• Journal of the Korean Society of Visualization
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• v.17 no.2
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• pp.39-47
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• 2019

Impingement cooling utilizing synthetic jets is emerging as a popular cooling technique because of its high local cooling efficiency. The interaction between the vortex structure of the synthetic jet and the surface is crucial in understanding the mechanism of this technique. In this study, the impinging vortex structure and its advection are investigated by experiments with jet-to-surface spacing $2{\leq}H/D{\leq}7$, and synthetic jet Reynolds number $5120{\leq}Re{\leq}9050$. Using phase-locked particle image velocimetry, ensemble averaged (phase averaged) flow fields are obtained, and vortex identification and quantification techniques are applied. The shape, trajectory, and intensity change of the vortex are assessed. A sharp decline in the vortex intensity and the occurrence of a counter-rotating vortex at the impingement point are observed.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.6
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• pp.574-579
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• 1999

A counter-flow type horizontal reactor of metal organic chemical vapor deposition was designed with the Reynolds and the Rayleigh numbers of Re = 4.5 and Ra = 215.8, respectively. The GaN thin films were grown and characterized by Hall measurement, double crystal X-ray diffraction analysis and photoluminescence measurement. The Si and Mg were also used for doping of GaN films. The dislocation density of $2.6{\times}10^8/\textrm {cm}^2$ was included in GaN films representing the geometrical lattice mismatch between sapphire substrates and GaN films. The Si doped n-GaN films provide the electron carrier density and mobility in the regions of $10^{17}~10^{18}/\textrm{cm}^3$ and 200~400 $\textrm{cm}^2$/V .sec, respectively. Mg doped p-GaN films were post-annealed and activated with the hole carrier density of $8{\times}10^{17}/{\textrm}{cm}^3$.

• Strategy21
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• s.39
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• pp.163-197
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• 2016

The completion of Jeju Naval Base on February 2016 made the Republic of Korea Navy(ROKN) review the size and role of the Maritime Task Flotilla(MTF). The new strategic environment for the 12st century and the new challenges require the Navy to counter North Korea's provocations and prevent potential enemy's threat. The Navy is also required to take part in the variety of international roles and missions commensurated with Korea's global status to maximize the national interest. Despite these changes, Korea's military construction concept is still unable to break away from the old paradigm of the North Korean threat largely centered. In order to develop the current MTF into the Task Group with the construction of Jeju Naval Base, the Navy must newly not only establish new force development plan and fleet management concepts but also go to persuade and convince policy decision makers. To this end, the following efforts should be promoted. First, the ROK Navy steps up efforts in order to share with the Task Group's vision and strategy. The Navy should also provide the size and structure as well as the missions and roles of the Task Group to react to new maritime security environment. Second, the Navy analyse the MTF's ability and what is required and necessary to perform its duty. After that, it must set out the direction of the Task Group's force development. Third, the current missions and roles of the MTF should be re-established to respond various threats. Finally, accommodating of new technology to the MTF should intensify its strengths. The ROK Navy has a mixed force structure consisting of three fixed- base fleets and a MTF. The fixed base fleet has a passive force to defend and protect its own sea areas, but the MTF should actively not only counter North Korea's threats, including ballistic missiles, but also fight potential threats and takes international missions as a primary task force. However, the MTF has a limited capability to accomplish given missions and long-range operations, and thus, the ROK Navy is strongly required to construct the Task Group.

