The purpose of this study is to analyze research trends in Korean language education for North Korean refugees. In pursuance of this goal, the study collected bibliographic information from 1,924 academic papers related to North Korean defectors and analyzed their research trends using language network analysis methods. The frequency and centrality of the academic papers were analyzed by year, using an analysis tool, NetMiner 4.0, which focuses on analyzing social networks. The findings of the analysis were as follows: First, the study of North Korean defectors began to explode in 2010. Second, the most central words were ‘education,’ ‘unification,’ ‘policy,’ ‘support,’ ‘experience’ and ‘relationship.’ Third, for North Korean defectors, Korean language education as a foreign language was more actively done than general Korean language education. Fourth, the analysis of 15 topics showed that topics on social issues accounted for the highest percentage at 25%. Finally, the areas of greatest interest in Korean language education were vocabulary, pronunciation, and intonation education. It is hoped that more research on Korean language education for North Korean defectors will be carried out in the future.

The research model of panel data analysis in this study was used as the dependent variables and the business characteristics of the welding industry were reflected in the research model for systematic analysis of the effect of welding technology on the welding industry. As a result of the existing research, the domestic welding technology is seriously encroaching on the domestic welding industry between the United States, Japan and China. There is no quantitative statistical analysis on this aspect. In this study, the panel data analysis is used to indicate differences in explanatory power by numerical values of POLS model, fixed effect and random effect. And the prior studies on the current status of welding industry related to arc welding, special welding, multiple welding, welding and bonding technology are applied by the panel data analysis. Therefore, the problems of existing research are diagnosed while presenting the future research directions.

u-Health는 개인용 생체정보 측정 장치나 유무선 통신망 인프라를 사용하여 장소와 시간에 제약 없이 질병의 예방, 상태파악, 치료, 예후, 건강 및 생활 관리의 개인 맞춤형 보건의료서비스를 제공하는 기술이다. 본 연구는 K 보건소의 u-Health 기반의 대사증후군 관리를 위한 u-Healthcare 서비스에 대한 사례연구로 이용자들이 서비스에 어떠한 가치를 부여하고 있는지, 이용자와 제공자간 소통은 적합한지, 아울러 서비스에 대한 이용자의 개인적 관심에 대하여 서비스 제공자는 공감을 형성하고 있는지 등의 인본주의적 관점에서의 접근이다. 대상자의 건강정보이해능력, 서비스의 질, 서비스에 대한 가치부여, 서비스 제공자와의 의사 소통 및 공감형성, 서비스 만족도, 재이용의도를 살펴보았으며, 자료는 편의추출로 수집하였다. 건강정보이 해능력은 재이용의도와만 유의미한 상관관계를 보였으며, 그 외의 변수들은 서로 유의미한 상관관계를 보였다. 본 연구를 통해 보건소의 지역사회 기반 대사증후군 관리 u-Healthcare 서비스가 소득이 적은 대상자들에게 공공보건의료서비스로서 가치가 높다는 것과 의사소통 및 공감형성이 다른 변수들과 높은 상관관계를 나타내며 중요한 역할을 하고 있다는 것을 확인하였다. 따라서 u-Healthcare 서비스의 성공적 인 정착을 위해서는 이용자의 개인적 관심에 공감하고 맞춤형 서비스를 제공할 수 있도록 이용자와 의료진 간의 충분한 의사소통과 피드백이 반드시 필요하고 이를 위해 인적, 시스템적 지원이 지속적으로 필요하다.

In this study, the flat glass and adsorption pad were modeled using SolidWorks Simulation, to understand the deformation characteristics of the vertical flat glass by the adsorption pressure during vertical transport of LCD. The horizontal and vertical displacements and equivalent stresses of the flat glass were investigated by the structural analysis. From the displacement and stress visualization according to the adsorption pressure, the higher the adsorption pressure, the larger the glass surface protruded. The horizontal deformation of flat glass increased with increasing thickness and the vertical deformation increased with decreasing thickness. In addition, the maximum equivalent stress applied to the flat glass increased significantly as the adsorption pressure increased and the thickness decreased. As a result of the structural analysis, the thinner the thickness of the plate glass, the greater the effect on the adsorption pressure. Especially, the effect of the adsorption pressure was clearly observed at the thickness of 0.5mm.

