• Journal of the military operations research society of Korea
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• v.17 no.2
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• pp.1-15
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• 1991

If one were to say that war is political in its nature, then war could be one of the several ways of achieving political goals. Thus, the aspect of wars will, in certainty, be altered by the changes in political environment. Wars in the past broke out mainly due to ideological differences that ran to extremes and were of high intensity. However, wars today show such restraints as controlling them beforehand or during the war in anticipation of the post-war situation. The trend of ideas to actualize such wars in the effective operation of airpower is on the rise. Airpower normally possesses speed and operative flexibility as well as capability of destruction, so it is possible to destroy the politically declared targets clearly. Previous airpower was merely employed as means of helping to vertically detouring the spatial obstacle that the ground forces encountered. Over the years, due to the speedy improvement of aviation technology and of ideas concerning wars in space, more advanced application has been developed. but they also were nothing more than an auxiliary role to facilotate the ground forces, that needed a longer effective range of firepower and did not become forces with the right of self-determination, that is, the fact of decisive war that makes its outcome. However, under transitional strategic environment like that of the present, Airpower possesses not only the capability to operate as a decisive means of war but also as theories to support it. The advancement in air technology has enabled supremacy over targets in depth, and the development of electronic technology has empowered the improvement of degree of destruction but also triumphant war by means of an overwhelming supremacy in a relatively short period. Thus, the method of systematic destruction that accomplishes the stated goals while rejecting the damage of accumulative destruction has been realized. The progress of such a concept has also proved that the counter-force strategy that has been developed in nuclear strategy is useful in conventional warfare as well. Therefore, it can be said that the under today's strategic environment airpower is an outstanding means of military strategy that can deeply affect to achieve the national objectives.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.3
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• pp.265-273
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• 2006

In the decommissioning and decontamination(D&D) planning stage, it is important that the scenarios are evaluated from an engineering point of views because the decommissioning work has to be executed economically and safely by following the best scenarios. Therefore, we need to develope several modules to evaluate the decommissioning scenarios. In this paper, the digital mock-up system is constructed in the virtual space to simulate the whole decommissioning process. The schedule evaluating equation and cost evaluation equation are derived to calculate the working time and the expected cost. And in order to easily identify the radiation level about the activated objects, the radiation visualization module is developed. Finally, on the basis of the obtained results from the Digital Mock-up and other important factors, the evaluating method of the scenarios that can indicate the best scenario is described.

• Tunnel and Underground Space
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• v.21 no.2
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• pp.117-127
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• 2011

The purpose of this study is to demonstrate the effect of in-situ rock stresses on the deformability and permeability of fractured rocks. Geological data were taken from the site investigation at Forsmark, Sweden, conducted by Swedish Nuclear Fuel and Waste Man-agement Company (SKB). A set of numerical experiments was conducted to determine the equivalent mechanical properties (essentially, elastic moduli and Poisson's ratio) and permeability, using a Discrete Fracture Network-Discrete Element Method (DFN-DEM) approach. The results show that both mechanical properties and permeability are highly dependent on stress because of the hyperbolic nature of the stiffness of fractures, different closure behavior of fractures, and change of fluid pathways caused by deformation. This study shows that proper characterization and consideration of in-situ stress are important not only for boundary conditions of a selected site but also for the understanding of the mechanical and hydraulic behavior of fractured rocks.

• Proceedings of the Korea Information Assurance Society Conference
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• 2004.05a
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• pp.219-225
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• 2004

There is increasing tension in the Korean Peninsula from the US' putting the NK's nuclear issue along the line of war in Iraq. However, there is worsening in ROK's field exercise condition from decresing defense financial supports, being difficlut to obtain enough space for volumable exercises, and securities and circumstances issues. With acknowleging those problems, CPX(Command Post Exercise), namely war game exercise which is more economical and scientific exercise has earned its attention as the best alternative measure of field exercise war game exercise has already been applyied to independent, joint, and combined exercises. However, the current war game system contains lots of problems in terms of security. Defense network uses dedicated line isolated with internet and secure data through network level encoding. It is vulerable to get attack during war game exercise or from credited network. System security is also subject to reinforced. This research is performed focusing on network and system level securities, and through it, the author will show the effective and optimized security solution for war game system.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.2
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• pp.103-112
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• 1990

This study examines the characteristics of soil behavior which includes many uncertainties in seismic design, evaluates the dynamic soil properties and studies the soil-structure interaction to generalize the applicability and economy of the available sites. An example analysis is performed for soil-structure system response assuming a containment structure built on site which includes soil layers using both elastic halfspace analysis and FEM analysis against the seismic loads from the actual design. This exercise is performed as a part of the safety analysis and economic assessment of the nuclear power plant built on soils. It includes the preparation of computer program capable of incorporating large nonlinearity in the analysis, resonable evaluation procedures to determine input soil data. Nonlinear FEM analysis of Seed and Idriss model is found suitable for the accurate analysis of dynamic response of soils. Linear FEM analysis using dynamic soil properties at strain level obtained by one-dimensional seismic response, and elastic half-space analysis using dynamic soil properties at strain level under static loads are recommended to evaluate the dynamic soil properties.

