• International Commerce and Information Review
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• v.15 no.3
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• pp.3-24
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• 2013

This study has examined the relationship between entrepreneurial orientation(EO), dynamic capability(DC) and export performance of international new ventures(INVs). Also, the moderating effect of external environment factors(the hostility at domestic markets and the industrial dynamics) were analysed. Empirical analysis was performed on 101 INVs. It was conducted using the PLS(Partial Least Square). The result of empirical analysis showed that there is a positive relationship between EO, DC and export performance. The result of moderating effect showed that two external environment factors have positive moderating effect on the relationship between EO and DC. However, there was not moderating effect of external environment factors on the relationship between DC and export performance.

• Journal of IKEEE
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• v.15 no.1
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• pp.76-85
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• 2011

In this paper, we analysed RSS characteristics by external factors and presented an efficient algorithm for real-time location tracking and its hardware system. The proposed algorithm enhanced the ranging accuracy using Kalman Filter based on the RSS DB. The location tracking system that consists of the tag, AP(Access Point), a data collector(Data Receiver) with IEEE 802.15.4(ZigBee) network environment, and location tracking application that reveal locations of each tag is implemented for the test environment. The location tracking system presented in this paper is implemented with MSP430 microprocessor manufactured by TI(Texas Instrument), CC2420 RF chipset and the location tracking application. With the results of the experiment, the proposed algorithm and the system can achieve the efficiency and the accuracy of location tracking with the average error of 19.12cm, and its standard deviation of 5.31cm in outdoor circumstance. Also, the experimental result shows that exact tracking of position in indoor circumstance cannot achieve because of vulnerable RSS with external circumstance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1991.04a
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• pp.17-22
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• 1991

최근 기계장치로부터 발생하는 소음을 감소시키는 새로운 방법으로서, 능동 적으로 소음을 제어하는 방법에 대한 연구가 활발히 진행되고 있다. 이것은 원하지 않는 소음을 그 신호의 역위상을 갖는 부가음을 이용하여 능동적으 로 감쇠시키는 방법으로서, 저주파수 대역에서 비효율적인 수동적인 방법인 소음기둥에 대한 대안으로 많은 학자들의 관심의 대상이 되어 왔다. 초기에 는 소음을 줄이기 위해 요구되는 여러가지 음향요소의 전달함수를 제어하는 데 대한 불가능성으로 인해 능동 소음제어에 대한 실질적인 발전이 지연되 어 왔으나 최근 마이크로 컴퓨터를 비롯한 전자공학의 발전으로 인해 적응 신호처리 분야가 등장하게 되었으며, 음향계의 소음을 원하는 수준까지 제어 하는 능동 소음제어의 실시간 구현이 가능하게 되었다. 그 중에서도 음이 1 차원적으로 전파한다고 볼 수 있는 길이가 긴 덕트구조물에서의 능동 소음 제어는 가장 기본적이며 현실적으로 자동차 배기계나 냉동.공조설비에 있어 서 실용적으로 적용할 수 있는 문제임 만큼 많은 연구가 이루어지고 있다. 이러한 능동 소음제어 방법을 음향계에 적용하였을 때, 부가적인 음을 발생 하는 제어용 스피커로 인해 입력마이크로폰으로의 음향궤환이 존재하고 이 에 따라 제어계가 불안정해질 수 있으며, 또한 변환기의 사용으로 인한 부가 적인 전달함수가 존재하므로 이에 대한 중요한 의미를 갖고 고려하여야 한 다. 본 연구에서는 적응 필터링 이론에 의한 소음원의 입력신호에 대한 최적 한 예측으로써 부가음을 발생시키고, 입력신호 및 제어된 출력신호간의 차인 오차를 최소화 시키도록 하는 오차적응제어법을 이용한 능동소음 제어 방법 을 제시하였다. 이와 아울러 제어계의 환경변화에 따른 파라메타의 변화에 적응적으로 응답이 가능해야 하는 적응 소음제어 시스템에서, 음향궤환과 함 께 필히 고려해야 하는 부가적인 전달함수의 영향을 고려한 능동 소음제어 에 대해 연구하였다. 경량화 추세에 따라 지반이나 케이싱이 경량이거나 유연하여 회전축과 동적으로 연성된 경우 회전축-베어링-지반으로 이루어진 2중구조의 회전축 계 동특성을 해석할 수 있는 프로그램을 개발하므로서 회전 기계류의 진동 전반에 걸친 문제점에 대한 그 원인과 현상을 명확히 분석하여 국내의 전기 계류의 보다 신뢰성있는 설계 및 제작자료를 확보하는데 기여할 수 있게 하 였다.존의 small molecular Gd-chelate에 비해 매우 큼을 알 수 있었다. MnPC는 간세포에 흡수된 후 담도계로 배출되는 간특이성 조영제임을 확인하였다. 장비 내에서 반복 시행한 평균값의 차이는 대체적으로 유의한 차이가 없었으나, 다른 장비에서 반복 시행한 장비간의 사이에는 유의한 차이가 있는 경우가 더 많았다. 따라서 , MRS 검사를 소뇌나 뇌교의 어떤 절환에 적용하기 전에 각 장비 마다 정상 기준치를 반드시 얻은 후에 이상여부를 판 정하는 것이 필수적이라고 생각된다.EX> 이상이 적절한 진단기준으로 생각되었다. $0.4{\;}\textrm{cm}^3$ 이상의 좌우 부피차를 보이는 모든 증례에서 육안적으로도 해마위축이 뚜렷이 나타났다. 결론 : MR영상을 이용한 해마의 부피측정은 해마경화증 환자의 진단에 있어 육안적인 MR 진단이 어려운 제한된 경우에만 실제적 도움을 줄 수 있는 보조적인 방법으로 생각된다.ofile whereas relaxivity at high field is not affected by τS. On the other hand, the change in τV does not affect low field profile but strongly in fluences on both inflection fie이 and the maximum relaxivity value. The results shows a fluences on both inflection field

