• Proceedings of the Korea Society of Design Studies Conference
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• 1995.11a
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• pp.40-41
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• 1995

• Journal of the Korean Operations Research and Management Science Society
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• v.20 no.2
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• pp.139-158
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• 1995

A temporal database systems provides timing information and maintains history of data compared to the conventional database system. In this paper, we present a temporal relational database which use an interval-stamping method for instant-based events and for interval-based states. A set of temporal algebraic operators are developed on an instance of time and interval of time so that we can manipulate events and states at a same time. The set of operation is the basis for creating a relational algebra that is closed for temporal relations. And temporal SQL is also suggested as a temporal query relational language for our algebraic operations on temporal relations.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1991.10a
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• pp.311-311
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• 1991

• Strategy21
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• s.38
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• pp.287-320
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• 2015

On October 27, 2015, USS Lassen(DDG82), a 9,200 ton class Aegis destroyer of the United States Navy, began its operations within 12 nautical miles of Subi Reef, one of the seven artificial islands that China has built and claimed sovereignty over. The maneuver was joined by anti-submarine patrol airplanes such as P-8A and P-3. The White House press secretary mentioned that the President of the United States approved the operation. In response, China announced that it warned the US Navy ship about the 'illegal violation' by sending two destroyers(PLAN Lanzhou and Taizhou). This event represents a close call case where tension between the United States and China in the South China Sea might have been elevated to a conflict between the two navies. Moreover, considering that this happened only one month after Chinese president Xi's state visit to the United States, the event shows that the positions of the two countries have become starkly different to the extent that they are so hard to be reconciled. The United States' position is different from those of Vietnam and the Philippines. Countries like Vietnam and the Philippines have been directly involved in disputes with regard to sovereignty claims across the waters in the South China sea. As for the United States, being a third party in the disputes, it still cannot be a by-stander watching the whole waters in the region fall under the influence of China. Accordingly, the United States maintains that all countries bear the rights of innocent passage and military operations in the Exclusive Economic Zones(EEZ) as stipulated by the United Nations Convention on the Law of the Sea(UNCLOS). In contrast, China claims that, historically, the South China sea has been part of China's territorial waters, and that foreign countries are not allowed to conduct military operations within the waters. It strongly accuses that such military operations are illegal. Against this background, this paper tracks the different positions of the United States and China on the issues regarding the South China sea. It also carefully looks at the possibility that, in the process of dealing with the issues, the two countries may get into an armed conflict as the phrase 'Thucydides Trap' predicts.

• Journal of the Korean Operations Research and Management Science Society
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• v.6 no.2
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• pp.7-11
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• 1981

An inspection-maintenance policy is investigated for a system having various states. A policy is characterized by the type of maintenance and the next inspection time. Maintenance actions are classified into various types according to the depth of maintenance. Policy evaluation criterion is the expected cost accumulated up to the failure of the system. The problem is formulated as a Markov decision process and an optimal policy is found by using a policy improvement procedure. A numerical example illustrates the policy for a system having five states.

• Journal of the military operations research society of Korea
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• v.4 no.1
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• pp.91-109
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• 1978

The paper discusses Cost and Operational Effectiveness Analysis (COEA) in the context of a military study system. The objectives of a study system, development of study programs, and management of studies are addressed. Basic cost-effectiveness models are presented and the COEA planning steps, analytical processes, and implementation discussed.

• Journal of the military operations research society of Korea
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• v.5 no.1
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• pp.19-25
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• 1979

• Nuclear Engineering and Technology
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• v.53 no.9
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• pp.2888-2898
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• 2021

Vital area identification (VAI) is an essential procedure for the design of physical protection systems (PPSs) for nuclear power plants (NPPs). The purpose of PPS design is to protect vital areas. VAI has been improved continuously to overcome the shortcomings of previous VAI generations. In first-generation VAI, a sabotage fault tree was developed directly without reusing probabilistic safety assessment (PSA) results or information. In second-generation VAI, VAI model was constructed from all PSA event trees and fault trees. While in third-generation VAI, it was developed from the simplified PSA event trees and fault trees. While VAIs have been performed for NPPs in full-power operations, VAI for NPPs in low-power and shutdown (LPSD) operations has not been studied and performed, even though NPPs in LPSD operations are very vulnerable to sabotage due to the very crowded nature of NPP maintenance. This study is the first to research and apply VAI to LPSD operation of NPP. Here, the third-generation VAI method for full-power operation of NPP was adapted to the VAI of LPSD operation. In this study, LPSD VAI for a few plant operational states (POSs) was performed. Furthermore, the operation strategy of vital areas for both full-power and LPSD operations was discussed. The LPSD VAI method discussed in this paper can be easily applied to all POSs. The method and insights in this study can be important for future LPSD VAI that reflects various LPSD operational states. Regulatory bodies and electric utilities can take advantage of this LPSD VAI method.

