• Journal of the Earthquake Engineering Society of Korea
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• v.3 no.4
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• pp.11-22
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• 1999

In this study, the validity of the currently used seismic regulations for seismic isolated building structures is investigated, and a new formula for vertical distribution of seismic load is proposed. The distribution formula in UBC-91 did not provide sufficient safety, and thus revised in 1994. However it is pointed out that the revised formula overestimates the seismic load because of its similarity to that of the fixed-base structure. Therefore, in the proposed approach, it is intended to satisfy safety, economy, and applicability by combining the mode shapes of the seismic isolated structure idealized as two degrees of freedom system and those of fixed-base structure. For verification of the proposed formula, both a moment resisting frame and a shear wall system are analyzed. The results obtained from the proposed method turn out to be close to the results from a dynamic analysis.

• Korean Journal of Social Welfare
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• v.39
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• pp.210-237
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• 1999

The primary purpose of this study is to empirically examine the determinants of reemployment of the unemployed after the crash of Korea's economy in 1997. This study also investigates the effects of the government unemployment programs on reemployment of the program beneficiaries. Using the data from the 1998 Survey on Unemployment Condition and Welfare Needs, co-directed by the Korea Institute of Health and Welfare and the Korea Institute of Labor Policy, a Cox regression analysis was conducted. The study results suggested that, in general, the government unemployment programs did not have noticeable effects on reemployment of the beneficiaries. The study, however, found that the effect of the government programs varied, depending on the mode of unemployment-exit, that is, full-time versus part-time reemployment. In addition, the effects of such factors on reemployment as socio-economic characteristics of the unemployed, characteristics of households with unemployed family members, and previous job characteristics are also examined. Based on the study findings, some policy implications are discussed, and suggestions are made for improving the current unemployment programs.

• Journal of the Korea Convergence Society
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• v.9 no.9
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• pp.47-52
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• 2018

Wi-Fi enabled Internet of Things (IoTs) had a substantial impact on society, economy and industry. However wireless connectivity technologies in unlicensed band such as Wi-Fi are vulnerable to interferences. They also face difficulty providing wireless connectivity over long range in dense networks due to the dynamically changed interference effect and asymmetric interference conditions. In this paper, robust acknowledgement transmission scheme is proposed for long range IoTs. According to the proposed scheme, it is possible to control the transmission rate of the transmission success rate of the response frame by adjusting the transmission rate of the response frame when the interference is present asymmetrically. It is also possible to use higher data rate when high quality link is guaranteed. The evaluation results demonstrated the proposed scheme improves the aggregate throughput by at most 9 Mbps when 20 MHz bandwidth transmission mode was adopted.

• Proceedings of the Korea Contents Association Conference
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• 2005.05a
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• pp.172-177
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• 2005

Comics and animation have come to establish their position firmly as a genre of mass media, coming in and out freely in various areas, such as politics, economy, philosophy, education, religion, beyond the limit of amusement which was view point before. Moreover, at about 140 universities all over S. korea, they have established the subject related to comics and animation. And they have educated professional workers positively. Even at elementary schools, middle schools and high schools, they have early education courses for some students' special ability.(those are a kind of special extra classes). It is demanded to develop teaching system in the area of academic theories which pay an important part to quality improvement by recognizing this social atmosphere, in order to educate more efficiently for comics and animation. The aim of this study is to develop teaching system with mutual application of comics and animation ,which have each original mode of expression, using one methodology.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.2
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• pp.123-134
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• 2012

A typical cooling system of an engine relies on a water pump that circulates the coolant through the system. The pump is typically driven by the crankshaft through a mechanical link with engine starting. In order to reduce the friction and warm-up time of an engine, the clutch-type water pump (CWP) was applied in 2.0 liter diesel vehicle. The clutch-type water pump can force cooling water to supply into an engine by the operation of an electromagnetic clutch equipped as the inner part of pump system. The onset of CWP is decided by temperature of cooling water and engine oil. And, the control logic for an optimal operation of the clutch-type water pump was developed and applied in engine and vehicle tests. In this study, the warm-up time was measured with the conventional water pump and clutch-type water pump in engine tests. And the emission and the fuel consumption were evaluated under NEDC mode in vehicle tests. Also, tests were carried out for the various temperature conditions starting the operation of CWP. From the results of the study, the application of CWP can improve the fuel consumption and $CO_2$ reduction by about 3%.

• Journal of the Korea Society of Computer and Information
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• v.12 no.5
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• pp.273-284
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• 2007

This paper studies a periodic review inventory model with an e-MarketPlace transaction in reconfigurable manufacturing system(RMS). A decision maker can expand/reduce production capacity/quantities and/or replenish/dispose inventories from/to e-MarketPlace urgently to satisfy the stochastic demands. If inventories are replenished or disposed through e-MarketPlace, this leadtime is shorter than the production leadtime, but unit purchasing or selling cost is more expensive than that of expanding capacity or reducing production quantities respectively. Henceforth, trade-off on these alternatives is considered. In addition to this, in order to consider the economy of scale, our model includes the fixed cost for purchasing from e-MarketPlace and capacity expansion. We use dynamic programming and K convexity methods to characterize the nature of the optimal policy. Finally, We present the optimal inventory control policy which is composed by the combinations of a base stock and (s,S) type policy.