• The Korean Journal of Cytopathology
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• v.10 no.1
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• pp.61-66
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• 1999

Angiosarcomas are rare tumors, seen most commonly in the skin and soft tissue of head and neck legion. But it has been described in numerous body sites including thyroid, breast, liver, spleen, bone, etc.. Their biological behaviors depend on the microscopic grade, site of origin, and multifocality. We report the unique cytological features of an angiosarcoma in pleural fluid. A 61-year-old woman presented with a 6 month history of dyspnea on exertion and chest pain. Chest computerized tomography(CT) revealed multiple subpleural small nodules in the right lung and widespread all space consolidation and pleural effusion in the left lung. CT of liver revealed multiple small low attenuated lesion. The smears obtained from pleural fluid showed hypocellularity with a hemorrhagic background. The tumor cells were highly pleomorphic oval or spindle in shape and presented singly, in loose groups, in knitted syncytial aggregates, and in acinar pattern. Their nuclei had vesicular chromatin with delineated, thick nuclear membranes and occasionally a large eosinophilic, prominent nucleolus. The cytoplasm was plump, thin or protected in spindly fashion. Almost ail tumor cells showed variable sized intracytoplasmic vacuoles and their nuclei were sometimes crescentic by a huge vacuole. Occasional binucleated tumor cells and mitotic figures were present. Cellular debris and streaky materials were identified. Needle biopsy specimen from the pleura revealed anastomosing slit-like spaces lined by pleomorphic tumor cells. The tumor cells showed a strong reactivity for CD31 and vimentin and focal weak reactivity for factor VIII-related antigen.

• Tunnel and Underground Space
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• v.11 no.2
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• pp.132-145
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• 2001

The purpose and need of the study is to quantify the advantage or disadvantage of the environmental friendliness of the partitioning of nuclear fuel cycle. To this end, a preliminary study on the quantitative effect of the partition on the permanent disposal of spent PWR and CANDU fuel (HLW) was carried out. Before any analysis, the so-called reference radionuclide release scenario from a potential repository embedded into a crystalline rock was developed. Firstly, the feature, event and processes (FEPs) which lead to the release of nuclides from waste disposed of in a repository and the transport to and through the biosphere were identified. Based on the selected FEPs, the ‘Well Scenario’which might be the worst case scenario was set up. For the given scenario, annual individual doses to a local resident exposed to radioactive hazard were estimated and compared to that from direct disposal. Even though partitioning and transmutation could be an ideal solution to reduce the inventory which eventually decreases the release time as well as the peaks in the annual dose and also minimize the repository area through the proper handling of nuclides, it should overcome major disadvantages such as echnical issues on the partitioning and transmutation system, cost, and public acceptance, and environment friendly issues. In this regard, some relevant issues are also discussed to show the direction for further studies.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.4
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• pp.539-545
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• 2012

To evaluate of the ultrasonographic changes in hemiplegic and unaffected knee joints of hemiplegic ambulators with recent onset stroke. Twenty patients (40 knees) with prevalence duration of 14-39 weeks (mean 24.70 weeks) after a stroke insult were included. All participants were walking independently without leg dragging, had no previous knee injury. There were significant differences in intercondylar cartilage thickness and pes anserinous tendinopathy (PAT) between hemiplegic and unaffected knees (p<0.05). There were no differences in cartilage thickness of medial condyle and lateral condyle, patellar tendinitis/bursitis, suprapatellar effusion, synovitis, joint space narrowing, and Baker's cyst of ultrasonographic findings and x-ray findings in hemiplegic knee compared to the control except PAT (p<0.05). In hemiplegic knee, medial or lateral condylar cartilage thickness was significantly correlated with body weight, intercondylar cartilage thickness, and PAT (p<0.05). PAT was significantly correlated with Brunnnstrom stage and condylar cartilage thickness (p<0.05). Knee pain was significantly correlated with lateral condylar cartilage thickness (p<0.1). The hemiplegic knee had more ultrasonographic abnormalities including PAT and more cartilage thickness preservation in patient with recent onset stroke. Intraarticular sonographic findings including cartilage thickness was significantly correlated with extraarticular findings including PAT and a symptom of knee pain.

• Journal of Advanced Navigation Technology
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• v.21 no.5
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• pp.491-500
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• 2017

This paper investigates a low cost dual modular redundancy system based on heartbeat which can be applied to traffic control signal system. Failure of the traffic control signal system can cause traffic confusion and traffic accidents. Therefore safety and reliability of traffic control should be secured using fault tolerance technology. To do this, we configured a redundant board using the open source hardware and the heartbeat technique of Linux HA. The function of the traffic signal control system was verified and the fault recovery time was measured using fault injection test. As a result of the test, the fault recovery time was confirmed to be less than 9 seconds on average, confirming that the reliability target time is satisfied. Based on the results of this study, it is expected that it can be applied to fields requiring high reliability systems such as aviation, space, and nuclear power embedded systems.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.1
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• pp.9-14
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• 2013

In recent years, high hardness steel is used for most of the material in many areas including aircraft, nuclear power, space exploration and automotive parts. Low CBN tools are widely used in industrial field which can effectively process high hardness steel of HRC 45 or harder. The results of this study demonstrated, when high hardness steel, SCM440 is turned with Low CBN tools coated with TiN and TiAlN coatings respectively, that both the thrust force and cutting force tends to increase with more increase in cutting force than thrust force, as the feed rate increases at constant cutting speed. In addition, the size of the cutting force and thrust force does not change with the increased cutting speed at the same feed rate, but the tool life is reduced if the cutting speed is increased to shorten the machining time. Therefore, it is recommended to limit the cutting speed at 250 m/min maximum or less. Furthermore, comparing the cutting force of the three tools at the same cutting condition, Tin coating tool showed the smallest cutting force and Low CBN was the next, and the TiAlN coating tools showed the largest cutting force.