This study examined how teaching and learning activities in primary English textbooks include the components of creativity and character building. Three third and fourth grade level textbooks based on the 2015 revised curriculum were analyzed in order to find the proportions of the components of creativity and character building, and the types of learning activities that embody those components were analyzed by examining the teachers’ guides. The analysis revealed that all of the textbooks examined included diverse components that were intented to increase creativity, among which components stimulating divergent thinking and originality were a high proportion, while convergent thinking and dispositional aspects appeared less frequently. Among character building components, care-forgiveness and responsibility were two of the more popular components, while honesty and moral judgment were few and far between. From these findings, this study suggests that the components of creativity and character building should be more evenly distributed across textbook activities since they should be of equal importance in education.

본 연구의 목적은 원자로 1400(APR 1400) 원자력 발전소(NPP)의 원자로 격납건물(RCB) 내진성능에 대해 상이한 수치모델과 지진 주파수 성분의 영향을 평가하는 것이다. 집중 질량 막대 모델(lumped-mass stick model, LMSM)과 3차원 유한요소모델(threedimensional finite element model, 3D FEM)의 두 가지 수치 모델이 시간이력해석을 수행하기 위해 개발되었다. LMSM은 기존의 집중 질량 보-요소를 사용하여 SAP2000으로 구성하였으며, 3D FEM은 각기둥 입체-요소를 사용하여 ANSYS로 작성되었다. 저주파수 및 고주파수 성분을 고려한 두 그룹의 지진파를 시간이력해석에 적용하였다. 저주파수 지진파의 응답스펙트럼을 NRC 1.60의 설계 스펙트럼과 일치되도록 조정하여 작성하였으며, 고주파수 지진파는 10Hz ~ 100Hz의 고주파수 범위를 갖도록 생성하였다. RCB의 지진응 답은 다양한 높이에서 층응답스펙트럼으로 검토하였다. 수치해석 결과, 저주파수 지진에 의한 구조물의 FRS 결과는 두 수치 모델에 서 매우 유사한 결과를 보였다. 하지만, 고주파수 지진에 의한 LMSM의 FRS 결과는 고차 고유 주파수 영역에서 3D FEM과 큰 차이를 보였으며, RCB의 낮은 높이에서 명확한 차이를 보였다. 3D FEM이 정확한 구조물의 응답을 나타내는 것으로 가정한다면, RCB의 LMSM은 고주파수 지진에 의한 FRS 결과의 고차 고유 주파수 영역에서 일정 수준의 불일치성을 내포하고 있다.

The change of fishing power index was analyzed to identify the development of the vessel and gear technology that may improve the fishing efficiency of the offshore conger eel pot fishery from 1980s to 2015. Gross tonnage per fishing vessel was rapidly increased annually. The standard of pot was maintained, but the number of pot used rapidly increased by using conger eel pot hauling devices, carrying and loading devices, main line hauler, casting devices and slide type pot. Fish finder system to identify fishing ground information and the conger eel pot hauling devices were modernized, and supply rate was also increased. Therefore, the relative fishing power index in the offshore conger eel pot fishery increased from 1.0 in 1980 to 1.3 in 1990, to 1.8 in 2000 and to 2.0 in 2015. The results are expected to contribute to reasonable fisheries stock management of the offshore conger eel pot fishery.

