• Title/Summary/Keyword: Hall Effect

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A Comparison of Alcohol Secondhand Effects among Korean and U.S. College Students (한국과 미국 대학생의 간접음주피해 비교)

  • Chun, Sung-Soo;Sohn, Ae-Ree;Reid, Easton A.;Inot, Rubelyn;Kim, Mi-Kyung;Percoheles, Grace;Lee, Sang-Sook;Wechsler, Henry
    • Korean Journal of Health Education and Promotion
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    • v.26 no.5
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    • pp.115-127
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    • 2009
  • Objectives: To compare alcohol secondhand effects among US and Korean students. Methods: Nationally representative 4-year colleges of two countries were involved in this cross-national comparison study. Data from the 2001 U.S. College Alcohol Study and the 2003 Korean College Alcohol Study came from 120 colleges in 38 U.S. states and the District of Columbia and 60 colleges in Korea. Randomly selected 4-year college students from the U.S. (10,924) and Korea (2,385) participated in the study using self-reports of alcohol use and perceptions of drinking as assessed by College Alcohol Study questionnaires. Results: Korean students were tend to more likely to have being a victim of sexual assault or date rape, having to take care of drunken students and finding vomit in the hall or bathroom of residence, than US students, while US students were tend to more likely to have being insulted or humiliated, having a serious argument and quarrel, being pushed, hit, or assaulted, having study/sleep interrupted, and experiencing an unwanted sexual advance than Korean students. Conclusion: In general, US students were more likely to suffer interrelationship problems after drinking while Korean students were more likely to have physical and individual drinking related problems.

Growth and Optical Conductivity Properties for BaAl2Se4 Single Crystal Thin Film by Hot Wall Epitaxy (Hot Wall Epitaxy(HWE)법에 의한 BaAl2Se4 단결정 박막 성장과 광전도 특성)

  • Jeong, Junwoo;Lee, Kijung;Hong, Kwangjoon
    • Journal of Sensor Science and Technology
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    • v.24 no.6
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    • pp.404-411
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    • 2015
  • A stoichiometric mixture of evaporating materials for $BaAl_2Se_4$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $BaAl_2Se_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperatures were $610^{\circ}C$ and $410^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of $BaAl_2Se_4$ single crystal thin films measured from Hall effect by van der Pauw method are $8.29{\times}10^{-16}cm^{-3}$ and $278cm^2/vs$ at 293 K, respectively. The temperature dependence of the energy band gap of the $BaAl_2Se_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=3.4205eV-(4.3112{\times}10^{-4}eV/K)T^2/(T+232 K)$. The crystal field and the spin-orbit splitting energies for the valence band of the $BaAl_2Se_4$ have been estimated to be 249.4 meV and 263.4 meV, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_5$ states of the valence band of the $BaAl_2Se_4/GaAs$ epilayer. The three photocurrent peaks observed at 10 K are ascribed to the $A_1$-, $B_1$-exciton for n =1 and $C_{31}$-exciton peaks for n=31.

Parametric Study on Wing Design of Insect-mimicking Aerial Vehicle with Biplane Configuration (겹 날개를 사용하는 곤충 모방 비행체의 날개 형상에 대한 파라메트릭 연구)

  • Park, Heetae;Kim, Dongmin;Mo, Hyemin;Kim, Lamsu;Lee, Byoungju;Kim, Inrae;Kim, Seungkeun;Ryi, Jaeha;Choi, Jong-Soo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.9
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    • pp.712-722
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    • 2018
  • This paper conducts parametric studies on flapping wing design, one of the most important design parameters of insect-mimicking aerial vehicles. Experimental study on wing shape was done through comparison and analysis of thrust, pitching moment, power consumption, and thrust-to-power ratio. A two-axis balance and hall sensor measure force and moment, and flapping frequency, respectively. Wing configuration is biplane configuration which can develop clap and fling effect. A reference wing shape is a simplified dragonfly's wing and studies on aspect ratio and wing area were implemented. As a result, thrust, pitching moment, and power consumption tend to increase as aspect ratio and area increase. Also, it is found that the flapping mechanism was not normally operated when the main wing has an aspect ratio or area more than each certain value. Finally, the wing shape is determined by comparing thrust-to-power ratio of all wings satisfying the required minimum thrust. However, the stability is not secured due to moment generated by disaccord between thrust line and center of gravity. To cope with this, aerodynamic dampers are used at the top and bottom of the fuselage; then, indoor flight test was attempted for indirect performance verification of the parametric study of the main wing.