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.3
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• pp.234-240
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• 2002

The static stability of the otter board in relation to the angle of attack ($\alpha$) was studied analytically and experimentally from the moments of tensions and hydrodynamic force acting on it. Three flat plates of 0.5, 1.0, and 1.5 aspect ratios (λ) and four cambered plates of 5, 10, 15, and 20% camber ratios (CR) with the same aspect ratio (λ=1.5) were tested in a circulating water tank for measuring the hydrodynamic forces and moments relevant to the position of hydrodynamic center. And, center-of-pressure coefficients ($C_p$) and moment coefficients ($C_M$) of each plate as a function of the angle of attack were calculated for estimating the static stability from hydrodynamic forces. The obtained results are summarized as follows ； 1． When the angle of attack for otter board is changed from equilibrium for some reason, moments depending upon tensions of warp and sweep line always act in order to have the static stability, respectively. 2. Position of center-of-pressure of each flat plate moves from leading edge to center of plate with the increase of the angle of attack. It means that the moment of hydrodynamic force acting on flat plates also increases the static stability of plate. 3. With the increase of the angle of attack for cambered plates, the positions of center of-pressure move from trailing to leading edge, and then turn toward center of plate. As the camber ratios increase, the ranges of the angle of attack of the static un stability depending on moment of hydrodynamic force become wide.

• Korean Journal of Social Welfare
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• v.37
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• pp.143-169
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• 1999

The problems of unemployment have been recognized as male problems even though the female unemployment problems are as significant as those of men since IMF. The women who have experienced insecure employment and lower wage than men in the labor market are having more serious economic difficulties after being unemployed. Especially economic problems of the unemployed female headed families are anticipated to be tremendous because the female heads do not have spouses who can act as a buffer seeking or beginning to work to reduce economic hardship. The purpose of this paper is to compare living conditions and utilization of the unemployment programs between male and female heads of the family who are unemployed and discouraged workers. It will examine the functionalism, human capital theory, and feminist perspectives on the cause of female unemployment in order to help understanding of their living situations after being unemployed. Then, it will compare the socio-demographic characteristics, their economic activities before being unemployed, their living conditions and changes in family life after being unemployed, their efforts to overcome unemployment and utilization of various government unemployment programs. It used the national data of National Unemployment Survey of Korean Institute of Health and Social Affairs conducted in 1998 and analyzed 283 female and 1,528 male family heads who are unemployed and discouraged workers. It reveals that the female family heads experienced lower economic status in the labor market before being unemployed, are having more serious economic hardship because of it, utilize more of the government programs such as public work and public assistance than the male family heads but less of the public loans for the unemployed. It recommends expansion of public work and public assistance, more vigorous advertisement of various unemployment programs, and active training of job creation technique for female family heads.

• Journal of Distribution Science
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• v.7 no.2
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• pp.5-28
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• 2009

As a result of this study only a few Korean firms have a certain management methods designed to predict the possibility of risk occurrence and establishment of systematic countermeasure. Besides, the Korean firms do not have enough data on the risk of Chinese Market. The risk management department inside the firm does not function efficiently, and when it comes to investigation of risk, it heavily depends on that of local branches. Accordingly, in order to accurately recognize and manage, the firms need to not only specialize risk management department but also outsource by using a consulting firm.

