In this study, the frequency response analysis of a bistable electromagnetic vibration energy harvester is performed, based on an electromagnetic oscillator model, to investigate its nonlinear dynamic behaviors. The displacement and current responses are obtained, by the direct integration of the model, with the variations of mechanical and electromagnetic parameters. It is shown that the operating frequency band of the system can be broadened by the increase in mechanical parameters(inertial mass and Q-factor), but it does not depend significantly on any electromagnetic parameters(an external load resistance and the internal resistance of a coil). On the other hand, the output current of the energy harvester is affected only by the electromagnetic parameters (specifically, the sum of two resistances). Thus, the mechanical and electromagnetic parameters of the electromagnetic energy harvester must be designed properly, respectively, for broader and more efficient performance.

본 연구는 고등학생의 건강증진행위를 설명하기 위한 가설적 모형을 구축하고 검증하기 위해 시도되었다. 연구대상자는 경기도 소재의 고등학교에 재학중인 1∼3학년 학생 395명을 대상으로 구조화된 설문지를 이용하여 2017년 12월01일부터 12월22일까지 자료를 수집하였다. 본 연구의 외생변수는 가족기 능, 친구지지, 학교생활환경, 지역사회 사회자본이고 내생변수는 자기효능감, 자기조절능력과 건강증진행위 이다. 수집된 자료는 SPSS 21.0과 AMOS 22.0 프로그램을 이용하여 분석하였다. 연구결과, 최종 수정모형 은 권장수준을 만족하여 가설적 모형에 비해 적합도와 간명도가 향상된 것으로 나타났다: χ2/df=1.96, GFI=.90, AGFI=.88, CFI=.94, TLI=.93, RMSEA=.05, SRMR=.06. 가설적 모형에서 설정한 13개의 경로 중 4개는 기각되었고 9개의 경로는 통계적으로 유의하였다. 이들 경로에 포함된 변수는 가족기능(β=.57), 자기효능감(β=.29), 자기조절능력(β=.14), 지역사회 사회자본(β=.14), 친구지지(β=.13)로 설명력은 86%이었다. 따라서 역기능적 가정과 해당 가정의 청소년의 건강증진행위를 위한 사회적지지 체계를 구축 하고 학교를 포함한 지역사회 환경조성을 위한 프로그램 개발이 필요하다.

PURPOSES : The purpose of this study is to analyze the crack and vertical behaviors of a continuously reinforced concrete pavement (CRCP) under three different steel ratios (0.6%, 0.7%, and 0.8%) using field measurement data acquired from isolated concrete slabs with transverse cracks. METHODS : Using an LVDT and a crack gauge, CRCP behavior data are acquired by segmenting a concrete slab into multiple sections based on the similarity in the longitudinal steel ratio of each section. To examine the vertical behavior of CRCP based on longitudinal steel ratios, three field experiments are conducted in February, May, and September three years after project completion. The minimum and maximum ambient temperature data for each section are acquired during the experiments. Using the data acquired, the vertical and crack behaviors of CRCP with 0.6% of longitudinal steel ratios are analyzed. In addition, the effect of the steel ratio on the vertical behavior as well as seasonal vertical behaviors are examined. RESULTS : Analysis of the vertical behavior of concrete slabs with a 0.6% steel ratio shows that the minimum vertical displacement occurred at the center of the slab, whereas a significant vertical displacement is detected on the edges of the slab. Based on examining vertical displacements formed along the direction of transverse cracks, it is observed that the vertical behavior is prominent around the shoulders, whereas similar vertical behaviors are observed at the center and joints of the slab. Furthermore, it is discovered that the minimum crack occurred at the center of the transverse cracks, whereas the maximum crack occurred on the shoulders and joints. Furthermore, it appears that the daily displacements of the vertical behavior at the center of the slab constitute approximately one-half of the daily displacements on the joints. Based on the results of vertical behavior as a function of the longitudinal steel ratios, it is discovered that steel ratios of 0.7% and 0.8% yield the most prominent vertical behaviors around the edge of the shoulder in the winter, spring, and fall seasons. The seasonal deviations of the vertical behaviors based on the measuring positions of the longitudinal steel ratios appear less significant at the center of the slab than those on the shoulder. In particular, for the slab with a steel ratio of 0.8%, subtle vertical behaviors are observed at the center. It is discovered that the seasonal deviation of the vertical behavior measurements varying by the measuring locations of the steel ratios appears less significant at the center of the slab than at the shoulder, and that it decreases with the steel ratio. CONCLUSIONS : CRCP generates cracks on the slab; however, they are managed by rebars in the CRCP. This study reveals that the major vertical and crack behaviors of CRCP occur around the shoulders than at the center of the CRCP slab. Therefore, new methods for managing cracks on the CRCP shoulder should be developed to improve the performance of CRCP. It is hoped that the results presented herein will be useful for the advanced analysis of CRCP behaviors.

