• 한국소음진동공학회논문집
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• 제19권10호
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• pp.1062-1068
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• 2009

In this study, the impact force levels of bang machine and impact ball were measured, then the heavy-weight impact sounds generated by the bang machine and impact ball were investigated. It was found that the heavy-weight impact sources generated through modal excitation, and the impact force of the impact ball was similar to that of real impact source. The heavy-weight impact sounds were also measured in the real apartments with different slab thickness and floor structures. The results showed that the floor impact sound levels in terms of $L_{iFmax,AW}$, generated by impact ball sounds were reduced by using the resilient isolators. The frequency characteristics of heavy-weight impact sounds at 125 and 250 Hz were consistent with the characteristics of impact force spectrum. However, the difference between the impact sounds and the impact forces were found at 63 and 500 Hz due to the resonance of the floor structure and flanking noise, respectively.

• 디지털융복합연구
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• 제10권5호
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• pp.143-154
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• 2012

본 연구에서는 창업의도에 영향을 미치는 요인을 창업성과와 창업특성 요인들이 창업의도에 미치는 영향을 살펴보았다. 이 과정에서 창업특성 각 차원들이 창업의도에 미치는 영향에 대한 창업성과의 매개효과를 검정하고자 하였다. 실증결과 본 연구에서 사용된 창업특성과 창업성과가 창업의도에 유의한 정(+)의 영향을 알 수 있었다. 그리고 창업성과의 매개효과를 검증한 결과 창업성과는 매개효과가 있는 것으로 검정되었다. 이와 같은 결과는 창업성과에 대한 요인이 창업의도에 매출과 순이익이 영향을 미치는 것으로 나타났다. 특히, 창업특성인 성취욕구, 위험감수성, 사업전략이 창업의도 간의 영향관계를 확인하였다는 데 의의가 있다. 이 연구를 위하여 K공과대학교, K대학교, 대구 Y전문대학, J(사(社))직장인들을 대상으로 설문조사 및 연구결과를 도출하였다. 특히, 미 창업자들의 관점에서 창업특성, 창업성과, 창업의도에 대한 영향관계 확인에 시사점을 제공한다.

• 한국정밀공학회지
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• 제20권6호
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• pp.230-237
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• 2003

On this study, we operated the dynamic response for impact load of impact absorbing system for spreader by the finite element analysis and showed respectively the spring constant and the damping coefficient which the reaction force by impact was the lowest value for three types impact absorbing system according to the change of system, also we presented the change of impact reaction force according to the spring constant and the damping coefficient. Additionally, among the three types impact absorbing system according to the change of system, the reaction force of model II was the lowest value and the next model which has higher value than model II was model Iand model III has the highest value in the three types.

• The Journal of Asian Finance, Economics and Business
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• 제7권9호
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• pp.363-370
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• 2020

The paper aims to investigate the impact of budgetary goal on profit growth directly and indirectly through managerial performance. Two main characteristics of budgetary goal mentioning in the study are the clarity of budget goal and the difficult of budget goal. Data of the research collected from survey with 197 department managers and supervisors of 80 SMEs in Hanoi and Ho Chi Minh City who have budgeting responsible. Firstly, by using quantitative research method Cronbach's Alpha and Exploratory Factor Analysis, the research show that characteristic of budgetary goal has significant and positive impact on profit growth directly. Secondly, the regression analysis among variables show that budget goal clarity was positively and significantly related to growth of sale revenue, growth of profit and managerial performance. Therefore, the empirical findings show that that managerial performance has mediating role in the relationship between budgetary goal characteristic and financial performance. The findings of this study suggest that that managers need focus on setting clearer and more difficult but attainable budget goals to increase firm performance. This paper also provides a new insight the relationship between managerial performance and financial performance. Budgetary goal characteristics still have positive but insignificant impact on growth of sales revenue.

