all, our law would recognize the public trust in the registeration. Since our Civil law does not recognize any public trust to the registration of real estate right, the person who placed confidence in the registration and transacted the real estate falls a victim to unexpected loss. Under situation, This study will deal with the problems of a device of advanced public trust and improvement. Every issue was studied and analyzed through referring to the relevant documents about the civil law and the real estate registration law. I check the problems of methods to guarantee authenticity of registry, for instance, authentication of registry instruments, The scope of this study is confined to the real estate registration law. The foreign legislative examples on the register Notification are reserched. The French law and, German law and American law are analyzed relatively. In the end, I Investigated the problem of the Authentication of registry instruments and propose the recommendation of a means to vitalization of the Authentication record.

주식회사의 등기제도에 관한 문제점과 개선방안

조재영(Cho, JaeYoung) 한양법학회 2011 漢陽法學 Vol.34 No.-

The commercial registration is public announcement method providing certain information about the corporation. And the efficient corporation registration needs accuracy, clarity, and speed for public announcement function. Recently corporation registration needs increase greatly, due to the economic development and social change such as IT development in corporate environment and globalization. Therefore commercial registration law is established for more efficient management of the corporation registration. But connection relations of commercial law and commercial registration law were severed thus registration procedure has a problem of reguration shortage. For example, when a subsidiary corporation is established or a subsidiary corporation creates a new business, working guidelines or standards need to be presented since regulations are insufficient or unclear on changes in the mother company’s purpose, and procedures of debenture succession under formation of corporation following corporation division. This thesis points out issues and improvement and measures for settlement of such problems under our country’s corporation registration law.

불꽃점화엔진에서 잔류가스 내 화학종이 RON 100-에탄올표준연료의 노킹특성에 미치는 영향

조재영(Jaeyoung Cho),송한호(Han Ho Song) 한국자동차공학회 2018 한국자동차공학회 부문종합 학술대회 Vol.2018 No.6

폐기물연소기를 위한 물리모델기반 제어기개발

조재영(Jaeyoung Cho),송정우(Jeongwoo Song),이태경(Taekyung Lee),김용태(Yongtae Kim),송한호(Han Ho Song) 대한기계학회 2016 대한기계학회 춘추학술대회 Vol.2016 No.12

Waste incinerator is difficult to control since the composition of solid refused fuel (SRF) can change randomly under certain specification. In this study, a model-based controller was designed for waste incinerator and steam generator by using linear-quadratic regulator (LQR). Input variables were chosen as air and fuel supply rates, and output variables were steam flow rate and oxygen concentration of exhaust gas, thus requiring a multi-input multi-output (MIMO) control scheme. Control gain matrix was evaluated repeatedly at each time step based on nonlinear control model, which could predict the output variables covering the range of operations for the incinerator plant installed in Ul-San-Si. Then, the controller was applied to the developed plant model, which was validated with the experimental data of the designated plant. As a result, the disturbance on the system was effectively rejected, and steam production rate could be controlled to achieve the desired values.