• Journal of the Society of Disaster Information
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• v.5 no.2
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• pp.50-73
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• 2009

This paper is about the establishment of "Initial Response System." Initial response system is most important and should be treated urgently among all preparations for chemical terrorism. The objects of Initial response system are to protect civilians and the first responder who are exposed directly to chemical terrorism. Therefore, this paper suggests two main issues about Initial response system. One is to prepare immediate and exact information service system which assures the safety and survival of exposed people. The other is to build Scene Response System integrated with Command-Control Procedure for early finished situation. Compared to United States, overcoming the Chemical Terrorism requires to improve the contents of two categories: Counter Citizen Response part and Initial Scene Response part. For Counter citizen response part' s sake, the web-sites of Response leader agencies for searching information about chemical terrorism should be modified specifically. These web-sites have to be re-organized in detail. The existing Information service system which has been vaguely informed as "CBRNE Accident" needs to be divided as "CBRNE Accident" and "WMD terrorism." Further, each of them should be specialized in "Chemical', "Biological", and "Radiological" categories. There is a need to rearrange current Emergency Instruction for civilians against chemical terrorism in feasible way. At the same time, it should be applied consistently to all organizations through agreement between experts and related-organizations. For Initial Scene Response part's sake, "Initial scene response procedure (SOP)" and "Operational conception" should be produced through Simulated Exercises and workshops of all organizations related with initial response. These organizations have to cooperate with Ministry of Environment which is the main leader Agency as the center. Next, there is a need to develop a technology and Scene Response Equipments, and to standardize the response equipments which consider the capability of First Responders for chemical terrorism. Especially, improving capability of equipments is required to overcome the vulnerability of Scene Response Equipments.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.12
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• pp.1821-1830
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• 2001

The flow around free end of a finite circular cylinder (FC) embedded in an atmospheric boundary layer has been investigated experimentally. The experiments were carried out in a closed-return type subsonic wind tunnel with varying aspect ratio of the finite cylinder mounted vertically on a flat plate. The wakes behind a 2-D cylinder and a finite cylinder located in a uniform flow were measured for comparison. Reynolds number based on the cylinder diameter was about Re=20,000. A hot-wire anemometer was employed to measure the wake velocity and the mean pressure distributions on the cylinder surface were also measured. The flow past the FC free end shows a complicated three-dimensional wake structure and flow phenomenon is quite different from that of 2-D cylinder. The three-dimensional flow structure was attributed to the downwashing counter rotating vortices separated from the FC free end. As the FC aspect ratio decreases, the vortex shedding frequency decreases and the vortex formation length increases compared to that of 2-D cylinder. Due to the descending counter-rotating twin-vortex, near the FC free end, regular vortex shedding from the cylinder is suppressed and the vortex formation region is hardly distinguished. Around the center of the wake, the mean velocity for the FC located in atmospheric boundary layer has large velocity deficit compared to that of uniform flow.

• The Journal of the Korea Contents Association
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• v.12 no.2
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• pp.116-126
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• 2012

As a film maker, Lee Chang Dong stands out from most Korean film makers who work within the trappings of genre films. To be sure, Lee has also used the trappings of genre films, such as noire and melodrama, but primarily as a tool to communicate with film audience. In his most recent film "Poetry", Lee seems to have even stripped even the minimal trappings of genre film. Lee commands the audience to self-reflect and work towards their own conclusions by denying them the illusory identification on screen. In this way, Lee's works are counter cinema. Lee achieves a distancing effect using such filmic apparatuses as hand-held camera, fantasy, mise en abyme, and returned gaze. Through these filmic apparatuses, Lee exposes the re-presentation of text and compels his audience to see the historical and political contexts of the text. In this study, I make the case that Lee Chang Dong's film making is an act of repetition compulsion that cultivates ethical reflection, through symbolization of the invisible realities.

• The Korean Journal of Air & Space Law and Policy
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• v.21 no.2
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• pp.123-155
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• 2006

2001. 9. 11 aviation terror showed us that there are lots of problems in aviation security and we need efficient counter-plans. According to this event, many countries are coming up with various countermeasures. After first hijacking in 1950, the aviation terror is occurring with more various methods until these days. And the scale is bigger than former so they're making much bigger damages. Especially, the case of 9.11 terror attracted people's eye of the world because of enormous casualties and damages. It aroused many people's self-awakening therefore as an important factor the security is given much weight in the aviation safety. In order to keep the step like this tendency and the development of aviation security, beginning with America lots of countries of the world are pursuing diverse aviation security's counter-plans of new side. At this point of time, for our development in aviation industry we should make efficient aviation security countermeasures. In this study, We compared our aviation security activities with major countries after 9.11 terror.