• 반도체디스플레이기술학회지
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• 제11권2호
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• pp.75-80
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• 2012

Polymer composites which have electrical properties have been studied in various industries. The Multi-walled carbon nanotube (MWCNT) are thought to be reinforcements for polymers because of their high aspect ratio and specially mechanical, thermal and electrical properties. We introduced MWCNT and impact modifier in order to improve thermal and mechanical properties of Polyphenylene sulfide (PPS) and give electric characteristic to PPS. The thermal properties were investigated by Differential scanning calorimeter (DSC) and Thermogravimetric analysis (TGA). The morphology, mechanical properties and electrical characteristic were performed by Field emission scanning electron microscopy (FE-SEM), Izod impact tester and surface resistance meter. As a result, we could find that the PPS/MWCNT composites have high conductivity and good mechanical properties than neat PPS resin.

• 한국기후변화학회지
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• 제6권2호
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• pp.121-131
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• 2015

As the temperature has changed by climate change, changes in its own characteristic values of the chemical substance or the movement and distribution of chemicals take place in accordance with the changes of hydrological and meteorological phenomena. Depending on the impact of climate change on the chemical behavior, it is necessary to understand and predict quantitative changes in the dynamics of the environment of pollutants due to climate change in order to predict in advance the occurrence of environmental disasters, and minimize the impact on the life and the environment after the incident. In this study, we have analysed and compared chemical fate models validated by previous studies in terms of model configuration, application size and input/output factors. The potential models applicable to municipal and industrial areas were selected on the basis of characteristic of each model, availability of input parameters and consideration for climate change, identified the problems, and then presented an approach to improve applicability.

• 한국항공우주학회지
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• 제49권7호
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• pp.549-555
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• 2021

원공이 있는 복합재 적층판의 강도는 복합재 항공기기 설계 시 충격하중이 가해지는 부위의 설계 허용치로 사용된다. 일반적으로 BVID (Barely Visible Impact Damage)에 의한 강도저하는 24.0 mm 폭의 시편에 6.0 mm 지름의 원공이 있는 시편의 강도로 가정한다. 본 연구에서는 원공이 있는 복합재 적층판의 강도에 적층각이 미치는 영향을 조사하기 위해 잔류강도 시험을 수행하였다. 원공이 있는 적층판의 강도를 예측하기 위해 특성길이를 이용한 점응력 파손기준을 사용하였고, 이론해를 검증하기 위하여 유한요소해석을 수행하였다. 실험결과로부터 특성길이는 0°, ±45°와 90°층의 비율과 관련이 있음을 보였다. 또한 회귀분석을 통하여 임의의 적층 패턴에 대한 특성길이와 원공이 없는 시편의 강도를 결정하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.121-121
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• 2000

This paper presents a design of macro-micro system for high-speed mounting of micro-chips. A macro motion device is driven by DC servomotor and ball screw mechanism. To obtain fast response, a micro motion device utilizes a precision elector magnetic actuator In order to reduce peak impact force, We evaluate the design parameters that have an effect on it. And a characteristic of response is simulated using PID controller in velocity and force control.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1996년도 특별강연 및 추계학술발표 개요집
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• pp.85-88
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• 1996

• 대한기계학회논문집A
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• 제22권4호
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• pp.826-833
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• 1998

The energy-absorbing characteristic of impact limiters affects the cask design so significantly that it should be evaluated as accurate as possible. The objective of this study is to find the influence of the impact limiter's steel case and gusset plates which enclose the shock absorbing cellular material on the impact energy absorption. The influence of impact limiter's steel case and gusset plate stiffeners on the impact energy absorption behavior under horizontal drop impact was evaluated for a radioactive isotope transport cask. Though the impact limiters mitigate the impact damage of the cask, the impact limiter's steel case and gusset plate stiffeners increase the impact force so significantly that should be designed as soft as possible. The impact analysis without considering impact limiter's steel case and gusset plates stiffener gives non-conservative results, so the stiffness of the steel case and gusset plates should be considered in impact analysis.