• The Journal of the Korea Contents Association
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• v.16 no.1
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• pp.699-707
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• 2016

The purpose of this study, including the Korea stock market and neighboring countries markets is seeing a look at the correlation and synchronization phenomenon. For this purpose, which is expected to have an impact on Korea's stock market, selection the United States and China, Japan, Germany on behalf of the European analyzed the data of the last 151 months. Any analysis, Korea market appeared to show a high correlation with the synchronization phenomenon in Germany and the United States. However Korea and Japan exhibited a low correlation. While the US market showed a very high correlation with Germany but showed a low correlation with China. China has been judged by the proprietary market due to a low correlation with the United States and Japan. The Japanese market has been more affected in Germany and the United States than Asian markets. German market is analyzed to influence the US market under the influence of the Asian market.

• Structural Monitoring and Maintenance
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• v.9 no.2
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• pp.201-220
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• 2022

Lateral vibrations of footbridges may induce synchronization between pedestrians and structure itself, resulting in amplification of such vibrations, a phenomenon identified by lock-in. However, investigations about accelerations and frequencies of the structural movement that are related to the occurrence of synchronization are still incipient. The aim of this paper is to investigate conditions that could lead to avoidance of synchronization among pedestrians themselves and footbridge, expressed in terms of peak acceleration. The focus is on the low acceleration range, employed in some guidelines as a criterion to avoid synchronization. An experimental campaign was carried out, employing a prototype footbridge that was set into oscillatory motion through a pneumatic exciter controlled by a fuzzy system, with controlled frequency and amplitude. Test subjects were then asked to cross the oscillating structure, and accelerations were simultaneously recorded at the structure and at the subject's waist. Pattern and phase differences between these signals were analysed. The results showed that test subjects tended to keep their walking patterns without synchronization induced by the vibration of the structure, for structural peak acceleration values up to 0.18 m/s², when frequencies of oscillation were around 0.8 to 0.9 Hz. On the other hand, for frequencies of oscillation below 0.7 Hz, structural peak accelerations up to 0.30 m/s² did not induce synchronization.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.8
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• pp.998-1004
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• 2007

Connecting a synchronous generator to a power system is a dynamic process, requiring the coordinated operation of many components and systems. The goal is to connect the oncoming generator to the system smoothly i.e without causing any significant bumps, surges, or power swings, by closing the ACB when the oncoming generator matches the power system in voltage magnitude, phase angle, and frequency. If oncoming generator voltage is not matched to the power system voltage, reactive power will flow either into or out of the system at the instant of ACB closure. If this voltage difference is too great, the reactive power flow may result in high transient stresses that could damage the windings of the generator. Also, if oncoming generator frequency is not matched to the power system frequency, transient power will flow between generator and power system. If the frequency difference is too great, the transient power flow is reflected into the prime mover shaft, and this may result in excessive shaft or coupling stress. This paper tries to prove the necessity of correct synchronization for ship generators through a transient phenomenon analysis.

• The Korean Journal of Applied Statistics
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• v.23 no.3
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• pp.443-456
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• 2010

This study is an empirical research of the stock markets to prove the synchronization phenomenon of the world economy. For this research I analyzed Korea's KOSPI, USA's DOW & NASDAQ reflecting stock markets in North America, Japan's NIKKEI in Asia, and Germany's DAX in Europe. Because the raw series are not stationary, they are to be transformed to returns series. The results of the study are follows: First of all, there are significant causalities between KOSPI's returns and those of other indices. Second, feedback effects are found between the market returns with several time lags. Third, there are 4 cointegrating equations which embody the relation of the five returns series. And forth, KOSPI reacts more sensitively to impacts from the foreign indices compared to the other indices do when they got impacts from each other except KOSPI. On conclusion, there exists a clear evidence for the synchronization phenomenon in returns of the stock indices, and we can expect Korea market may get similar changes depending on the economic changes of North America, Europe, or Asia. Therefore more closing researches should be conducted about the world economy synchronization in various fields as soon as possible.

