• Title/Summary/Keyword: 근접장 강화

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Numerical Analysis of Electromagnetic and Temperature Fields Induced by Femtosecond Laser Irradiation of Silver Nanowires (은 나노선 펨토초 레이저 조사에 의해 유도되는 전자기장 및 온도장 수치 해석)

  • Ha, Jeonghong;Kim, Dongsik
    • Laser Solutions
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    • v.18 no.1
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    • pp.12-17
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    • 2015
  • This work performed numerical analysis of electromagnetic field and thermal phenomena occurring in femtosecond laser irradiation of silver nanowires. The local electric field enhancement was computed to calculate the optical energy dissipation as a Joule heating source and the thermal transport was analysed based on the two-temperature model (TTM). Electron temperature increased up to 1000K after 50fs and its spatial distribution became homogeneous after 80fs at the fluence of 100mJ/cm2. The result of this work is expected to contribute to revealing the photothermal effects on silver nanowires induced by femtosecond laser irradiation. Although the highest increase of lattice temperature was substantially below the melting point of silver, the experimental results showed resolidification and fragmentation of the silver nanowire into nanoparticles, which cannot be explained by the photothermal mechanism. Further studies are thus needed to clarify the physical mechanisms.

Effect of Direct Solar Radiation with Sloped Topography in a Mesoscale Meteorological Model (중규모 기상모형에서 지표면 경사를 고려한 직달 복사량의 효과)

  • Shin, Sun-Hee;Lee, Young-Sun;Ha, Kyung-Ja
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.4
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    • pp.45-59
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    • 2006
  • In this study, the effects of the surface topographical characteristics on the meteorological fields are examined in a mesoscale meteorlolgical model. We calculated the direct solar radiation using the illumination angle considering the inclination of topography and tried to find out its effect on meteorological fields. In above experiments, we selected two cases for the clear day and the cloudy day to show the effect of weather and represented the results for two cases. In the correction of the direct solar radiation, the results of two cases indicate that there are obvious differences on the steep Taeback and Soback mountains. And on the time-series analysis the east-facing slope of these mountains receives the more direct solar radiation about $10-60W/m^2$ in the morning hours but lesser in the afternoon hours than the horizontal surface while it is opposite on the west-facing slope. And the results mentioned above are more obvious at clear day. With the same analysis method, at clear day, the surface skin temperature is higher at all hours than that on horizontal surface on the both of slope. At cloudy and rainy day, the surface skin temperature on the east-facing slope is higher in the morning hours but lower in the afternoon hours than that on horizontal surface. But on the west-facing slope, it is higher at all hours than that on horizontal surface. In the two cases, the temperature considering the slope of surface is almost higher than that on the horizontal surface. The wind is stronger than that on the horizontal surface with increasing pressure gradient force according as increasing temperature gradient around the Taeback and the Soback mountains.

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Earnings Management and Cost Stickiness: Evidence from Mongolia (몽골기업의 이익조정과 원가의 하방경직성)

  • Ser-Od, Bolortuya;Koo, Jeong-Ho
    • Journal of Industrial Convergence
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    • v.20 no.9
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    • pp.25-38
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    • 2022
  • The purpose of this paper is to verify the cost behavior of non-listed companies in Mongolia from 2013 to 2018. And we investigate the relationship between cost behavior and earnings management. Earnings management was measured using the Big-Bath and avoiding loss incentives. Big-Bath suspected firms report a very large loss and avoiding loss suspected firms have a bite profit. The results of this study are as follows. First, non-listed firms in Mongolia, operating costs(oc) and selling, general and administrative(sga) costs show the cost stickiness. Second, cost stickiness was different depending on the earnings management. The suspected avoiding loss firms have upward earnings management incentives, operating costs and sga costs all present anti-cost stickiness. The suspected big bath firms strengthen the cost stickiness of operating costs and sga costs. This study is meaningful in that it first analyzed the relationship between earnings management and cost stickiness of non-listed firms in Mongolia using empirical data. It will be meaningful in that it provides relevant information to those interested in research and investment.

A Study Security Measures for Protection of VIP in the G20 Summit (G20 정상회의 시 주(主)행사장에서의 VIP 안전대책 방안에 관한 연구)