Thousands of pelagic and demersal fishes inhabit the waters around Korea and many of them are overexploited. One of the reasons is technological development, which increases the efficiency of the vessels continuously. The analysis was conducted to identify the change of fishing power index to develop the vessel and gear technology that may have improved the fishing efficiency of the otter trawl fishery from 1960s to 2010s. Gross tonnage was decreased stably, but horse power was increased annually. The perimeter of net mouth was somewhat longer, but little changed. Color fish finder was utilized from the mid-1960s. Hydraulic net drum were introduced in the early 1990s, and supply rate was gradually increased. Surveys on the supply and upgrading of fishing equipment utilized visiting research. Therefore, the relative fishing power index in the trawl fishery increased about two to three times in the 2010s compared to the 1980s. The results are expected to contribute to reasonable fisheries stock management.

Generally, vibration absorber systems are composed of spring-mass systems to reduce the vibration of a structure, and there are also methods to simply increase damping to achieve a damping effect across a wide frequency band. One similar method is to use a mechanism in which the eddy current is converted into a mechanical damping effect. When an eddy current is generated by electromotive force due to magnetic flux change, the reaction force is generated by the eddy current’s circulation. In this study, the damping system using the reaction force was constructed to reduce the transmission of vibrations generating from internal fluid and the vibration reduction characteristics that are transmitted externally were analyzed. As a result, 8.2 % of the vibration reduction effect from primary excitation frequency was confirmed.

Recent discoveries of ferroelectric properties in ultrathin doped hafnium oxide (HfO2) have led to the expectation that HfO2 could overcome the shortcomings of perovskite materials and be applied to electron devices such as Fe-Random access memory (RAM), ferroelectric tunnel junction (FTJ) and negative capacitance field effect transistor (NC-FET) device. As research on hafnium oxide ferroelectrics accelerates, several models to analyze the polarization switching characteristics of hafnium oxide ferroelectrics have been proposed from the domain or energy point of view. However, there is still a lack of in-depth consideration of models that can fully express the polarization switching properties of ferroelectrics. In this paper, a Zr-doped HfO2 thin film based metal-ferroelectric-metal (MFM) capacitor was implemented and the polarization switching dynamics, along with the ferroelectric characteristics, of the device were analyzed. In addition, a study was conducted to propose an applicable model of HfO2-based MFM capacitors by applying various ferroelectric switching characteristics models.

MoO3 metal oxide nanostructure was formed by hydrothermal synthesis, and a perovskite solar cell with an MoO3 hole transfer layer was fabricated and evaluated. The characteristics of the MoO3 thin film were analyzed according to the change of hydrothermal synthesis temperature in the range of 100 ℃ to 200 ℃ and mass ratio of AMT : nitric acid of 1 : 3 ~ 15 wt%. The influence on the photoelectric conversion efficiency of the solar cell was evaluated. Nanorod-shaped MoO3 thin films were formed in the temperature range of 150 ℃ to 200 ℃, and the chemical bonding and crystal structure of the thin films were analyzed. As the amount of nitric acid added increased, the thickness of the thin film decreased. As the thickness of the hole transfer layer decreased, the photoelectric conversion efficiency of the perovskite solar cell improved. The maximum photoelectric conversion efficiency of the perovskite solar cell having an MoO3 thin film was 4.69 % when the conditions of hydrothermal synthesis were 150 ℃ and mass ratio of AMT : nitric acid of 1 : 12 wt%.

