• Journal of the Korean Operations Research and Management Science Society
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• v.33 no.4
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• pp.13-30
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• 2008

We explore the determinants of long-term relationship between the buyer and the supplier to help suppliers develope a strategy to build long-term relationship with their buyers. Based upon an extensive literature review, we propose three droops of independent variables which may affect long-term relationship, including (a) environmental factors (product complexity, product importance, source dependence, price sensitivity), (b) relational factors(trust, commitment, satisfaction, intention of expansion), (c) operational performance(quality, delivery, cost capability, technical knowhow). The buyer's actual period of relationship with its main supplier is used as a dependent variable. Using hierarchical multiple regression analysis, we empirically test hypotheses, analysing a sample of 290 manufacturing firms in the U.S. The statistical results indicate that the buyer's source dependence, price sensitivity and the supplier's commitment play a significant role in establishing long-term relationship between the buyer and the supplier. However, the supplier's cost capability and technical knowhow in operational performance negatively affect long-term relationship in contrast with our hypotheses. Due to this controversial result, we divide the sample group Into dual sourcing and multiple sourcing environments and reconduct regression analysis in a post hoc manner. The findings show that the supplier's cost capability and technical knowhow are negatively associated with the length of relationship only in the multiple sourcing environment. The results may confirm that both parties' opportunistic behavior is more salient in the multiple sourcing environment than in the single sourcing environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.708-711
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• 2011

The Navy is in the process of developing a sonar-operation strategy to increase the effectiveness of underwater target seeking capability. HMS is the basic strategy to detect underwater targets. The advantages of HMS is that, it has a short preparation time to operate and can be always used regardless of sea conditions and weather. However, it is difficult to effectively detect underwater targets due to the interaction between marine environments and sonar-operations. During the research, the effectiveness of the HMS system's underwater target seeking capability was analyzed by integrating various search patterns and environment conditions into the simulation. In the simulation the ship target an evasive target within a set region. The simulation presented results for an effective searching methods of underwater targets. These research results can be used as foundation for advancing and improving the sonar operational tactics.

• Journal of Korea Water Resources Association
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• v.57 no.4
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• pp.249-261
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• 2024

Climate change has intensified the severity of extreme floods, presenting substantial challenges to dam management and operation. Traditionally, flood control strategies for dam operations have been based on theoretical scenarios, such as designed floods, without taking into account downstream conditions. However, in practice, managing floods involves operating dams based on climate forecasts. This strategy encounters challenges due to the limited predictability of climate forecasts, which in turn leads to uncertainty in decisionmaking among dam managers. This study proposes a flood control approach for dam operations that involves gradually increasing the outflow, considering the operational constraints and potential downstream damage, based on inflow data. The effectiveness of this method was assessed through simulation, employing both a designed flood and data from the most significant historical flood. The dam operation strategy for flood control presented in this study provides a framework for dam operators, facilitating consistent decisionmaking in flood management by integrating realistic dam operational conditions.

• The Journal of Korean Association of Computer Education
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• v.13 no.2
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• pp.1-14
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• 2010

Previous researches on the improvement of logical thinking in Informatics subject have used general logical thinking test and only limited improvement of logical thinking by programming learning result. In this study, the operational definition of the logical thinking in problem-solving process on Informatics education is different from the general logical thinking and the logical thinking of the other subjects. Firstly, we suggested the operational definition of components of logical thinking using the open questionnaire by expert and research team discussion. Also, we suggested the relationship between the operational definition and contents of the 'problem-solving methods and procedure' section in secondary Informatics subject. Finally, this study developed the evaluation contents based on the operational definition of components of logical thinking. The components of logical thinking which was required in problem-solving process on Informatics subject were ordering reasoning, propositional logic, controlling variables, combinatorial logic, proportional reasoning. We suggested the relationship between operational definition and problem-solving process and assessment of logical thinking in problem-solving process on Informatics subject. This paper will give meaningful insight to supply the guideline of the teaching strategy and evaluation methods for improving the logical thinking in Informatics education.

• Strategy21
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• s.45
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• pp.33-59
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• 2019

There have many research papers to see China's evolution of maritime strategy and naval modernization in terms of its naval mind-set. However, this article focuses on assessing how China uses its all sorts of maritime strength to achieve 'a building maritime great power.' The aim of the article is to introduce a new perspective to this debate by analysing China's diversified ma maritime capabilities and a new way of implementation in maritime security strategy. In recent years, China has been developing not only unpredictable maritime military capabilities but also maritime supporting forces - Coast Guard and Maritime Militia. And recently China adopted up-to-date operational concept aimed at gaining military superiority in Asia-Pacific waters. By taking salami slicing strategy, gray zone strategy and cabbage strategy, China has been trying to exercise surpassing influences in regional maritime area, also in western Pacific region. This article provides a stepping stone to comprehend the aspect of China's recent maritime strategic actions, especially in Yellow Sea. In conclusion, this article suggests some policy recommendations for countering China's coercive maritime strategy. First, Korea should make sure a strategic concept of maritime security, instead of land warfare focused strategic concept. Second, it is needed to set up suitable naval forces for actively responding to neighbor nation's offensive actions.