  • Lee, Sun-Ki;Lee, Choong-Soo
    • Korean Security Journal
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    • no.24
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    • pp.91-123
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    • 2010
  • The threat factors available for occurrence given G20 Summit Meeting are expected leader terrorism, hostage terrorism, bomb terrorism, public facilities terrorism, and aircraft terrorism. As for the threat groups, which are expected in Korea, the North Korea, Islam extremist group, and the group such as NGO organization of being opposed to international meeting are regarded as having possibility of causing hazard. Thus, the purpose of this study is to suggest VIP Security-measure plans in the main site in preparation for G20 Summit Meeting. Accordingly, each country in the world is adopting 'the principle of Triple Ring' in common. Thus, it elicited a coping plan by 1st line(inner ring) 2nd line(middle ring) 3rd line(outer ring) based on this principle, and proposed even an opinion together that will need to be reflected in light of policy for the VIP security measures. In conclusion, as for the VIP Security-measure plans in the main site in preparation for G20 Summit Meeting, In the inner ring(safety sector), first, an intercepting measure needs to be devised for a spot of getting into and out of vehicles given the Straight Street. Second, the Walking Formation needs to be reinforced boldly in the exposed area. In the middle ring(security sector), first, the control plan needs to be devised by considering particularity of the main site. Second, there is necessity for adopting the efficient security badge operation plan that is included RFID function within security badge. In the outer ring(aid protective sector), first, there is necessity of preparing for several VIP terrorisms, of collecting information and intelligence, and of reinforcing the information collection system against terrorism under the cooperation with the overseas information agency. Second, the urgent measure training in time of emergency needs to be carried out toward security agent event manpower. Third, to maintain the certain pace in VIP motorcade, the efficient traffic control system needs to be operated. Finally, as for what will need to be reflected in light of policy for VIP security measures, first, there is necessity for allowing VIP residence to be efficiently dispersed to be distributed and controlled. Second, there is necessity for allowing impure element to misjudge or attack to be failed by utilizing diverse deception operations. Third, according to the reorganization in North Korea's Organization of the South Directed Operations, the powerful 'military-support measure' needs to be driven from this G20 Summit Meeting. For this, the necessity was proposed for further reinforcing the front back defense posture under the supervision of the Ministry of National Defense and for positively coping even with detecting and removing poison in preparation for CBR (chemical, biological, and radio-logical) terrorism.

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Analysis of Utilization and Maintenance of Major Agricultural machinery (Tractor, Combine Harvester and Rice Transplanter) (핵심 농기계(트랙터, 콤바인 및 이앙기) 이용 및 수리실태 분석)

  • Hong, Sungha;Choi, Kyu-hong
    • Journal of the Korean Society of International Agriculture
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    • v.30 no.4
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    • pp.292-299
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    • 2018
  • In a survey in which farmers were asked about their levels of satisfaction with agricultural machines, Japanese products scored higher than local products by 1.2, 1.3, and 1.4 times for tractors, combine harvesters, and rice transplanter, respectively. Japanese products corresponded to generally high satisfaction levels in terms of operating performance, operability, frequency of breakdowns, and durability, excluding sales price and after-sales services. Effective countermeasures through quality improvement are therefore necessary for Korean products. Furthermore, a survey of dealers showed that the components and consumables for core agricultural machines had high frequencies of breakdowns and repairs. Four major components of tractors represented 85.3% of all breakdowns and repairs, five components of combine harvesters represented 89.6%, and three components of rice transplanters represented 80.5%. Moreover, a comparison of the technological levels between local and imported machines showed that the local machines' levels were at 60-100% for tractors, 70-100% for combine harvesters, and 70-95% for rice transplanters. Small and mid-sized tractors, 4 interrow combine harvesters, and 6 interrow rice transplanters showed similar levels of technology. The results of the analysis suggest that action is urgently needed at a policy level to establish an agricultural machinery component research center for the development, production, and supply of commonly-used components, with the participation of manufacturers of agricultural machines and components, in order to enhance the competitiveness of local manufacturers and to revitalize the agricultural machine market.

The study about role of enforcement stage in safety activity for the international conference (국제회의 안전활동에 있어서 실시단계의 역할에 관한 연구)

  • Lee, Sun-Ki
    • Korean Security Journal
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    • no.36
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    • pp.387-416
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    • 2013
  • This study's purpose is to present the improvement of effectiveness of security activity for international conference which can be held hereafter. On the basis of security activity problems originating in G20 summit meeding that had been held in Seoul in 2010. I made up questions three times to on the members of the police, military, fire figher and national intelligence service who had experienced in Seoul G20 summit meeding and recognition of possible problem and possibility of improvement on each item of questions was analyzed by Delphi Method. Also interviews with 4 security experts selected from each security agency were conducted to present improvement in each part of problem. The results obtained from the face to face interview with four experts of security-enforcement agency about the role of event site activity stage for international conference are as followings; First, 'security protocol section' protocol and security are needed mutual win-win enough to be compared with adaptative relationship, thereby being demanded the closer cooperation and information exchange. Second, 'situation management section' there is a need of reinforcing the cooperative system between situation rooms of each agency in order to possibly operate all of the security manpower integrally, which are dispersed by function and by event site, in addition to the swift and organic information exchange between wide-area local government and all the security agencies focusing on a preparation planning group. Third, 'security manpower resource management section' there is a need of encouragement and interest in the leadership in order to devise system that all of the security manpower can concentrate on event and to be possibly satisfied the given conditions. Fourth, 'local government cooperative support section' the wide-area local government of a hosting city as international city operates several kinds of the facilities for international conference, supports operation of conference, achieves a ripple effect of event such as tourism, maximizes service of accomodations, and performs the primary responsibility for the maintenance of the traffic facilities, thereby needing to execute special inspection under the responsibility of Si-Do governors.

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