다양한 입력조건에서 에너지 하베스팅 현가장치의 발전량 민감도 분석

김태동(Taedong Kim),김진호(Jinho Kim),김지혜(Jihye Kim) 한국자동차공학회 2018 한국자동차공학회 학술대회 및 전시회 Vol.2018 No.11

블레이드를 통한 에너지 하베스팅 현가장치의 발전량 검증

김태동(Taedong Kim),김진호(Jinho Kim) 한국소음진동공학회 2019 한국소음진동공학회 학술대회논문집 Vol.2019 No.10

사용종료 비위생 매립 부지의 활용 방안 연구

김태동(Kim, Taedong),박종웅(Park, JongWoong),최동혁(Choi, Dong-Hyeog) 한국산학기술학회 2014 한국산학기술학회논문지 Vol.15 No.6

본 연구는 경북지역에 산재한 사용종료 비위생 매립 부지의 특성을 토대로 효율적인 부지 활용 방안 제시를 목적으로 하였다. 연구 대상 매립 부지의 활용성에 영향을 주는 인자를 선정하여 매립 부지의 유형을 분류함으로써 체계적인 활용 방안 선택의 기초 자료를 제공하였다. 매립 부지의 활용 인자로는 부지의 면적, 도로 이격 거리, 마을 이격 거리를 분석하였으 며 통계 분석을 통하여 대상 매립 부지의 유형을 결정짓는 주요 인자는 부지의 면적임을 알 수 있었다. 이러한 결과를 토대로 매립 부지의 특성에 알맞은 활용 방안 결정 지침을 제시하였다. The aim of this study was to suggest site-specific reuse alternatives for closed unsanitary landfills (CULs) scattered in Gyeongbuk Province. The CULs were classified with the factors affecting the site reuse alternative to provide basic data for systematic site reuse. Statistical analysis showed that the site area was the main factor in site classification among the site area, distance to road, and distance to the village. The results proposed a site-specific guide flow to the reuse of the CULs.

자기표현과 사회적 기대감이 지속적 사용에 미치는 영향

엄하정(Hajung Aum),장진규(Jinkyu Jang),김민지(Minji Kim),김태동(Taedong Kim),김현영(Hyunyoung Kim),김진우(Jinwoo Kim) 한국HCI학회 2014 한국HCI학회 학술대회 Vol.2014 No.12

사용자들의 콘텐츠 소비가 PC 에서 모바일로 이동함에 따라, 추천 서비스가 최근 각광을 받고 있다. 그러나 추천 서비스 내에서 사용자들이 평가 정보를 남기고 보는 순환적 흐름이 잘 이루어지지 않아 지속적인 서비스 사용이 이루어지지 않고 있다. 기존의 추천 서비스를 대상으로 한 연구에서는 서비스내 정보에 따른 사용자의 인지적 차이에 초점이 맞춰져 있을 뿐, 사용자들이 추천 서비스에서 지속적인 참여를 할 수 있게 만드는 인지적 기재에 대해서는 연구가 거의 없다. 이에 본 연구에서는 추천서비스의 지속적인 사용 요인이 무엇인지를 심층적 인터뷰를 통해 알아보고자 하였다. 특히 평가 정보를 남기는 사람의 측면에서 이를 살펴보고, 향후 사용자들이 추천 서비스에 지속적으로 참여할 수 있도록 하기 위한 실용적인 시스템 가이드를 제안하고자 한다. Tendency of accepting information based on recommendation system is arising on using of mobile devices. However, formal researches have focused on users’ cognitive differences based on information found in recommendation system and cognitive factor that makes users consistently participate in recommendation system is left unexplored. To overcome this limitation, we conducted indepth interview with a prototype we developed. The study aims to examine the positive effect of self-presentation and social-expectation on continuous usage, especially focusing on interpersonal interaction. As a result, we suggest practical guideline to induce users to continuously participate in recommendation system.

노동조합과 재무분석가 이익예측

손성규 ( Sungkyu Sohn ),김태동 ( Taedong Kim ),신일항 ( Ilhang Shin ) 한국회계학회 2016 회계저널 Vol.25 No.5

