• Title/Summary/Keyword: Contact Mass

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Sexual Behavioral Characteristics and the Knowledge of HIV/AIDS among Men who have Sex with Men in Republic of Korea (한국 남성 동성애자들의 성행태와 후천성면역결핍증에 대한 인식)

  • Kee, Mee-Kyung;Park, Chul-Min;Chang, Chang-Gok;Go, Un-Yeong
    • Journal of Preventive Medicine and Public Health
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    • v.37 no.3
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    • pp.220-224
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    • 2004
  • Objectives : To investigate the sexual behavioral characteristics and HIV/AIDS knowledge among men who have sex with men(MSM), one of the HIV high risk groups. Methods : A three month survey among individuals who were able to be contacted was carried out over the entire Republic of Korea, between May and August, 2001. 348 individuals completed a self-administered question-naire. The data collected included demographic informa-tion, sexual behavior and AIDS knowledge. Results : Eighty-seven and ninety-two per cent of the 348 MSM were aged 20-39 years and had never been married, respectively. Fifty-five per cent of participants reported at least one sexual contact with women, and a quarter of the MSM surveyed had engaged in high-risk sexual behavior (more than 6 partners) during the previous year. About twenty per cent of the MSM had anal sex as their favorite way of having sex, and seventy-four per cent did not use condoms regularly due to loss of enjoyment, and were more likely to be engaged in risky behaviors. Only ten per cent had a regular HIV test history, and most had obtained knowledge or information on HIV/AIDS through the mass media. Conclusions : A large proportion of the MSM in Korea still remain at an elevated risk for contracting HIV infection. Change in high-risk sexual behaviors will prevent the spread of HIV infection among the MSM population, which requires public health education for preventive interventions, and should be culturally and socially specific in order to be effective.

Wet Foam Stability from Colloidal Suspension to Porous Ceramics: A Review

  • Kim, Ik Jin;Park, Jung Gyu;Han, Young Han;Kim, Suk Young;Shackelford, James F.
    • Journal of the Korean Ceramic Society
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    • v.56 no.3
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    • pp.211-232
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    • 2019
  • Porous ceramics are promising materials for a number of functional and structural applications that include thermal insulation, filters, bio-scaffolds for tissue engineering, and preforms for composite fabrication. These applications take advantage of the special characteristics of porous ceramics, such as low thermal mass, low thermal conductivity, high surface area, controlled permeability, and low density. In this review, we emphasize the direct foaming method, a simple and versatile approach that allows the fabrication of porous ceramics with tailored microstructure, along with distinctive properties. The wet foam stability is achieved under the controlled addition of amphiphiles to the colloidal suspension, which induce in situ hydrophobization, allowing the wet foam to resist coarsening and Ostwald ripening upon drying and sintering. Different components, like contact angle, adsorption free energy, air content, bubble size, and Laplace pressure, play vital roles in the stabilization of the particle stabilized wet foam to the porous ceramics. The mechanical behavior of the load-displacements curves of sintered samples was investigated using Herzian indentations testes. From the collected results, we found that microporous structures with pore sizes from 30 ㎛ to 570 ㎛ and the porosity within the range from 70% to 85%.

Frank Lloyd Wright's Houses in relation to the Earth and the Sky (라이트의 주택에 나타난 대지와 하늘의 인식에 관한 연구)

  • Kim, Tai Young
    • Journal of the Korean Institute of Rural Architecture
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    • v.18 no.3
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    • pp.1-8
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    • 2016
  • Frank Lloyd Wright(1867-1959) had the confident concept that architecture should be at home in nature. His architecture was meant to bear an intimate relation to the earth and the sky, and should look as though it began there at the ground and contrasted with the sky. In handling all the details of house design elements, his efforts for being married to the ground was to conceive the void of the sky. This study is to research his thinking process and its development to the earth and the sky, and to analyze how such thought could reflect his houses. The mass of house are divided into three parts such as the foundation or base, body, and roof. These parts are respectively related to the earth and the sky. This study goes on regarding them as an analytical framework. The subjects of study are the Prairie houses in the early 20th century and the Usonian houses after 1930's. As results of this study, the earlier foundation as a platform appeared as a base and water table, and a strong baseline pressed the structures into the soil in the Prairie houses. The direct contact of wood and brick to ground were dominant details after Wiley house(1934). The base was almost invisible to the eye in the Usonian houses. Secondly, the pierlike shapes and delicate friezes of walls were anchored to the ground, and horizontal bands as trims or copings also got close to the earth. These characters had disappeared after the Allen house(1917), all components including exterior walls had been unified with the grid patterns in the Usonian houses. Thirdly, the overhanging cantilever roof had got to the earthbound by the reflection of shadow as well as their evident horizontal. He lowered the roof, lengthened and brought it closer to the ground. In this way, Frank Lloyd Wright intended his houses to be at home in nature. And also he tried to bind the houses to the earth and contrasted them with the sky. The houses would perform their highest function in relation to the earth and sky.