Preparation of Bismuth Telluride Thin Films using RF magnetron sputtering and Study on Their Thermoelectric Properties (RF 마그네트론 스퍼터링을 이용한 Bismuth Telluride 박막의 제조와 그 열전 특성 연구)

  • Kim, Dong-Ho;Lee, Gun-Hwan
    • Journal of the Korean Vacuum Society
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    • v.14 no.4
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    • pp.215-221
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    • 2005
  • Thermoelectric bismuth telluride thin films were prepared on $SiO_{2}$/Si substrate with co-sputtering of bismuth and tellurium targets. The effects of deposition temperature on surface morphology, crystallinity and electrical transport properties were investigated. Hexagonal crystallites were clearly visible at the surface of films deposited above $290 ^{\circ}C$. Change of dominant phase from rhombohedral $Bi_2Te_3$ to hexagonal BiTe was confirmed with X-ray diffraction analysis. The deviation from stoichiometric composition at high deposition temperature resulted in the change of structural and electrical characteristics. Seebeck coefficients of all samples have negative value, indicating the prepared $Bi_XTe_Y$ films are n-type thermoelectric. Optimum of Seebeck coefficient and power factor were obtained at the deposition temperature of $225 \^{circ}$C (about -55 $\mu$V/K and $3\times10^{-4}$ W/$k^{2}$m, respectively). Deterioration of thermoelectric properties at higher temperature.

Enhancement of Transportation Safety Service for Foreigner Residing in Ansan Through Analysis of Travel Behavior and Traffic Accident (안산거주 외국인 통행실태 및 교통사고 분석을 이용한 교통안전서비스 증진방안 연구)

  • Jung, Yong Ki;Chang, Myungsoon;Kim, Jin Tae
    • Journal of Korean Society of Transportation
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    • v.31 no.1
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    • pp.25-35
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    • 2013
  • There is a need to provide appropriate transportation safety services to foreigners residing in Korea. The main purpose of this study is to enhance transportation safety services for foreigners. In order to identify the risk of traffic accidents, analysis of traffic accidents was conducted using a survey of foreigner travel behavior. According to the results of this model, the study suggests directions to achieve improvement of traffic safety services for foreigners who are unfamiliar with the transportation systems. The study results show that the risk of traffic accidents is influenced by two factors: comprehension of transport geography and of traffic laws. Necessity of policy is influenced by two factors: comprehension of transportation system and the risk of traffic accidents. Intention of using policy is influenced by two factors: the risk of traffic accidents and necessity of policy. Effect of policy is affected by the intention of using policy. The results also demonstrate that the traffic safety services for foreigner can be described as endogenous variables which are approximately 88% of the traffic safety education, 85% of the demanded multicultural district, and 75% of the portal traffic information. Compared with existing research, this study provides a systematic methodology to evaluate effects and the order of priority in establishing traffic safety policies for foreigners.

Demand for Classical Music Concerts from Transaction Cost Perspectives (거래비용 관점으로 본 클래식 음악공연 관람수요)