본 연구는 대학생들이 코칭 참여 경험을 통해 어떻게 진로장벽 요인을 극복 하고 진로준비행동 확립을 통해 나만의 진로찾기에 이르는지 심층적으로 탐색 하는 것이다. 이를 위해 대학생으로서 코칭에 5회 연속 참여한 학생들을 대상으로 그들이 대학생활에서 코칭에 참여하게 된 동기가 무엇이며, 코칭 참여 경험 이 코칭에 참여한 대학생들의 진로장벽과 진로준비행동에 미치는 영향을 질적 연구의 방법론 중 근거이론의 접근방법으로 탐색하였다. 탐색 결과 대학생들은 대학생활과 진로로 인한 다양한 문제들과 스트레스를 해결하기 위해 코칭에 참여하였으며, 코치와 함께 코칭을 통해 다양한 방법으로 자기탐색 과정을 거치며 나는 어떤 사람인지, 나의 강점은 무엇인지 등을 인지 하는 경험을 한다. 또한 진로탐색 과정을 통해 대학생들의 나는 어떤 일에 흥미를 느끼는지, 나의 어떤 심리적․환경적 요인이 나만의 진로를 주춤하게 하는지 등을 경험한다. 마지막으로 대학생들이 진로를 준비하고 결정하기 위해 필요한 행동적 즉 실천적 요인인 진로준비행동을 확립하는 등 코칭을 통해 나만의 진로 찾기와 대학생활에도 긍정적인 영향을 미치고 있음을 알 수 있다.

Herein, a series of g-C3N4 modified Bi2MoO6 nanocomposites using Bi2MoO6 and melamine as original materials are fabricated via sintering process. For presynthesis of Bi2MoO6 an ultrasonic-assisted hydrothermal technique is researched. The structure and composition of the nanocomposites are characterized by Raman spectroscopy, X-ray diffraction (XRD), and high-resolution field emission scanning electron microscopy (SEM). The improved photoelectrochemical properties are studied by photocurrent density, EIS, and amperometric i-t curve analysis. It is found that the structure of Bi2MoO6 nanoparticles remains intact, with good dispersion status. The as-prepared g-C3N4/Bi2MoO6 nanocomposites (BMC 5-9) are selected and investigated by SEM analysis, which inhibits special morphology consisting of Bi2MoO6 nanoparticles and some g-C3N4 nanosheets. The introduction of small sized g-C3N4 nanosheets in sample BMC 9 is effective to improve the charge separation and transfer efficiency, resulting in enhancing of the photoelectric behavior of Bi2MoO6. The improved photoelectronic behavior of g-C3N4/Bi2MoO6 may be attributed to enhanced charge separation efficiency, photocurrent stability, and fast electron transport pathways for some energy applications.

This study aimed to investigate the association between interest in beauty care and dietary behaviors of 581 (analysis rate 96.0%) high school girls in Incheon using a survey done in May 2019. Based on the degree of interest in beauty care, subjects were classified as “Beauty care group (n=346)”, and "Non-beauty care group (n=235)”. The mean age of the subjects was 16.5 years old. The beauty care group had significantly lower BMI than the non-beauty care group (p<0.01). The beauty care group showed a significantly higher interest in weight control than the non-beauty care group (p<0.001). The most time-consuming preschool morning activity in the beauty care group was beauty care, while that of the non-beauty care group was eating breakfast (p<0.001). The beauty care group had significantly higher frequency of exercise than the non-beauty care group (p<0.05). The number of individuals who skipped breakfast was significantly higher in the beauty care group. In addition, the beauty care group had a significantly higher frequency of taking morning snack, convenience food (p<0.01), sweet snacks (p<0.05), and processed beverages (p<0.05) than the non-beauty care group. Our result findings provide important information on the priority groups for nutrition education based on beauty care interest.

Stainless steel, a type of steel used for high-temperature parts, may cause damage when exposed to high temperatures, requiring additional coatings. In particular, the Cr2O3 product layer is unstable at 1000oC and higher temperatures; therefore, it is necessary to improve the oxidation resistance. In this study, an aluminide (Fe2Al5 and FeAl3) coating layer was formed on the surface of STS 630 specimens through Al diffusion coatings from 500oC to 700oC for up to 25 h. Because the coating layers of Fe2Al5 and FeAl3 could not withstand temperatures above 1200oC, an Al2O3 coating layer is deposited on the surface through static oxidation treatment at 500oC for 10 h. To confirm the ablation resistance of the resulting coating layer, dynamic flame exposure tests were conducted at 1350oC for 5–15 min. Excellent oxidation resistance is observed in the coated base material beneath the aluminide layer. The conditions of the flame tests and coating are discussed in terms of microstructural variations.