A study of the subtitles abuse cases of entertainment programs (예능프로그램의 보조자막 오남용에 관한 연구)

  • Yun, Na-Ra;Kang, Hyo-Soon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2011.10a
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    • pp.869-871
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    • 2011
  • For people who live in 'the Media Age', contact with the media is indispensable. In various mass media, especially TV, it is the most familiar and influential media, because it is easy to access and used regardless of age or gender. However, in many recent TV programs the subtitles of the misuse and abuse problems are pointed out. In the popular entertainment programs, and dramas, the problems are the most serious. Many entertainment programs organized during prime time have largely a family audience. Thus, the effects and responsibilities according to subtitles should be accompanied. The subtitles are an element that make up the entertainment program. In this study, the abuse cases of subtitle usage were analyzed. This study is aimed at maximizing the proper function of the subtitles, and creating fun and laughter through reducing misuses in various entertainment programs.

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Aerodynamic Approaches for the Predition of Spread the HPAI (High Pathogenic Avian Influenza) on Aerosol (고병원성 조류인플루엔자 (HPAI)의 에어로졸을 통한 공기 전파 예측을 위한 공기유동학적 확산 모델 연구)

  • Seo, Il-Hwan;Lee, In-Bok;Moon, Oun-Kyung;Hong, Se-Woon;Hwnag, Hyun-Seob;Bitog, J.P.;Kwon, Kyeong-Seok;Kim, Ki-Youn
    • Journal of The Korean Society of Agricultural Engineers
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    • v.53 no.1
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    • pp.29-36
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    • 2011
  • HPAI (High pathogenic avian influenza) which is a disease legally designated as an epidemic generally shows rapid spread of disease resulting in high mortality rate as well as severe economic damages. Because Korea is contiguous with China and southeast Asia where HPAI have occurred frequently, there is a high risk for HPAI outbreak. A prompt treatment against epidemics is most important for prevention of disease spread. The spread of HPAI should be considered by both direct and indirect contact as well as various spread factors including airborne spread. There are high risk of rapid propagation of HPAI flowing through the air because of collective farms mostly in Korea. Field experiments for the mechanism of disease spread have limitations such as unstable weather condition and difficulties in maintaining experimental conditions. In this study, therefore, computational fluid dynamics which has been actively used for mass transfer modeling were adapted. Korea has complex terrains and many livestock farms are located in the mountain regions. GIS numerical map was used to estimate spreads of virus attached aerosol by means of designing three dimensional complicated geometry including farm location, road network, related facilities. This can be used as back data in order to take preventive measures against HPAI occurrence and spread.

Development of a High speed Actuator for electric performance testing System of ceramic chips (세라믹칩 전기적 성능검사 시스템을 위한 고속구동 액튜에이터 개발)

  • Bae, Jin-Ho;Kim, Sung-Gaun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.4
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    • pp.1509-1514
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    • 2011
  • The core of IT products, electronic components, especially the MLCC, chip inductors, chip Varistors and so on. In order to test the electrical characteristics of the chip using the Reno-pin contact test method has been used. In current chips, mass production of semiconductor manufacturing processes, high-speed production test for the chip speed up, precision is required. But Vibration displacement is a very short, so in order to overcome these shortcomings, the displacement amplification to design the structure has been actively studied. In this paper, a building structure with a flexible hinge was designed amplification instrument, semiconductor chip industry in the performance test and inspection equipment to measure the electrical characteristics of high speed linear actuators Reno-Pin using system was developed.

Characteristics of Calcium Leaching Resistance for Concrete Mixed with Mineral Admixture (광물질 혼화재를 혼합한 콘크리트의 칼슘용출 저항 특성)

  • Choi, So-Yeong;Choi, Yoon-Suk;Yang, Eun-Ik
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.20 no.4
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    • pp.59-67
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    • 2016
  • Concrete is a very useful construction material for the sealing disposal of hazardous substances. In general, mass concrete is applied to these structures. And, the mineral admixtures are recommended for the long term performance. Calcium leaching could be happened due to the contact with pure water in underground structures. Thus, it is needed to evaluate the resistance of calcium leaching for concrete mixed with mineral admixtures. From the test results, the mineral admixtures are effective to the improvement of long term compressive strength and chloride diffusion coefficient in concrete members. When calcium leaching is happened, however, the reduction of compressive strength and chloride penetration resistance is severe than OPC case, the micro pore distribution is adversely affected. Consequently, when the mineral admixtures are applied to underground structures which is exposed to calcium leaching environment, it is desirable to reduce water-to-binder ratio, to expose after the sufficient pozolanic reaction, and to use BFS than FA.

