• International Area Studies Review
• /
• v.15 no.3
• /
• pp.175-188
• /
• 2011

This study aims to examine how the U.S. economic shocks affect the Japanese economy. It is widely believed that the U.S. economy has a significant effect on the Japanese economy. Actually, the U.S. accounts for a considerable amount of Japan's exports and imports. To the economic policymakers, it is very important to know how economic disturbances generated by the U.S. are transmitted to the Japanese economy. A vector autoregression(VAR) model is employed to investigate the international transmission channel of economic disturbances. The interactions of the U.S.-Japansese economy are investigated by using variance decompositions(VDCs). The results of this study provided the evidence that the U.S. economic shocks were important for the Japanese economy during the sample period. This study supports the notion of economic dependence of smaller open economy such as Japan as compared with larger economy such as the U.S.

• Journal of Korea Port Economic Association
• /
• v.20 no.1
• /
• pp.43-55
• /
• 2004

This paper investigates how Japanese economic shocks affect the Korean economy and analyzes the channels through which they are transmitted. Also, the relative importance of domestic and foreign shocks on the dynamics of certain key macro variables is investigated. The techniques of vector autoregression (VAR) are employed to investigate the international transmission of economic disturbances. The VAR methodology is a particularly useful means for characterizing the dynamic relationships among economic variables without imposing certain types of theoretical restrictions. The dynamic effects of Japanese economic shocks on the Korean economy are evaluated by estimating variance decompositions (VDCs) and impulse response functions (IRFs). This study supports the notion of economic dependence of a small open economy such as Korea to a large economy such as Japan.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.17 no.8
• /
• pp.757-765
• /
• 2007

Enhanced PSPICE circuit model for vented-box loudspeaker system with lumped parameters was proposed to more accurately simulate real vented-box loudspeaker system. Frequency dependent parameters were used to model voice coil inductor. Acoustic pressure response curves and electrical impedance curves were simulated and investigated by PSPICE circuit model according to circuit parameters' variations. Finally, it was used to identify faults detection in woofers manufactured by unskilled persons.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.17 no.10
• /
• pp.983-992
• /
• 2007

It was proposed to identify Thiele Small Parameters for loudspeaker attached to closed-box using known dynamic mass of moving parts. Also, enhanced PSPICE circuit model for closed-box loudspeaker system was proposed to more accurately simulate real closed-box loudspeaker system. Frequency dependent parameters were used to model voice coil inductor. Acoustic pressure response curves and electrical impedance curves were simulated and investigated by PSPICE circuit model according to compensation filter's parameters. Finally, proposed method is expected to be utilized for identification of pseudo Thiele Small parameters of microspeaker.

• Journal of Agricultural Extension & Community Development
• /
• v.26 no.2
• /
• pp.57-68
• /
• 2019

This paper was done as an exploratory study aiming to identify the relationship between small group characteristic factors and perceived performance in the Village Development Committee (VDC) in Saemaul Undong project in Laos. The data were gathered from 166 members in 17 VDCs in Vientian province, however 135 questionnaires were used in analysis. Structure Equation Model was applied in the analysis with Amos 21. The major finding of this study were as follows; firstly decision making was more influenced by task cohesion than social cohesion, secondly organizational citizen behavior was influenced by both task cohesion and social cohesion. However, social cohesion had more influence than task cohesion, thirdly the VDC members learned their technical knowledge from decision-making process, and influenced to their perceived performance level and to VDC sustainablity, and fourthly in overall, committee members implemented their jobs based on task-oriented.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.39 no.5
• /
• pp.31-40
• /
• 2002

We propose a novel ultra-short asymmetric vertical directional coupler switch (VDCS) with high extinction ratios larger than 30㏈ composed of switching operation induced section (SOIS), extinction ratio adjusted section (ERAS), and extinction ratio enhanced section (ERES). In this VDCSs, switching operation is achieved by changing the refractive index of one core in SOIS. The improvement of extinction ratios larger than 30㏈ for both cross and bar states is achieved by controlling the asymmetry of refractive indices between both cores in ERES. After propagating through ERAS with symmetry in the structure, different extinction ratios between cross and bar states at the end of SOIS are changed to the same value. For this reason, the optimum asymmetry of the refractive indices of cores to have the maximum extinction ratios and the lengths of ERES are the same for cross and bar states. Design guidelines to achieve high extinction ratios with large tolerances are presented.

• Development and Reproduction
• /
• v.24 no.4
• /
• pp.297-306
• /
• 2020

Repetitive changes in the intracellular calcium concentration ([Ca²⁺]i) triggers egg activation, including cortical granule exocytosis, resumption of second meiosis, block to polyspermy, and initiating embryonic development. [Ca²⁺]i oscillations that continue for several hours, are required for the early events of egg activation and possibly connected to further development to the blastocyst stage. The sources of Ca²⁺ ion elevation during [Ca²⁺]i oscillations are Ca²⁺ release from endoplasmic reticulum through inositol 1,4,5 tri-phosphate receptor and Ca²⁺ ion influx through Ca²⁺ channel on the plasma membrane. Ca²⁺ channels have been characterized into voltage-dependent Ca²⁺ channels (VDCCs), ligand-gated Ca²⁺ channel, and leak-channel. VDCCs expressed on muscle cell or neuron is specified into L, T, N, P, Q, and R type VDCs by their activation threshold or their sensitivity to peptide toxins isolated from cone snails and spiders. The present study was aimed to investigate the localization pattern of N and P/Q type voltage-dependent calcium channels in mouse eggs and the role in fertilization. [Ca²⁺]i oscillation was observed in a Ca²⁺ contained medium with sperm factor or adenophostin A injection but disappeared in Ca²⁺ free medium. Ca²⁺ influx was decreased by Lat A. N-VDCC specific inhibitor, ω-Conotoxin CVIIA induced abnormal [Ca²⁺]i oscillation profiles in SrCl₂ treatment. N or P/Q type VDC were distributed on the plasma membrane in cortical cluster form, not in the cytoplasm. Ca²⁺ influx is essential for [Ca²⁺]i oscillation during mammalian fertilization. This Ca²⁺ influx might be controlled through the N or P/Q type VDCCs. Abnormal VDCCs expression of eggs could be tested in fertilization failure or low fertilization eggs in subfertility women.