• Korean Journal of Adult Nursing
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• v.18 no.3
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• pp.345-356
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• 2006

Purpose: This study was conducted to compare the process of change, decisional balance, and self-efficacy according to the stages of change of exercise on the basis of the Transtheoretical Model in order to investigate factors associated with the change of exercise in adult diabetic patients. Method: Data were collected from January to April 2005. The subjects were 160 patients in the G university hospital and public health center in J city. Results: The entire process of change showed the significant difference depending on the stage of change(F=20.007, p=.000). For each process of change, the Consciousness Raising(F=14.602, p=.000), Dramatic Relief(F=7.751, p=.000), Environmental Re-evaluation(F=11.843, p=.000), Self Re-evaluation(F=16.035, p=.000), Social Liberation(F=10.968, p=.000), Counter-conditioning (F=24.090, p=.000), Helping Relationships(F= 7.625, p=.000), Reinforcement Management(F= 16.693, p=.000), Self Liberation(F=11.990, p= .000) and Stimulus Control(F=4.020, p=.002) demonstrated significant differences depending on the stages of change of exercise. For the decisional balance, the Pros showed the significant difference depending on the stage of change(F=14.121, p=.000). For the self efficacy showed significant difference depending on the stage of change(F=17.137, p=.000). Conclusion: In order to proceed the stage of change of exercise in patients with Diabetes Mellitus, intensive use of a specific process of change, a stage of change matching is needed.

• Korean Journal of Veterinary Service
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• v.45 no.1
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• pp.39-45
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• 2022

The total bacteria count is significantly important factor for hygienic quality in raw milk. BactoScan FM^TM and BactoCount IBC^TM are the automated instruments for the determination of the total bacterial count in raw milk. They have been used after calibration by standard plate count (SPC) method in South Korea since 2000. It is necessary to re-evaluate for total bacterial counter according to the improvement of milk quality and the change of milk quality grade. Therefore, this study was evaluated the conversion mode of the two machines by SPC method. We collected 921 bulk-tank milk samples throughout the concentration range of 1,000~1,000,000 CFU/mL from June 2020 to October 2021. As a result, when compared by the SPC value, there was a slight difference in total bacterial count in BactoScan below 10,000 CFU/mL and above 200,000 CFU/mL and in BactoCount above 100,000 CFU/mL, respectively. Therefore, the conversion factor for BactoScan and the conversion equation for BactoCount were newly adjusted based on SPC value, and then the correlation coefficients (R²) was 0.85 or higher. In addition, the correlation (R²) between BactoScan and BactoCount was 0.91, which means the results were high positive correlation. These results are expected to contribute to improving the accuracy of the automated instruments for determining of total bacterial count in raw milk.

• Herbal Formula Science
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• v.15 no.1
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• pp.117-128
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• 2007

We re-classified traditional medicinal prescriptions in Dong-Eui-Bo-Gam for the modern application using Tradimed database. They could be devided into 6 categories by the definitions of the related laws. Herbal ethical drugs are the majority, 3926 items, account for 60.21% of total items. Herbal Health Functional Foods stands second, 1480 items, 22.70%, Herbal over the counter drugs are 893 items, 13.69%. These three categories are about 83% of total items. Herbal medical supplies are 158 items, 2.42%, Herbal medical tools are 44 items, 0.67%, Herbal cosmetics are 20 items, occupied 0.31 %. Therefore we have known that traditional medicinal prescriptions can be used not only as drugs, but also as funtional foods, cosmetics, and tools. So they should be developed as modern products to make best use of them. And we suggested that we need official criteria of herbs of careful use and higher standards for herbs which can be used as foods.