본 연구는 노동조합의 영향력이 재무분석가의 이익예측에 어떠한 영향을 미치는 지에 대해 분석하였다. 선행연구에 의하면, 노동조합이 존재하는 경우 경영자가 노사협상에서 우위를 점하고자 기업의 정보비대칭을 조장함으로써 재무분석가의 이익예측의 정확성을 감소시키는 원인으로 작용할 수 있는 반면에, 노동조합이 경영자의 행동을 모니터링하는 기업지배구조로서 작동하여 기업의 정보비대칭을 감소시켜 재무분석가의 이익예측의 정확성을 증가시킬 수도 있으므로, 노동조합이 재무분석가의 이익예측에 미치는 영향은 실증적인검증이 요구된다. 실증분석 결과, 노동조합이 존재하는 기업은 노동조합이 없는 기업에 비해 재무분석가의 이익예측 오차의 수준이 높았으나, 노동조합의 영향력의 대용치로 볼 수 있는 노동조합가입률은 재무분석가의 이익예측 오차의 수준에 통계적으로 유의한 영향을 미치지 않은 반면에 상급단체, 특히 민주노총에 가입해서 노동조합이 상급단체의 보호를 받는 경우 재무분석가의 이익예측 정확성이 통계적으로 유의하게 감소함을 확인하였다. 추가 분석을 통해, 재무분석가들의 이익예측치가 추후에 발표되는 기업의 실제 이익보다 더 높은 낙관적인 예측을 하는 추세가 노동조합의 영향력이 증가하면 더 뚜렷하게 나타난다는 사실을 확인하였다. 또한, 다양한 강건성 검증을 통해 상기의 실증 분석의 결과가 통계적으로 강건함을 확인하였다. 이러한 연구 결과는 노동조합의 존재가 자본시장의 정보비대칭을 증폭시켜 재무분석가 이익예측 특성으로 측정하는 회계정보의 유용성에 영향을 미치는데, 그 정도가 노동조합의 개별 기업수준의 가입률에 의해 상이해지는 것은 아니라 민주노총 같은 상급단체에 가입하여 해당 기업 노조가 보호받고 있는지 여부에 의해 상이해진다는 사실을 암시한다. 본 연구결과는 자본시장의 이해관계자들이 노동조합이 회계정보의 유용성에 미치는 영향을 이해하는데 필요한 시사점을 제공한다. This study examines the relationship between labor union and the characteristics of analysts forecasts. Specifically, we investigate whether the presence of union (bargaining power of unions) is related to the absolute error in analysts forecasts. A union tries to protect employee rights and improve employee welfare. Futhermore, a union tries to reflect its opinion in the process of decision-making for management. For example, Hyundai Heavy Industries`` labor union was known to demand for the right of recommendation for outside director reflecting its opinion. For that reason, managers have incentives to have good relationships with employees, because having non-cooperative labor can be detrimental (Hamm et al 2015). For example, as Hamm et al (2015) note, the United Airlines chapter of the Air Line Pilots Association requested the resignation of Glenn Tilton as CEO of the airline because of poor financial performance. More specifically, the United pilots created a web site that explained what they considered the failures of Tilton’s management. Therefore, the presence of unions might make managers’ incentives to have good relationships with employees even stronger and affect managerial behaviors, since, as Banning and Chiles (2007) note, unions alter the underlying employment relationship between employer and employee. Prior studies suggest two different perspectives on relation between labor union and the absolute error in analysts forecasts : On the one hand, when the bargaining power of unions increase, managers can increase information asymmetry in order to improve their negotiating position and this could leads to the increase in the absolute error in analysts forecasts. This perspective reflects that a union is a residual claimant (Ahn et al. 2011). In other words, this perspective stresses that unions, through collective bargaining, redistribute a larger portion of profits to their members and consequently decrease firm profitability. In other words, in a situation where the firm and the union share the profits, the union would attempt to maximize the utility of its members by increasing its share of the firm``s surplus. Therefore, firms with a unionized workforce should have an incentive to hide or misrepresent their true position to take advantage of the negotiation (Reynolds et al. 1998; Ahn et al. 2011). On the other hand, when the bargaining power of unions increase, managers also can decrease information asymmetry because labor unions play a role as a part of the mechanism of corporate governance and this could leads to the decrease in the absolute error in analysts forecasts. This view emphasizes that management can achieve effective labor-management cooperation and goal alignment with unions by sharing information (Palmer 1977; Foley and Maunders 1977 ; Ahn et al. 2011). However, there is little evidence regarding the relationship between strong organized labor forces and analysts’ earnings forecasts. Therefore, it is an empirical question whether labor unions increase(decrease) the absolute error in analysts forecasts. We try to tackle this issue in this study by focusing on the characteristics in analysts’ earnings forecasts. Financial analysts use accounting information reported in financial statements. Therefore, if financial statements are more useful by organized labor forces, then the financial analysts should provide more accurate and less biased earnings forecasts. Using 1,158 firm-year observations of listed companies in the manufacturing industry from 2003 to 2008 in Korea, this study suggests that unionized firms are, on average, related to higher absolute error in analysts forecasts compared to non unionized firms. When it comes to union’s bargaining power, this study suggests that the umbrella unions which belong to the nation``s two umbrella labor organizations - the Korea Confederation of Trade Unions (KCTU) and the Federation of Korea Trade Unions (FKTU) are, on average, related to higher absolute error in analysts forecasts compared to independent unionized firms, although unionization rate measured by proportion of workers that are union member is not related to absolute error in analysts forecasts. Specifically, this study suggests that the umbrella unions which belong to the Korea Confederation of Trade Unions (KCTU) are, on average, related to higher absolute error in analysts forecasts compared to the umbrella unions which belong to the Federation of Korea Trade Unions (FKTU). In addition, this study suggests that union’s bargaining power have positive impact on forecast optimism. We check the robustness of our results through a battery of robustness tests. This study makes contribution to the existing literature. To the best of our knowledge, this is the first study to focus on the relationship between labor union and the characteristics of analysts forecasts. This paper aims to enhance our understanding of the relationship between labor union and the usefulness of earnings information by providing fresh evidence that labor union significantly affects the characteristics of analysts forecasts.