• The Journal of Engineering Geology
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• v.20 no.1
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• pp.47-60
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• 2010

This study is focused on the analysis of tunnel behavior to estimate the stability on tunnel design. An estimation method was proposed as a hybrid consideration, which contains the displacement analysis by 3D numerical simulation, the maximum displacement obtained after field measurement, and an assessment of tunnel stability using a deformation analysis proposed by Sakurai(1988, 1997). The points of case study by Sakurai(1988, 1997) were replotted considering his analysis. From the new analysis of the tunnel case study, the trend line for analyzed points is analogized, which curve is divided into stable, unstable and failure zone. To evaluate the estimation method, a special shape of railway tunnel was selected, which are the Inchon international airport rail way connected to subway line 9 in Gimpo, Korea. The point s of upper and below track on the Inchon international airport rail way were satisfied to the stability of tunnel after reinforcing. Also the points shows the higher apparent Young's modulus, which resulted from improvement on shear strength by the micro silica grouting and the supporting of umbrella method. Therefore, if new analysis used, proper tunnel reinforcing method could be selected according to tunnel strain and geological property.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.4
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• pp.343-351
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• 2016

Cryogenic spray characteristics of a nitrogen swirl injector operating in supercritical environment have been numerically investigated. By comparing the equation of states(EOS) used for supercritical condition, SRK EOS was applied to predict the nitrogen thermodynamic property under supercritical environment. A Chung's method was implemented for the calculation of viscosity and conductivity and Takahashi's correlation based on Fuller's Theorem was implemented for the calculation of diffusion coefficient. By injecting the nitrogen with 5 bar differential pressure into 50 bar chamber filled with nitrogen, numerical simulation has been conducted. The dynamic Smagorinsky sub-grid scale (SGS) model has been compared with the algebraic Smagorinsky SGS model using FFT frequency analysis. The instability at the liquid film and gas core inside injector and the propagation of pressure oscillation into the injector has been investigated. The spreading angle of swirl injector obtained by numerical calculation has been validated with experimental result.

• Journal of Bio-Environment Control
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• v.15 no.2
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• pp.138-148
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• 2006

This study was carried out to evaluate the structural safety fur both the attached wind-protecting wall in greenhouse and the detached one installed outside. Regarding the attached wind-protecting wall in greenhouse, the analysis was conducted by doing a fluid-structure coupled field analysis using both CFX-5.7 and ANSYS 8.1 and also under the design condition of an instantaneous maximum wind velocity of $30.9m{\cdot}s^{-1}$. Three kinds of the width ranged from 30 to 90cm were considered in this study. With regard to the detached wind-protecting wall, the structural saffty was analyzed under the pressure difference of 1,117 Pa which corresponded to a wind velocity of $50m{\cdot}s^{-1}$ and the analytical results were also compared with theoretical ones. The result showed that there was little difference in the distribution of velocity overall and total pressure on the lateral side according to the width of the attached wind-protecting wall, but greenhouse with wind-protecting widths of 30 to 60cm has been reinforced to the extent of about 11% when compared with the case of being without the wall. The result also showed that the detached wind-protecting wall with a main-column interval of 3m was not stable so that it was necessary for the detached wind-protecting wall to be adequately reinforced to secure structural stability. Finally, there was great difference between analytical results and theoretical studies. The difference meant that there was some possibility of including errors when a theoretical study was done in three dimensional structure.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.4
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• pp.10-18
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• 2018

The primary purposes of this study are to understand a fundamental aspect of current uniformity around a reinforcing bar (rebar) in cement mortar, and to develop an accurate monitoring method in a wet-dry cycling process with the alternative current (AC) impedance method. Three cement mortar specimens with two embedded rebars were prepared in the laboratory. As a main variable, the distance between two rebars was designed to be 10, 20 and 30 mm with the same thickness of 20 mm. To simulate the corrosion of rebars in concrete structures in a marine environment, three cement mortar specimens were exposed to 15 wet-drying cycles (24-hour-immersion in seawater and 48-hour-drying in a room temperature) in the laboratory. It was observed that the potential level shifted to a noble value during corrosion potential monitoring, which is attributed to acceleration of dissolved oxygen diffusion at the drying process. AC impedance was measured in a frequency range from 100 kHz to 1 mHz on a wet-drying process. A theoretical model was proposed to explain the interface condition between the rebars and cement mortar by using the equivalent circuit consisting of a solution resistance, a charge transfer resistance and a CPE (constant phase element). It was observed that the diffusion impedance appeared in a low frequency range as corrosion of rebars progresses. At the drying stage of the wet-drying cycles, the currents line for monitoring tended to be non-uniform at the interface of rebar/mortar, being phase shift, ${\theta}$, close to $-45^{\circ}$.