• Korea and Global Affairs
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• v.3 no.2
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• pp.131-154
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• 2019

The state behavior has a strong consequence with the national strategic culture. However, different scholars hold different views on the classification of the national strategic culture. As one of the most significant land neighbors in West China, Pakistan is China's all-weather strategic cooperative partner. Understanding Pakistan's strategic culture will not only help understand Pakistan's national policies and state behavior, but also help deepen China-Pakistan cooperation. Cutting in from the perspectives of geography, social economy, culture, history and military, the author believes that the formation mechanism of Pakistan's strategic culture is mainly affected by the following four factors: geopolitical environment, production mode and lifestyle, cultural tradition, historical experience and diplomatic relations. The analysis has found that Pakistan's strategic culture has been shaped by Islam and can be classified as an outward-oriented strategic culture, the state behavior also shows a strong Islamic identity.

• Journal of Korea Trade
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• v.23 no.8
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• pp.1-26
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• 2019

Purpose - This paper investigates the recent trade collapse, recovery, and prolonged slowdown to shed light on the discussions about whether the current slowdown is structural or cyclical. I examine structural, cyclical, and heterogeneous aspects of the recent trade trends using detailed statistics of a small open economy, South Korea, whose economic success and growth have been heavily dependent on exports. Design/methodology - I use both aggregated and disaggregated trade statistics of South Korea. I apply the following methodologies: 1) I decompose the trade growth into the extensive and the intensive margin and observe the effect of prices over time. 2) I estimate the trade-income elasticities focusing on the world's import demand, separately for goods from the world and from Korea. 3) I compare the drop in goods exports in slowdown and trade collapse, which are the two unusual periods in the recent history when world trade has substantially dropped altogether. Findings - I show that while the last drop of trade after 2015 has cyclical aspects, there is evidence that the continued slowdown from 2012 is structural: 1) the so-called 'China factor' is found in the analysis of trade-income elasticity of the world and China for imports from Korea. 2) The bilateral trade barriers between Korea and its principal trading partners are universally tightening. 3) Firm sizes, destination countries, and the mode of transactions affect disaggregated trade flows during the slowdown periods. Originality/value - This paper contributes to the debate regarding whether the current trade slowdown is structural or cyclical. I provide two concrete evidence that the export drop in 2015 stems from low oil prices: one is the divergence of Korean export value index from its export quantity index, which started in late 2014 when oil prices plunged. I also contribute to the literature by providing evidence that Korea's trade barriers with important trading partners are steadily increasing since 2012 as the protectionist measures toward Korea's export products are steeply increasing after the global financial crisis.

• Asia-Pacific Journal of Business
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• v.12 no.2
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• pp.175-186
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• 2021

Purpose - This study intended to identify the effects of varied institutional systems and policies that regulate or define operations of enterprises upon the profitability of private enterprises through case analysis. Design/methodology/approach - The systems and differences in the institution and commodity distribution in Korea and Japan, which define the operation of the "Garak Wholesale Market" and "Ota Wholesale Market". We were examined in the presentthis study, and the statistical data pertinent to the trade volume and profitability of wholesale market corporations that substantially run both markets, were analyzed. Findings - The competition among the corporations that run the "Garak Wholesale Market" substantially is limited due to regulations over the mode of transaction and monopoly of trust thereby significantly higher level of profitability and safety are guaranteed. However, the institutional autonomy that enabled each distributor in the "Ota Wholesale Market" to compete with each other freely caused the distributors therein face difficulties in securing stable profits due to the relatively poor level of profitability resulted from the autonomy. Research implications or Originality - It seems the autonomy in commercial transaction in the "Garak Wholesale Market" in Korea needs to be secured to promote the competition of distributors therein through an amelioration of institutional systems and amendment of relevant laws that prescribe current management of various distributors/operators in the market.

• Structural Engineering and Mechanics
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• v.87 no.2
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• pp.137-149
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• 2023

In this study, to explore the working performance of the CFST split spherical node wind power tower, two groups of CFST split spherical joint plane towers with different web wall thicknesses and a set of space systems were analyzed. The tower was subjected to a low-cycle repeated load test, and the hysteresis and skeleton curves were analyzed. ABAQUS finite element simulation was used for verification and comparison, and on this basis parameter expansion analysis was carried out. The results show that the failure mode of the wind power tower was divided into weld tear damage between belly bar, high strength bolt thread damage and belly rod flexion damage. In addition, increasing the wall thickness of the web member could render the hysteresis curve fuller. Finally, the bearing capacity of the separated spherical node wind power tower was high, but its plastic deformation ability was poor. The ultimate bearing capacity and ductility coefficient of the simulated specimens are positively correlated with web diameter ratio and web column stiffness ratio. When the diameter ratio of the web member was greater than 0.13, or the stiffness ratio γ of the web member to the column was greater than 0.022, the increase of the ultimate bearing capacity and ductility coefficient decreased significantly. In order to maximize the overall mechanical performance of the tower and improve its economy, it was suggested that the diameter ratio of the ventral rod be 0.11-0.13, while the stiffness ratio γ should be 0.02-0.022.