  • Lee, Chang Jin;Kim, Jaibeom
    • Review of Culture and Economy
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    • v.17 no.2
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    • pp.3-28
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    • 2014
  • The characteristics of performing arts differ from those of utilitarian goods in terms of economics. Factors other than price need to be considered to understand the demand for performing arts. Audience surveys as well as econometric demand studies have confirmed that socio-economic factors such as age, income, employment, and education are major determinants of the demand for performing arts. This study focused on the attributes of concerts rather than consumer characteristics to determine the concerts audiences select in terms of transaction cost. Genre, price, internet search trends, and the purpose of performance as well as price are tested as determinants of demand by using the data set for a major concert hall in Seoul. Genre and the specific purpose of concerts influence the demand for concerts. Internet search trends of the performer are used as indicators of popularity and information exposure, which are positively correlated with demand. This result supports the hypothesis that larger audiences would attend concerts that require lower information search costs. To note, price has a positive effect on demand in the higher price range, which means that concerts at higher prices attract larger audiences, whereas normal goods have a negative slope in the demand curve. This result can be explained by the hypothesis that consumers use price as an indicator of the quality expected of a concert. Transaction cost for selecting classical concerts thus forms an inverse-U shape curve against ticket price. These results provide some explanation of why audiences of classical music choose to attend concerts at high ticket prices while offering evidence in favor of the hypothesis that performing arts are selected in a social context.

Effect of DOGO phreatic water containing germanium on Atopic Dermatitis in NC/Nga mouse (아토피양 접촉피부염 유발 NC/Nga mouse에서 도고 온천수에 첨가한 게르마늄 성분의 효과)

  • Lee, Jin-Wook;Go, Ga-Yeon;Jung, Chan-Ho;You, Sun-Jong;Kim, Yun-Hee;Ahn, Taek-Won
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.27 no.4
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    • pp.141-157
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    • 2014
  • Objectives : The purpose of this study is to investigate the effects of DOGO phreatic water containing germanium on Atopic Dermatitis in NC/Nga mouse. Methods : We made DOGO phreatic water added germanium. After making atopic dermatitis caused by sensitizing NC/Nga mouse to DNCB(dinitrochlorobenzene), we made mouse swim in tanks each filled with distilled water, tap water, DOGO phreatic water, DOGO phreatic water(added germanium) for 30minutes everyday. 3weeks later, we analyzed skin clinical score, total IgE levels(by ELISA), WBC differential counting(Neutrophils, Monocytes), absolute cell number of $Neutrophil^+Gr-1^+$, CCR3 mRNA expressions(by Real-time PCR), IL-4, IFN-${\gamma}$ production levels(by ELISA), histologic test(by H&E staining, toluidine blue staining). Results : The results of making NC/Nga mouse induced atopic dermatitis swim in tanks filled with DOGO phreatic water(contain germanium) are as follows. 1. Skin clinical scores were decreased significantly in comparison to control group. 2. Total IgG levels were decreased significantly in comparison to control group. 3. WBC differential counting(Neutrophils, Monocytes) were decreased significantly in comparison to control group. 4. Absolute cell number of $Neutrophil^+Gr-1^+$ were decreased significantly in comparison to control group. 5. CCR3 mRNA expressions were decreased significantly in comparison to control group. 6. IL-4, IFN-${\gamma}$ production levels were decreased significantly in comparison to control group. 7. The epithelial tissue thickness, leucocytes infiltration, erythema, edema, excoriation, scaling, mast cells infiltrations in dorsal skin were decreased in comparison to control group. Conclusions : These results indicate that DOGO phreatic water(contain germanium) can be used for helping treat atopic dermatitis.

Implementation of Spatial Augmented Reality Using Fog Screen (포그 스크린을 이용한 공간증강현실(SAR) 구현)

  • Park, Yoenyong;Jung, Moonryul
    • Journal of the Korea Computer Graphics Society
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    • v.25 no.3
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    • pp.43-54
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    • 2019
  • In this paper, we review the applicability of fog screen to implement 'Spatial Augmented Reality' which displays the image on the whole space of real space or in real space by separating display equipment and user, in contrast to the traditional Augmented Reality. Through three exhibitions and one performance, we confirmed t hat the fog screen, which can be passed through, is a suitable material for implementing the Spatial Augment ed Reality. We found that the hologram production was easier than before because of fog screen. Through the questionnaire survey conducted on performers along with the exhibition, we found that only about half of people know what a fog screen is, and about 10% of the total respondents saw the fog screen. In order to investigate the effect of fog screen on the surrounding space, we conducted an experiment to observe the change of humidity according to the time and distance in the Children's Culture Center of the Asian Culture Center. We found that the humidity within a radius of 5m around the fog screen could increase by 2~3%($6,400m^3$ standard). Thus we provided some safety requirement with fog screen when works made of materials vulnerable to moisture such as paint, paper, and wood are exhibited at the same time with fog screen in the exhibition hall.