This study embraces the viewpoint that intercultural sensitivity can be efficiently increased by accepting the communication behaviors(CB) of different groups which are closely related to the components of world views. This study is to examine the CB of North Korean refugees with South Korean people in terms of intercultural sensitivity. It surveyed six North Korean refugees who could share their broad experience of CB. The results show that the participants experienced harsh communication behaviors caused by the dichotomous views, and the stereotypes due to the political impact in denial and defense stages of ethnocentrism. Although the CB based on human empathy in minimization stage was experienced, this situation was made when they tried concealing their origin or putting down their self-esteem. Also, in this stage their revealing the North Korean way of CB inadvertently caused misunderstandings and conflicts. Finally, based on the research findings, this study suggests some ways to accept the CB of North Korean refugees in terms of increasing intercultural sensitivity.

본 연구는 중년기 성인의 치매태도와 예방행위에 대해 조사하고 이들 간의 관계를 파악하기 위한 서술적 조사연구이다. 연구대상자는 일개지역 G시에 거주하는 중년기 성인 146명이며, 구조화된 설문지를 이용하여 2019년 11월부터 12월까지 자료를 수집하였다. 자료분석 방법은 SPSS/WIN 24.0 프로그램을 이용하여 빈도와 백분율, t-test, ANOVA, Pearson's correlation coefficient로 분석하였다. 연구 결과 중년기 성인의 치매태도는 50점 만점에 35.08점, 예방행위는 36점 만점에 29.02점으로 나타났다. 치매태도는 직업에서 유의한 차이가 있었고(t=2.13 p<.05), 예방행위에서는 치매조기예방 관심(F=29.39, p<.001), 가족 중 치매환자(t=-2.62 p<.05), 에서 유의한 차이가 있었다. 치매태도와 예방행위는 유의한 양의 상관관계(r=.281, p<.001)로 나타났다. 따라서 중년기 성인의 치매에 대한 예방행위를 증진시키기 위해서는 치매에 대한 긍정적인 태도 및 치매예방에 대한 생활습관 관리의 중요성을 강조하는 교육 프로그램 개발이 필요하다.

In horse management, the alarm system with sensors in the foaling period enables the breeder can appropriately prepare the time of the parturition. It is important to prevent losses by unpredictable parturition because there are several high risks such as dystocia and the death of foals and mares during foaling. However, unlike analysis in the alarm system that detects specific motions has been widely performed, analysis of classification following specific behavior patterns or number needs to be more organized. Thus, the objective of this study is to classify signs of the specific behaviors of the mares for the prediction of pre-foaling behaviors. Five Thoroughbred mares (9-20 yrs) were randomly selected for observation of the prefoaling behaviors. The behaviors were monitored for 90 min that was divided into three different periods as 1) from -90 to -60 min, 2) from -60 to -30 min, 3) from -30 min to the time for the discharge of the amniotic fluid, respectively. The behaviors were divided into two different categories as state and frequent behaviors and each specific behavioral pattern for classification was individually described. In the state behaviors, the number of mares in the standing of the foaling group (3.17 ± 0.18b) at period 3 was significantly higher than the control group (1.67 ± 0.46a). In contrast, the number of the mares in the eating of the foaling group (1.17 ± 0.34b) at period 3 was significantly lower than the control group (3.33 ± 0.46a). In the frequent behaviors, the weaving of the foaling group was significantly higher than the control group, and looking at the belly of the foaling group was significantly lower than the control group. In period 2, defecation, weaving, and lowering the head of the foaling group were significantly higher than the control group, respectively. In period 3, sitting down and standing up, pawing, weaving, and lowering the head in the foaling group were also significantly higher than the control group. In conclusion, the behavior is significantly different in foaling periods, and the prediction of foaling may be feasible by the detection of the pre-foaling behaviors in the mares.

본 연구는 코로나19 유행 시기 간호대학생의 코로나19에 대한 불안, 위험인식, 정보이해력, 감염예방행위 이행 수준을 파악하기 위해 시도되었다. 본 연구는 서술적 조사연구로 2020년 6월 8일부터 6월 14일까지 간호대학생 224명을 대상으로 온라인을 통해 설문조사를 실시하였다. 수집된 자료는 SPSS 26.0을 이용하여 기술통계, t-test, ANOVA, 상관관계 분석을 하였다. 간호대학생의 불안정도는 6.86점(최대10점)으로 보통 수준이었으며, 위험인식은 8.19점(최대10점), 정보이해력은 3.50점(최대4점), 감염예방행위 수행정도는 4.44점(최대5점)으로 높은 수준이었다. 감염예방행위는 불안정도, 위험인식, 정보이해력이 높을수록 수행정도가 높았다. 코로나19와 같은 신종감염병이 유행할 때는 감염에 대한 불안감과 위험인식이 증가할 수 있으므로 감염병에 대한 충분한 정보제공으로 감염병에 대한 정확한 이해가 필요하다. 신종 감염병에 대한 정확한 이해는 철저한 감염예방행위를 향상 시키므로 감염병 전파 위험을 감소시킬 수 있을 것이다.