Ground Reaction Force Characteristics During Forward and Backward Walking Over 20 Degree Ramp (20° 경사로 앞.뒤 보행 동작 시 지면반력의 형태 비교 분석)

  • Chae, Woen-Sik
    • Korean Journal of Applied Biomechanics
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    • v.18 no.3
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    • pp.71-82
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    • 2008
  • W. S. CHAE, Ground Reaction Force Charateristics During Forward and Backward Walking Over 20 Degree Ramp. Korean Journal of Sport Biomechanics, Vol. 18, No. 3, pp. 71-82, 2008. The purpose of this study was to compare GRF characteristics during forward and backward walking over 20 degree ramp. Temporal parameters, GRFs, displacement of center of pressure (DCP), and loading and decay rates were determined for each trial. The results showed that the vertical GRF in BD during RTO was significantly greater than those found in FU. This reults indicated that GRF patterns may be changed by different walking conditions and altering position of ankle, knee, and center of mass throughout the walking cycle. The DCP during $RHC_2$-LHC in antero-posterior direction for downward was smaller than the corresponding value for upward condition. It' seems that the ankle and knee joints are locked in an awkward fashion at the toe contact to compensate for imbalance. Reducing the magnitude of loading rate can be achieved by walking in the backward direction. Accordingly, the results can be a benefit if one is suffering from an impact-type injury.

Relationship between Impact and Shear Forces, and Shock during Running (달리기 시 충격력과 충격 쇼크 변인들과의 관계)

  • Park, Sang-Kyoon;Ryu, Ji-Seon
    • Korean Journal of Applied Biomechanics
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    • v.30 no.2
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    • pp.145-154
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    • 2020
  • Objective: The purpose of this study was to determine the relationship between impact and shear peak force, and tibia-accelerometer variables during running. Method: Twenty-five male heel strike runners (mean age: 23.5±3.6 yrs, mean height: 176.3±3.3 m/s, mean mass: 71.8±9.7 kg) were recruited in this study. The peak impact and anteroposterior shear forces during treadmill running (Bertec, USA) were collected, and impact shock variables were computed by using a triaxial accelerometer (Noraxon, USA). One-way ANOVA was used to test the influence of the running speed on the parameters. Pearson's partial correlation was used to investigate the relationship between the peak impact and shear force, and accelerometer variables. Results: The running speed affected the peak impact and posterior shear force, time, slope, and peak vertical and resultant tibial acceleration, slope at heel contact. Significant correlations were noticed between the peak impact force and peak vertical and resultant tibia acceleration, and between peak impact average slope and peak vertical and resultant tibia acceleration average slope, and between posterior peak (FyP) and peak vertical tibia acceleration, and between posterior peak instantaneous slop and peak vertical tibial acceleration during running at 3 m/s. However, it was observed that correlations between peak impact average slope and peak vertical tibia acceleration average slope, between posterior peak time and peak vertical and resultant tibia acceleration time, between posterior peak instantaneous slope and peak vertical tibial acceleration instantaneous slope during running at 4 m/s. Conclusion: Careful analysis is required when investigating the linear relationship between the impact and shear force, and tibia accelerometer components during relatively fast running speed.

Fuel-Coolant Interaction Visualization Test for In-Vessel Corium Retention External Reactor Vessel Cooling (IVR-ERVC) Condition

  • Na, Young Su;Hong, Seong-Ho;Song, Jin Ho;Hong, Seong-Wan
    • Nuclear Engineering and Technology
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    • v.48 no.6
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    • pp.1330-1337
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    • 2016
  • A visualization test of the fuel-coolant interaction in the Test for Real cOrium Interaction with water (TROI) test facility was carried out. To experimentally simulate the In-Vessel corium Retention (IVR)- External Reactor Vessel Cooling (ERVC) conditions, prototypic corium was released directly into the coolant water without a free fall in a gas phase before making contact with the coolant. Corium (34.39 kg) consisting of uranium oxide and zirconium oxide with a weight ratio of 8:2 was superheated, and 22.54 kg of the 34.39 kg corium was passed through water contained in a transparent interaction vessel. An image of the corium jet behavior in the coolant was taken by a high-speed camera every millisecond. Thermocouple junctions installed in the vertical direction of the coolant were cut sequentially by the falling corium jet. It was clearly observed that the visualization image of the corium jet taken during the fuel-coolant interaction corresponded with the temperature variations in the direction of the falling melt. The corium penetrated through the coolant, and the jet leading edge velocity was 2.0 m/s. Debris smaller than 1 mm was 15% of the total weight of the debris collected after a fuel-coolant interaction test, and the mass median diameter was 2.9 mm.