• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.2
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• pp.246-254
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• 2018

Psychological stress and physical fatigue, such as anxiety, fear, sleep disturbance, etc., caused by exposure to the war, can lead to post-traumatic stress syndrome(PTSD) or war syndrome. The military has also prepared for drug use to minimize war syndrome and preserve combat strength. However, efforts to prevent war syndrome are still lacking. This study was conducted to identify biomarkers that can track psychophysiological changes. Psychophysiological changes associated with PTSD can be divided into four main categories. The four categories are behavioral changes, changes in brain cognition, neuroimmunological changes, and changes in innate immunity. This study suggest that biomarker profile can be made by the distance moved and the anxiety-like behavior in the open field for behavior category, brain BDNF levels in the brain cognition category, serum corticosterone in the neuroimmunology category, and inflammatory cytokine levels in the innate immunity category.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.4
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• pp.407-416
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• 2020

Recent complex battle field demands Network Centric Warfare(NCW) ability to control various parts into a cohesive unit. In path planning filed, the NCW ability increases complexity of path planning algorithm, and it has to consider a communication coverage map as well as traditional parameters such as minimum radar exposure and survivability. In this paper, pros and cons of various propagation models are summarized, and we suggest a coverage map generation method using a Longley-Rice propagation model. Previous coverage map based on line of sight has significant discontinuities that limits selection of path planning algorithms such as Dijkstra and fast marching only. If there is method to remove discontinuities in the coverage map, optimization based path planning algorithms such as trajectory optimization and Particle Swarm Optimization(PSO) can also be used. In this paper, the Longley-Rice propagation model is used to calculate continuous RF strengths, and convert the strength data using smoothed leaky BER for the coverage map. In addition, we also suggest other types of rough coverage map generation using a lookup table method with simple inputs such as terrain type and antenna heights only. The implemented communication coverage map can be used various path planning algorithms, especially in the optimization based algorithms.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.4
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• pp.656-663
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• 2018

As the virtual reality technology, which has been attracting attention recently in the era of the fourth industrial revolution, is spreading and spreading throughout the society, expectation about virtual reality is gradually increasing. The major big companies such as Samsung and LG in Korea are concentrating on R &D and early ecosystem composition of virtual reality field as well as large global corporations such as Google and Facebook. But in Korea, the environment is not well equipped to compete with the global market and although there are many SMEs and start-up companies related to virtual reality, there are few successful companies. In this study, we analyze the domestic and foreign virtual reality market and industry and present ways of activation on virtual reality industry. We analysis by PEST analysis, SWAT and competitive structure analysis.Based on the analyzed results, ways to revitalize the virtual reality industry are suggested in this paper.

• Journal of the Korean institute of surface engineering
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• v.43 no.3
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• pp.132-141
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• 2010

NiTi alloy has been used for orthodontic wire due to good mechanical properties, such as elastic strength and frictional resistance, combined with a high resistance to corrosion. Recently, these wire were coated by polymer and ceramic materials for aesthetics. The purpose of this study was to investigate surface characteristics of polymer coated NiTi alloy wire for orthodontics using various instruments. Wires (round type and rectangular type) were used, respectively, for experiment. Polymer coating was carried out for wire. Specimen was investigated with field emission scanning electron microscopy(FE-SEM), energy dispersive x-ray spectroscopy(EDS) and atomic force microscopy(AFM). The phase transformation of non-coated NiTi wire from martensite to austenite occurred at the range of $14{\sim}15^{\circ}C$, in the case of coated wire, it occurred at the range of $16{\sim}18^{\circ}C$. Polymer coating on NiTi wire surface decreased the surface defects such as scratch which was formed at severe machined surface. From the AFM results, the average surface roughness of non-coated and coated NiTi wire was 13.1 nm, and 224.5 nm, respectively. From convetional surface roughness test, the average surface roughness of non-coated and coated NiTi wire was $0.046{\mu}m$, and $0.718{\mu}m$, respectively.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.6
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• pp.9-15
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• 2018

According to the development and use of self-consolidating concrete in field, interest in material properties of early-age concrete is rising. Setting time with hydration process of cement is one of significant indicator to evaluate the early-age material properties of concrete, various nondestructive methods including penetration resistance measurement have been proposed to estimate setting time. This study performed an experimental approach to evaluate setting time delay in mortar adding superplasticizer using electrical resistivity measurement. For this purpose, total nine types of mortar samples were prepared, and its electrical resistivity was monitoring during 24h after mixing. From the experimental result, rising time of electrical resistivity was used to evaluate setting delay of mortar, and penetration resistance was also measured for comparison. In addition, dynamic elastic modulus and compressive strength of 1day mortar were measured to investigate a possibility the use of electrical resistivity measurement for evaluation of early-age material properties.