This study was conducted to investigate the effect of the power ranking of mares on their offspring’s stereotypies and response behaviors against a restraining of their desire to eat. Nine horses (2-4 years old) - three offspring born from three Haflinger mares over 3 years - were assigned to three experimental groups (High, Middle, Low) divided by the power ranking of mares. Three mares had no oral or locomotor stereotypic behaviors, but the higher the power ranking of mares, the more diverse and longer the duration of the oral stereotypies of their offspring (p<0.05). Although the offspring born from the high-ranking mare vigorously continued oral stereotypies until 3-4 years of age, there were no individuals that progressed to chronic locomotor stereotypies such as crib-biting, weaving, and box-walking. With an increase in the power ranking of the mare, the response of her offspring to the restraining of the eating desire (measured in terms of the frequency of the oral and locomotor stereotypies) increased (p<0.05). In conclusion, the oral stereotypies shown in this study are characteristic behaviors that occur during the growth process. However, in the case of riding horses, the offspring of a high-power ranking mare and/or one that reacted excessively against restrains, may be better observed and treated in a stall to manage stereotypic behaviors and correct the behaviors at their initial stage.

The behaviors of various desorption agents were investigated during the desorption of cesium (Cs) from samples of clay minerals and actual soil. Results showed that polymeric cation exchange agents (polyethyleneimine (PEI)) efficiently desorbed Cs from expandable montmorillonite, whereas acidic desorption solutions containing HCl or PEI removed considerable Cs from hydrobiotite. However, most desorption agents could desorb only 54% of Cs from illite because of Cs’s specific adsorption to selective adsorption sites. Cs desorption from an actual soil sample containing Cs-selective clay mineral illite (< 200 μm) and extracted from near South Korea’s Kori Nuclear Power Plant was also investigated. Considerable adsorbed 137Cs was expected to be located at Cs-selective sites when the 137Cs loading was much lower than the sample’s cation exchange capacity. At this low 137Cs loading, the total Cs amount desorbed by repeated washing varied by desorption agent in the order HCl > PEI > NH4+, and the highest Cs desorption amount achieved using HCl was 83%. Unlike other desorption agents with only cation exchange capabilities, HCl can attack minerals and induce dissolution of metallic elements. HCl’s ability to both alter minerals and induce H+/Cs+ ion exchange is expected to promote Cs desorption from actual soil samples.

지금까지 선행연구에서는 아동기에 대한 자서전적 기억이 한 개인의 자기개념에 영향을 끼침을 보고하였다. 반면, 아동기 경험의 회상방식이 성인기의 친사회적 행동에 어떻게 영향을 끼치는지에 대한 연구는 거의 수행되지 않았다. 이에 따라 본 연구에서는 아동기에 대한 자서전적 기억과 친사회적 행동의 관계를 해석수준에 따라 분석하려 한다. 연구 1에서는 대학생들을 대상으로 아동기 또는 최근 일상의 경험을 회상하는 조건에서 다양한 친사회적 행동에 대한 동기화가 달라지는지를 비교하였다. 연구 2에서는 아동기 경험을 추상적 또는 구체적으로 회상하는 방식이 해석수준의 차이를 통해 친사회적 행동에 영향을 끼치는지를 검증하였다. 그 결과 연구 1에서는 아동기의 경험을 회상 하는 조건에서 친사회적 행동의 동기화정도가 높게 나타났다. 또한 연구참가자들은 아동기의 경험을 회상하는 조건에서 최근 일상을 회상하는 조건보다 자신의 도덕적 순수함에 대해 더 높게 평정하였다. 연구 2에서는 아동기의 도움행동을 구체적으로 회상하는 조건에서 아동기의 경험을 추상적으로 회상하는 조건보다 향후 친사회적 행동의 동기화가 감소됨을 보여주었다. 이 결과는 아동기의 경험에 대한 해석수준(추상적 vs. 구체적)과 도덕적 면허의 감정이 친사회적 행동의 동기화에 영향을 끼칠 가능성을 보여준다. 본 연구는 한 개인의 친사회적 행동과 연관된 인지과정 의 변인을 탐색하여 선행연구를 확장했다는데 의의가 있다.