PURPOSES: Nitrogen oxide (NOx) is a particulate matter precursor, which is a harmful gas contributing to air pollution and causes acid rain. The approaching methods for NOx removal from the air are the focus of numerous researchers worldwide. Titanium dioxide (TiO2) and activated carbon are particularly useful materials for NOx removal. The mechanism of NOx elimination by using TiO2 requires sunlight for a photocatalytic reaction, while activated carbon absorbs the NOx particle into the pore itself after contact with the atmosphere. The mixing method of these two materials with concrete, coating, and penetration methods on the surface is an alternative method for NOx removal. However, this mixing method is not as efficient as the coating and penetration methods because the TiO2 and the activated carbon inside the concrete cannot come in contact with sunlight and air, respectively. Hence, the coating and penetration methods may be effective solutions for directly exposing these materials to the environment. However, the coating method requires surface pretreatment, such as milling, prior to securing contact, and this may not satisfy economic considerations. Therefore, this study aims to apply TiO2 and activated carbon on the concrete surface by using the penetration method. METHODS : Surface penetrants, namely silane siloxane and silicate, were used in this study. Photocatalyst TiO2 and adsorbent activated carbons were selected. TiO2 was formed by the crystal structures of anatase and rutile, while the activated carbons were plant- and coal-type materials. Each penetrant was mixed with each particulate matter reductant. The mixtures were sprayed on the concrete surface using concentration ratios of 8:2 and 9:1. A scanning electron microscopy with energy dispersive X-ray equipment was employed to measure the penetration depth of each specimen. The optimum concentration ratio was selected based on the penetration depth. RESULTS: TiO2 and activated carbon were penetrated within 1 mm from the concrete surface. This TiO2 distribution was acceptable because TiO2 and activated carbon locate to where they can directly come in contact with sunlight and air pollutant, respectively. Infiltration to the concrete surface was easily achieved because the concrete voids were bigger than the nanosized TiO2 and microsized activated carbon. The amount of penetration for each particulate matter reductant was measured from the concrete surface to a certain depth. CONCLUSIONS : The mass ratio on the surface can be predicted from the mass ratio of the particulate matter reductant measurement distributed through the penetration depth. The optimum mass ratio was also presented. Moreover, the mixtures of TiO2 with silane siloxane and activated carbon with silicate were recommended with an 8:2 concentration ratio.

Background: A backpack is available equipment for moving some objects. Most studies have found that the appropriate weight limit of backpack for students is between 10% to 15% of their body weight (BW). However, Some students should carry a backpack heavier than 15% of BW. Therefore, It is associated with abnormal shoulder and neck posture on students. Objects: This study tested the effects that various amounts of weight carried by university students in their backpacks had on their cervical posture and electromyography of neck muscle. Methods: The subjects consisted of 12 students (6 male, 6 female) in university. There were three loading conditions tested: no backpack, a backpack that weighed 10% and 15% of the student’s BW. The dependent variables were the craniovertebral angle (tragus to C7) and the neck muscle activities (sternocleidomastoid, upper trapezius). All 12 subjects were asked to walk while wearing a backpack for 5 minutes and were then instructed to rest for 2 minutes. Results: When assessing the craniovertebral angle, the results of this study were significantly decreased in the order of 0%, 10%, and 15%. And then, there were significantly increased electromyography of neck muscles that comparison of the weight of 10% and 15% on 0%. It was found that as the weight of the backpack increased, the craniovertebral angle decreased (p < 0.05) and the muscle activities increased (upper trapezius p = 0.012, sternocleidomastoid p = 0.013). Conclusion: Our study recommended that some students shouldn’t carry on over the 15% backpack of own weight, and also they should distribute backpack load to equal on body for optimal posture.

The Fe-22wt.%Cr-6wt.%Al foams were fabricated via the powder alloying process in this study. The structural characteristics, microstructure, and mechanical properties of Fe-Cr-Al foams with different average pore sizes were investigated. Result of the structural analysis shows that the average pore sizes were measured as 474 μm (450 foam) and 1220 μm (1200 foam). Regardless of the pore size, Fe-Cr-Al foams had a Weaire-Phelan bubble structure, and α-ferrite was the major constituent phase. Tensile and compressive tests were conducted with an initial strain rate of 10−3 /s. Tensile yield strengths were 3.4 MPa (450 foam) and 1.4 MPa (1200 foam). Note that the total elongation of 1200 foam was higher than that of 450 foam. Furthermore, their compressive yield strengths were 2.5 MPa (450 foam) and 1.1 MPa (1200 foam), respectively. Different compressive deformation behaviors according to the pore sizes of the Fe-Cr-Al foams were characterized: strain hardening for the 450 foam and constant flow stress after a slight stress drop for the 1200 foam. The effect of structural characteristics on the mechanical properties was also discussed.