A Study on the Way to Reduce Cadastral Renovation Business Period through Compensation System Improvement - Centered around the Namwon-si Cadastral Research Area - (지적재조사 조정금 산정 및 부과 방식의 개선 연구 - 남원시 지적재조사사업지구를 중심으로 -)

  • Kim, Hong-Ryeol;Min, Woong-kie
    • Journal of Cadastre & Land InformatiX
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    • v.50 no.2
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    • pp.53-68
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    • 2020
  • The Cadastral Renovation is a National project to investigate and survey the registration of Cadastral Record and replace the existing Cadastral Record with a new Cadastral Record by digital, and to correct the registration of Cadastral Record if the registration of Cadastral Record does not match the actual status of the land. The Business Period generally takes about one year and six months to two years. The time required is getting longer due to problems that occur in the course of the Adjustment amount after the cadastral resurvey survey due to complex structure and internal conflict due to the interest between landowners. After Boundary Decision of the real boundary, the land area is confirmed by the landowners, and the cadastral office is to settle the Cadastral Renovation by calculating the Adjustment amount according to the confirmed area and the increase and decrease of the cadastral area. Therefore, the solution plan was suggested so that reasonable Adjustment amount can be applied through empirical research applied to the time of calculation of Adjustment amount and the method of calculation of Adjustment amount. The improvement method showed the expected effect that can lead the agreement with the landowner to the shortest period, and it was also possible to set the real boundary that meets the purpose of the Cadastral Renovation. This study suggests improvements in the method of calculating standard Adjustment amount, the method of imposing Adjustment amount, and the method of boundary adjustment that does not impose adjustment amount through the cadastral Renovation and parallel studies, and it is expected that the Cadastral Renovation will be completed by 2030.

Effect of COVID-19 vaccinations on deaths of the COVID-19 cases in some elderly long-term care facilities, Gwangju (광주광역시 요양시설 코로나19 집단 발생 사례에서 코로나19 백신 접종에 의한 사망 예방 효과)

  • Ryu, So Yeon;Cho, Jun Hwi;Lee, Ran;Park, So Yeong;Jung, Daun;Bae, So Hyun;Ko, HwaPyeong
    • Journal of agricultural medicine and community health
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    • v.47 no.2
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    • pp.109-120
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    • 2022
  • Objectives: The purpose of this study was to identify the effectiveness of COVID-19 vaccinations on deaths of the COVID-19 cases in some elderly long-term care facilities (LTCF) in Gwangju Metropolitan City. Methods: The study subjects were 659 COVID-19 cases in residents of 7 elderly LTCF, Gwangju, from 21 Dec. 2021 to 28 Jan. 2022. The used variables were confirmed dates for COVID-19, demographic characteristics, co-morbidities, presentation of symptoms, death and vaccination related characteristics including type of vaccine, doses and dates. Vaccination status were classified as not vaccinated, partially and fully vaccinated. The associations of vaccination status and deaths of COVID-19 cases were tested by chi-square test and multiple logistic regression analysis. Results: The rates of not vaccinated, partially vaccinated and fully vaccinated were 19.4%, 10.2% and 70.4%, respectively. The mortality rate of the cases was 6.4%. The death rate by vaccination status was 16.4% in not vaccinated, 15.4% in partially vaccinated and 2.6% in fully vaccinated, showing a statistically significant difference. The adjusted odds ratios (ORs) (95% confidence intervals, CIs) of death compared to fully vaccinated were 7.64 (3.87-16.34) in non-vaccinated, and 6.97 (3.44-14.14) in partially vaccinated. Conclusions: COVID-19 vaccination seems to work effectively in preventing deaths of COVID-19 cases of elderly LTCF residents. This finding support that fully vaccinations in high risk group such as elderly LTCF residents is very important for one of strategies of COVID-19 management.