전산유체역학을 이용한 스텐트 설계

서태원(Taewon Seo),김태동(Taedong Kim),Abdul Barakat 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.4

Numerical investigation has been made on the stent design to minimize the neointimal hyperplasia. Computational fluid dynamics is applied to investigate the flow distributions in the immediate vicinity of the given idealized stent implanted in the blood vessel. Parametric study on the variations of the number of stents, stent diameters, stent spacings and Reynolds numbers has been conducted using ax i-symmetric Navier-Stokes equations. An initial difficulty in the study is to determine the optimal stent design to understand the flow physics of the flow disturbance induced by stent. The size of recirculation zone around stent is depend on the stent diameter, number of stent wire and Reynolds number but is insensitive to the stent wire spacing.

비정상투자, 경영자 예측, 그리고 재무분석가의 역할

최수영(Suyoung Choi),김태동(Taedong Kim),고재민(Jaimin Goh) 한국경영학회 2015 經營學硏究 Vol.44 No.4

L-THIA를 이용한 길안유역 비점오염원의 공간적 분포 모의

전지홍 ( Jeon Ji-hong ),최동혁 ( Choi Donghyuk ),김태동 ( Kim Taedong ) 한국농공학회 2008 한국농공학회 학술대회초록집 Vol.2008 No.-

In this study, Long-Therm Hydrologic Impact Assessment (L-THIA) was applied at Gilan watershed located in Nackdong River Basin to analyzed spatial distribution of nonpoint source pollution. L-THIA employs CN method and EMCs coefficients to estimate surface runoff and non pointsource pollution. For the calibration of surface runoff, CN was optimized by SCE-UA technique which is one of the global optimization method and widely used to automatic calibration of hydrologic model. The results of model calibration based on observed data during 1991-2000 represented high model efficient with showing 0.66 of Nash-Sutcliff Coefficient (NSC). During the validation period (1981-1990), simulated monthly results is well matched with observed monthly runoff with showing 0.73. Therefore, calibrated L-THIA model can simulate well the hydrologic condition of Giland watershed. Based on calibrated CN value, L-THIA simulate average yearly surface runoff and nonpoint source pollution for 30years.

SATEEC을 이용한 임하호 유역의 토양유실분포 파악

전지홍 ( Jeon Ji-hong ),최동혁 ( Choi Donghyuk ),김태동 ( Kim Taedong ) 한국농공학회 2008 한국농공학회 학술대회초록집 Vol.2008 No.-

In this study, Sediment Assessment Tool for Effective Erosion Control (SATEEC) was applied to Imha watershed located in Nackdong River Basin to estimate amount of soil erosion and analyze spetial distribution of soil erosion. SATEEC model employs RUSLE method and is execuated based on GIS environment. R factor was achieved by rainfall data which was measured within watershed. K and C factor was generated by soil and landuse data, respectively. LS factor was generated automatically by SATEEC using DEM. P factor was generated with combination of agricultural land and slope which is driven by DEM. As a results of SATEEC application, total eroded soil was estimated as 10,716,533 ton/yr. As a results of analysis of spatial distribution, the highest density of soil erosion was occurred at 200203 and 200206 of standard unit boundary with showing about 114 ton/ha/yr and 125 ton/ha/yr, respectively. Overall, upstream boundary produced more soil erosion than downstream showing over 60ton/ha/yr.

SCE-UA 최적화 기법을 이용한 동천 유역의 장기유출량모의 및 토지이용별 CN값 고찰

전지홍 ( Jeon Ji-hong ),최동혁 ( Choi Donghyuk ),김태동 ( Kim Taedong ) 한국농공학회 2008 한국농공학회 학술대회초록집 Vol.2008 No.-

In this study, hydrologic calibration were automatically performed by L-THIA model linked with SCE-UA technique, which is one of the global optimization methods, at Dongchun watershed. L-THIA model can simulate surface runoff by SCS-CN method. The monthly simulated runoff was well matched with monthly observed runoff during 1991-2000, showing about 0.72 of Nach-Sutcliff Coefficient (NSC). The validation results also represented high model efficiency with showing about 0.82 of NSE value during 1981-1990. Optimized CN can represent well hydrologic condition of Dongchun watershed.