• Journal of the Korean association of regional geographers
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• v.10 no.3
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• pp.554-567
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• 2004

Since the 1980s, the academic interests on the regional geography have been renewed. This trend is usually called 'Renaissance' of the regional geography. Given this context, to explore diverse theories and methodologies in the regional geography is of much significance. Particularly, to examine the regional geography in Germany widens the understanding of not only the history, strength, and weakness of the regional geography, but also the discipline's status in the field of geography. This paper discusses the regional geography in Germany before World War II, focusing on varieties of theories and methods as well as the historical trajectory of the German regional geography. This discussion may well be significant in that 'Laenderkunde' became an important paradigm in the discipline of geography in Germany during the pre-World War II period.

• Journal of the Korean Society for information Management
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• v.27 no.4
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• pp.239-258
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• 2010

The purpose of this study is to develop a prediction model of patent citation counts based on major factors which affect patent citation. To this end, we performed multiple regression analysis between the patent citation counts and five explanatory variables such as the number of pages, the number of claims, the reference-average-citation rate, the strength of bibliographic coupling, and the document similarity proved as having 5% or more standardized variances($r^2$) with patent citation counts, with a test dataset of U.S. patents in five subject fields. As a result, our prediction models showed 58.3% to 89.6% predictability depending on subject fields and revealed the document similarity has the highest impact on citation counts among the five predictive variables in all the subject fields. The result of comparison between the predicted citation counts and the actual ones confirmed the usefulness of the citation prediction models built for each subject field.

• Journal of Astronomy and Space Sciences
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• v.19 no.4
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• pp.377-384
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• 2002

We have developed Real-time Phase DAta processor(RPDAP) for GPS L1 carrie. And also, we tested the RPDAP's positioning accuracy compared with results of real time kinematic(RTK) positioning. While quality of the conventional L1 RTK positioning highly depend on receiving condition, the RPDAP can gives more stable positioning result because of different set of common GPS satellites, which searched by elevation mask angle and signal strength. In this paper, we demonstrated characteristics of the RPDAP compared with the L1 RTK technique. And we discussed several improvement ways to apply the RPDAP to precise real-time positioning using low-cost GPS receiver. With correcting the discussed weak points in new future, the RPDAP will be used in the field of precise real-time application, such as precise car navigation and precise personal location services.

• Journal of the Korean institute of surface engineering
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• v.49 no.3
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• pp.260-264
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• 2016

In this study, fractured surface morphology and mechanical properties of Ni-Cr-Mo alloys with various contents of Mo for dental material use have been evaluated by mechanical test. The alloys used were Ni-13Cr-xMo alloys with Mo contents of 4, 6, 8, and 10 wt.%, prepared by using a vacuum arc-melting furnace. Ni-13Cr-xMo alloys were used for mechanical test without heat treatment. The phase and microstructure of alloys using an X-ray diffraction (XRD) and optical microscopy (OM) were evaluated. To examine the mechanical properties of alloys according to microstructure changes, the tensile test and the hardness test were carried out using tensile tester. To understand the mechanism of Mo addition to Ni-Cr alloy on mechanical property, the morphology and fractured surfaces of alloys were investigated by field-emission scanning electron microscope (FE-SEM). As a result, 79Ni-13Cr-8Mo alloy was verified that the tensile strength and the hardness were better than others. Varying Mo content, the changes of microstructures of alloys were identified by OM and SEM and that of 79Ni-13Cr-8Mo alloy was proved fabricated well. Microstructures of alloys were changed depending on Mo content ratio. It has been observed that 8% alloy had the most suitable mechanical property for dental alloy.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.813-816
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• 2006

Today us the creation of knowledge and find, accumulation and use ability is living in the knowledge base society where the base of social advancement becomes. The social members as sleep and the production where is not the consumer of knowledge, own lead whole life studying as they sleep and, they are soft and an open accident, must equip the hazard which gets information and the knowledge which are new the whole life must endeavor. From the hazard which is adapted to like this social change the education for a technical find was necessary absolutely, the education against an updated technology became essential element from the If field which changes soddenly specially. From the dissertation which it sees if in the object facing each other from IT curriculum analyzes the merit and demerit of method and the WBI and against the hereafter developmental subject for an efficient education to sleep it researches the IT industry worker and it does.