• Strategy21
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• s.45
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• pp.148-187
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• 2019

This paper is to analyse the necessity and development direction of the ROK's maritime security strategy white paper. To this end the paper is composed of 5 chapters titled introduction; the necessity of the ROK's maritime security strategy white paper; the ROK's actual situation in relation to maritime security strategy and cases of major advanced oceanic countries; the vision, goals, strategic tasks, and implementation system of the ROK's 'national maritime security strategy'; and conclusion. The achievement of the national marine strategic vision, such as the 'Ocean G5,' is of course possible when Korea can maintain and strengthen the maritime safety and maritime security of the people. The Sewol Ferry incident reminds us that we need a 'national maritime security strategy white paper' like the advanced marine countries. In order for the national maritime security strategy to be carried our efficiently, as in advanced oceanic countries, mere should be a dedicated department with sufficient authority and status to mobilize the cooperation of related organizations including naval-coastal cooperation. It would be good to set up a tentatively named Maritime Security Council, an organization of minister-level officials involved under the National Security Council, and an executive body composed of working-level officials from related ministries. In order to successfully carry out the national maritime security strategy for the maritime safety and maritime security of the people like the United States and the United Kingdom, we need to further strengthen our domestic cooperation and cooperation system, international cooperation, and maritime security. We have to promote the establishment and promotion of maritime security strategies by the Navy; strengthening the operational link between the Navy and the Coast Guard; strengthening the maritime surveillance capability at the national level, and promoting sharing with the private sector, etc.

• Smart Structures and Systems
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• v.6 no.5_6
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• pp.561-578
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• 2010

This study proposes a multi-level damage localization strategy to achieve an effective damage detection system for civil infrastructure systems based on wireless sensors. The proposed system is designed for use of distributed computation in a wireless sensor network (WSN). Modal identification is achieved using the frequency-domain decomposition (FDD) method and the peak-picking technique. The ASH (angle-between-string-and-horizon) and AS (axial strain) flexibility-based methods are employed for identifying and localizing damage. Fundamentally, the multi-level damage localization strategy does not activate all of the sensor nodes in the network at once. Instead, relatively few sensors are used to perform coarse-grained damage localization; if damage is detected, only those sensors in the potentially damaged regions are incrementally added to the network to perform finer-grained damage localization. In this way, many nodes are able to remain asleep for part or all of the multi-level interrogations, and thus the total energy cost is reduced considerably. In addition, a novel distributed computing strategy is also proposed to reduce the energy consumed in a sensor node, which distributes modal identification and damage detection tasks across a WSN and only allows small amount of useful intermediate results to be transmitted wirelessly. Computations are first performed on each leaf node independently, and the aggregated information is transmitted to one cluster head in each cluster. A second stage of computations are performed on each cluster head, and the identified operational deflection shapes and natural frequencies are transmitted to the base station of the WSN. The damage indicators are extracted at the base station. The proposed strategy yields a WSN-based SHM system which can effectively and automatically identify and localize damage, and is efficient in energy usage. The proposed strategy is validated using two illustrative numerical simulations and experimental validation is performed using a cantilevered beam.

• Maritime Security
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• v.2 no.1
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• pp.1-42
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• 2021

Controversy continues over the offensive nature of China's naval strategy to become a maritime power. Therefore, the purpose of this study is to identify the characteristics of China's naval strategy to become a maritime power by using the three elements of strategy and predict China's military actions in the future. For this purpose, research was conducted by considering the three elements of strategy and the distinct characteristics of naval strategy, and it was found that China's naval strategy was overall aggressive, but there was an imbalance in the pursuit of aggression between each strategic element. Offensive nature was prominent in terms of the methods, but there were limitations in the goals and means, such as the need to cooperate with neighboring countries to become a maritime power and the lack of military technology and operational continuity. The prospects for China's future military actions derived from the imbalance between these strategic elements are as follows. ① The risk of all-out military conflict with the US is low for now. ② China may use its naval power to force or cause limited military clashes against neighboring countries within the first island chain. ③ Accidental military conflicts with the US and neighboring countries may occur over naval confrontation over territorial disputes.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.950-955
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• 2004

In the manufacture of liquid crystal display devices, there is a strong demand for contactless glass plate handling devices that can manipulate a glass plate without contaminating or damaging it. To fulfill this requirement, an electrostatic transportation device for glass plates is proposed. This device can directly drive a glass plate and simultaneously provide contactless suspension by electrostatic forces. To accomplish these two functions, a feedback control strategy and the operational principle of an electrostatic induction motor are utilized. The stator possesses electrodes which exert electrostatic forces on the glass plate and are divided into a part responsible for suspension and one for transportation. To accomplish dynamic stability and a relatively fast suspension initiation time, the structure of the electrode for suspension possesses many boundaries over which potential differences are formed. In this paper, an electrode pattern suitable for the suspension of glass plates is described, followed by the structure of the transportation device and its operational principle. Experimental results show that the glass plate has been transported with a speed of approximately 25.6 mm/s while being suspended stably at a gap length of 0.3 mm.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.3 s.180
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• pp.76-85
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• 2006

In the manufacture of liquid crystal display devices, there is a strong demand for contactless glass panel handling devices that can manipulate a glass panel without contaminating or damaging it. To fulfill this requirement, an electrostatic transportation device for glass panels is proposed. This device can directly drive a glass panel and simultaneously provide contactless suspension by electrostatic forces. To accomplish these two functions, a feedback control strategy and the operational principle of an electrostatic induction motor are utilized. The stator possesses electrodes which exert electrostatic farces on the glass panel and are divided into a part responsible for suspension and one for transportation. To accomplish dynamic stability and a relatively fast suspension initiation time, the structure of the electrode for suspension possesses many boundaries over which potential differences are formed. In this paper, an electrode pattern suitable for the suspension of glass panels is described, followed by the structure of the transportation device and its operational principle. Experimental results show that the glass panel has been transported with a speed of approximately 25.6 mm/s while being suspended stably at a gap length of 0.3 mm.