본 연구는 직경분포에 근거한 잣나무 임분수확표(지위지수 14)를 활용하여 등급별 목재 생산량을 분석하기 위해 수행되었다. 잣나무 임분수확표는 국립산림과학원에서 개발된 직경분포 함수를 이용하여 직경급별 본수를 예측하였으며, 목재 생산량은 말구직경 을 기준으로 3개 등급으로 구분하였다. 연구결과 잣나무 임분수확표를 활용한 원목생산량은 임령이 증가할수록 1등급 생산량이 증가하였고, 1등급(재장 3.6m) 원목은 40년부터 생산 가능한 것으로 분석되었다. 임분단위 원목의 생산량은 직경급별 생산되는 등급별 원목 개수와 직경급별 본수에 따라 생산량에서 차이를 보였다. 임령에 따른 등급별 원목의 이용재적은 원목 생산량에 비례하였 고, 2등급 이용재적비율은 30년과 40년일 때 전체 임분 이용재적의 60% 이상을 차지하였으며, 임령이 증가할수록 1등급 이용재적비율 이 높아짐에 따라 감소하였다. 임분단위 이용재적은 임령이 증가할수록 1등급과 2등급(재장 3.6m) 이용재적은 증가하였고 3등급은 감소하였다. 임분단위 이용재적비율은 3등급의 경우 20년일 때 85% 이상 차지하였고, 2등급은 40년일 때 74% 이상 차지하였으며, 1등급 이용재적이 증가하는 50년 이후 부터 감소하였다.

개느삼은 한반도의 일부 지역에 제한적으로 분포하는 특산식물이며, IUCN Red List의 ‘Endangered’로 지정된 희귀식물 이다. 본 연구는 자생지의 환경변화로 쇠퇴 위협이 있는 개느삼의 분포 패턴과 개체군 구조를 조사 분석하여 향후 개느삼 개체군의 동태 및 지속성 파악을 위한 기초 자료 활용에 목적이 있다. 개느삼 개체군의 특성을 파악하기 위해 양구, 춘천, 홍천 3개 지역에 각각 2~3개의 대방형구(20m×30m)를 능선을 기준으로 설정하고, 대방형구 안에 4~7개 Transect상의 소방형구(1m×1m)를 2m 간격으로 각각 10개씩 총 530개를 설정하여 출현 개체 수 및 결실 개체 수, 개체 높이 등을 측정하였 다. 확보된 종발생정보를 IUCN Red List ver 3.1의 평가기준 B를 적용하여 기존 IUCN에 평가된 범주와 비교분석하였다. 조사된 세 개 지역의 평균 개체 밀도는 3.47본/㎡로 나타났으며, 지역별로 양구 3.95본/㎡, 춘천 3.37본/㎡, 홍천 2.87본/㎡ 이었다. 한편, 개체군의 결실률(결실 수/개체 수)은 0.0038으로 전체 출현 개체 1,837본 중에 7본만이 결실된 것으로 나타나 생식생장(sexual reproductive) 보다는 영양생장(vegetative reproduction) 비율이 매우 높을 것으로 추정된다. 조사된 세 지역의 소방형구 개체 밀도의 분포 경향을 분석한 결과, 개느삼은 수관 열림이 높은 산지 능선을 중심으로 수관 열림이 낮은 숲 중심부로 갈수록 개체 밀도가 감소하는 경향을 보여줌으로써, 광량이 개느삼 개체의 생육에 매우 중요한 요소일 것으로 추정된다. 한편, 방형구내 출현하는 전체 개체의 높이를 분석한 결과 2.3~68.5cm로 나타났으며, 평균 20.1cm로 조사되었다. 개체 높이를 바탕으로 개느삼 개체군의 stage-structure를 분석한 결과 15~20cm를 기점으로 개체 높이가 높아질 수록 점차 출현빈도가 감소하는 경향을 보여주었으며, seedling으로 추정되는 10cm 이하의 개체들의 비율도 매우 낮게 나타남으로써 향후 모니터링 자료를 바탕으로 개체군의 지속성에 대한 분석이 필요할 것으로 보인다. 한편, 확보한 종발생정보 를 바탕으로 산출된 점유면적은 200㎢로 나타나 IUCN Red List 기준(criteria) B 적용 시 EN 범주를 충족하는 것으로 나타났다.