• Journal of National Security and Military Science
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• s.2
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• pp.121-163
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• 2004

Science technique development expanded into, not only land, sea, and air operations but also those of airspace, and cyber battle spaces. It is generally accepted at this time that space centric operations currently cannot be effectively divided from air operations. However, science and technology advancements make it possible to integrate Army, Navy, Airforce, and Marine forces into effective operations as never before. The Republic of Korea Armed Forces needs to establish a more effective joint concept. The US military, considered by many experts as the most effective in the world, understands the necessity of joint operations and accordingly has highly developed its own concept of joint operations. The US joint operational concepts demonstrated their effectiveness during the Iraqi War by dominating the battlefield through effective use of all combat and non-combat power. Following the US Iraqi War experience, the US Department of Defense continued to enhance Joint Capability through the acceleration of US Military Transformation involving all components. The future national security of the Republic of Korea, faced with the peculiarity of communist threat in the form of North Korea, and the conflicting interest of four strong powers; the United States, China, Japan, and Russia, depends on small but strong armed forces employing all available combat power through effective National and Military Strategy, and considering domestic and international constraints. In order to succeed in future wars, military operations following joint operational concepts must effectively employ all available combat power in a timely manner. The Republic of Korea Armed Forces must establish a joint forces concept in order to integrate all available combat power during employment. Therefore we must establish military operations that develop the military structure and organization, doctrine, weapon systems, training and education of our armed forces based on the key concept of joint operations.

• Strategy21
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• s.42
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• pp.53-82
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• 2017

Samuel Eliot Morison (1887-1976) was one of the pre-eminent historians of his generation. He was not only a famous historian at that time, but also was promoted to the rank of Admiral in U.S. Navy Reserve. Fifteen volume History of United States Naval Operations in World War II was published between 1947 and 1962, was not only a comprehensive report on the Navy's projection of power over two oceans, but a classic of historical literature that stands as the definitive treatment of it subject. Although he was fifty-five when war come to America in December 1941. Samuel Eliot Morison was determined to play a role. A professor at Harvard at the time, he joined volunteering for duty in the Navy. An experienced sailor, Professor Morison had earlier sailed that same routes taken by Christopher Columbus while researching his biography, Admiral of the Ocean Sea, which appeared in January 1942 th much acclaim and later got a Pulitzer Prize. Thus Morison plunged into the war, crossing the Atlantic aboard a destroyer. He assumed himself as "Parkman on the sea", tried to follow Parkman's historiographic method, not only participatory history but also literary style. And during writing History of United States Naval Operations in World War II, He emphasized two principles, publicity and objectivity. In terms of publicity, he always worried about who read history and why. In his pamphlet, "History as a Literary Art", he asserted it is useless if readers do not read a history which historians wrote. So he thought historians have forgotten that there is an art of writing of history. Therefore, he built his narratives around brightly rendered visuals and used the present tense to describe actions he witnessed firsthand, he wrote of the U.S. combat in very vividly. But strongly driven by publicity, he sometimes lost his balance in writing the naval history. For instance, the naval history became the focus of criticism for its prejudiced comments about the commanders. Also some reviewers asserted he did not secure the objectivity on writing the naval history. Although he sometimes deliberately torpedoed the objectivity of his work for strengthening publicity, by writing an extensive U.S. naval history, he introduced maritime history and naval history to the public widely. Until in early twentieth century, U.S. historians usually had been focusing their effort to the traditional areas, for example politic, economy, and etc. His intensive effort on the operations of U.S. Navy in World War II aroused a public interest in maritime and naval history. In conclusion, through using literary style and realistic narratives, historian Morison wrote a naval history for all the people which could appealed to the public.