• Journal of the Korea Society of Computer and Information
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• v.6 no.4
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• pp.38-44
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• 2001

The integration of concurrency and object-oriented programming paradigm has been a goal of researchers for over a decade. The concurrent object-oriented programming languages used for various concurrent applications development. However, concurrency and inheritance have conflicting characteristics, thereby inhibiting their simultaneous use without heavy breakage of encapsulation. This conflicting phenomenon is known as inheritance anomalies, have been limited in applicability and have not addressed all the issues that synchronization raises. In this paper, the behavior description equation is introduced for the solution for the conflicting phenomenon, between inheritance and object-based concurrency. As a result, it can solve the several inheritance anomalies and is not necessary to redefine method. Therefor, it offers flexible concurrency model with an emphasis on the reuse of both synchronization and function code.

• Journal of Digital Convergence
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• v.18 no.2
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• pp.197-204
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• 2020

The purpose of this paper is to find the direction by analyzing the synchronization phenomenon and the change rate of apartment charter rate in Korea, Seoul, Busan, Daegu, Gwangju and Daejeon. For this purpose, this study used a total of 239 monthly data from January 2000 to November 2019 in Kookmin Bank housing statistics. In the correlation analysis, Korea showed the highest relationship in order of Seoul, Busan, Incheon and Daegu. Seoul showed a low figure of 0.3 without any distinctive features from other cities. On the other hand, Busan, Daejeon and Daegu showed high correlations. As a result of the regression analysis, Korea and 5 major cities were all moving in the same direction with positive(+) values. And Busan and Seoul responded significantly to Korea. In the shock response, Korea is most shocked by the change in Seoul. Daegu is relatively shocked by Busan and Daejeon. Seoul's charter rate has declined most strongly in the last three years. Therefore, it is time to be careful not to incur losses due to gap investment. If we look at the relationship between the charter rate and the sale price in future studies, we can better understand the Korean apartment market.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.159-162
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• 2005

Random Early Detection (RED), one of the most well-known Active Queue Management (AQM), has been designed to substitute Tail Drop and is nowadays widely implemented in commercially available routers. RED algorithm provides high throughput and low delay as well as a solution of global synchronization. However RED is sensitive to parameters setting, so the performance of RED, significantly depends on the fixed parameters. To solve this problem, the Adaptive RED (ARED) algorithm is suggested by S. Floyd. But, ARED also uses fixed parameters like target-queue length; it is hard to respond to bursty traffic actively. In this paper, we proposed AQM algorithm based on the variation of current queue length in order to improve adaptability about burst traffic. We measured performance of proposed algorithm through a throughput, marking-drop rate and bias phenomenon. In experimentation, we raised a packet throughput as reduced packet drop rate, and we confirmed to reduce a bias phenomenon about bursty traffic.

• IE interfaces
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• v.21 no.2
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• pp.161-169
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• 2008

Normally, suppliers have to decide on what, how much, and when to replenish stocks of goods based on a data flow generated by a vendor managed inventory(VMI) system. But information from supply chain is often misleading. It is common for such data to be distorted by a lack of coordination and synchronization across several business entities managing different supply chain operations. This phenomenon is called the 'bullwhip effect(BwE)'. Many researchers, working over many years, have studied the reasons for the BwE. They have proposed various remedies, but this phenomenon persists. Though overlooked in previous research, this paper reveals that the 'lot size' of a supply chain of distribution is indeed the main cause of the BwE. In addition, some problems in the existing methods of measuring the BwE are identified and a revised much improved method of measurement is suggested.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.701-704
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• 2001

Nowadays there are being done many researches on chaos phenomenon among an assortment of group. Currently, already many applications has been developed, applying this phenomenon to engineering problem. now we are to show how we achieved secure communication through hyperchaotic synchronization system using 1-dimensional CNN(Cellular Neural Network). we focused on materializing secure communication.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.705-708
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• 2001

Nowadays there are being done many researches on chaos phenomenon among many kinds of people. Currently, already many applications has been developed, and they applied this phenomenon to engineering problem. now we have tried to make it possible to use secure communication through hyperchaotic synchronization system using 1-dimensional CNN(Cellular Neural Network). we focused on materializing secure communication.