Fusarim oxysporum에 의한 덩굴쪼김병은 수박 재배에 큰 피해를 일으키는 중요한 병이다. 이 병을 방제하기 위해 덩굴 쪼김병 저항성 박 대목을 이용하는 것이 가장 좋은 방법이다. 본 연구는 박 덩굴쪼김병 저항성 자원을 선발할 수 있는 방법을 확립하기 위해 수행하였다. 효과적인 접종법을 개발하기 위해 접종 후 온도(15, 20, 25, 30°C), 접종 농도(1 X 105, 5 X 105, 1 X 106 and 5 X 106 conidia･mL-1), 접종 시기(파종 7, 10, 13, 16일 후)를 조사하였다. 박 덩굴쪼김병을 접종하였을 때 접종 후 배양 온도나 파종 후 접종 시기의 영향이 적었다. 그러나, 덩굴쪼김병에 저항성인 박의 경우 접종농도가 높을수록 발병이 심하게 나타났다. 따라서, 박 덩굴쪼김병에 대한 효과적인 접종법으로 파종 10일 된 유묘 뿌리를 1 X 105 - 1 X 106 conidia･mL-1 농도로 30분간 접종한 후 감염되지 않은 토양에 옮겨 심고 25°C에서 3주 동안 재배하는 것을 제안한다.

Carbon supports for dispersed platinum (Pt) electrocatalysts in direct methanol fuel cells (DMFCs) are being continuously developed to improve electrochemical performance and catalyst stability. However, carbon supports still require solutions to reduce costs and improve catalyst efficiency. In this study, we prepare well-dispersed Pt electrocatalysts by introducing titanium dioxide (TiO2) into biomass based nitrogen-doped carbon supports. In order to obtain optimized electrochemical performance, different amounts of TiO2 component are controlled by three types (Pt/TNC-2 wt%, Pt/TNC-4 wt%, and Pt/TNC-6 wt%). Especially, the anodic current density of Pt/TNC-4 wt% is 707.0 mA g−1 pt, which is about 1.65 times higher than that of commercial Pt/C (429.1 mA g−1 pt); Pt/TNC-4wt% also exhibits excellent catalytic stability, with a retention rate of 91 %. This novel support provides electrochemical performance improvement including several advantages of improved anodic current density and catalyst stability due to the well-dispersed Pt nanoparticles on the support by the introduction of TiO2 component and nitrogen doping in carbon. Therefore, Pt/TNC-4 wt% may be electrocatalyst a promising catalyst as an anode for high-performance DMFCs.

In this study, the uniformity of the horizontal velocity and the temperature of each zone were investigated by computerized analysis method to divide the drying room into three multi - rooms to ensure the uniformity of flow inside the forced convection hot air dryer. The internal structure of the drying room of the dryer was modeled using Solidworks. In order to control the flow of hot air circulating in the drying chamber, the possibility of controlling the horizontal flow inside the drying room was verified by using a perforated plate, a guide vane, and a vertical plate. From the results of the flow visualization in the drying room, it was understood that the internal flows of the dryer models 1, 2 and 3 change from ununiform flow to uniform flow. From the analysis of velocity and temperature fluctuation, the results of the analysis of the dryer model 3 satisfied the design conditions.