• Title/Summary/Keyword: 지가 변화

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Control of Suspended Dust in Various Ventilation Systems of Cement Packaging Process (시멘트 포장공정에서 환기시스템에 따른 발생분진의 제어)

  • Lee, Seung-Chul;Kim, Soo-Chang;Noh, Kwang-Chul;Park, Myoung-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.3
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    • pp.463-469
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    • 2009
  • We performed the experimental study on the control of suspended dust in a cement packaging process for various ventilation systems. To effectively remove the dust generated in the cement packaging process, three different kinds of ventilation system, such as local exhaust ventilation, electrostatic scrubber, and local air supply system, were adopted. Dust concentrations in the packaging process were measured with the variation of the airflow rate of the ventilation systems and then their ventilation performance were evaluated. From the results, we knew that the ventilation performance was the best when the local exhaust ventilation and the electrostatic scrubber were simultaneously operated in the packaging process. In the electrostatic scrubber system, the effect of the airflow rate on the indoor dust removal efficiency was negligible so hat he system ust be operated at $2,700m^3/h$ for saving power consumption.

Formulation and Application of UV-Cured Hard Coating Compounds for PVC Tile (PVC 바닥상재용 광경화형 하드 코팅액의 제조 및 응용에 관한 연구)

  • Park, Bo-Ram;Yoon, Hyun-Jung;Zhao, Hong;Ha, Jin-Wook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.9
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    • pp.2396-2401
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    • 2009
  • This study is on development of UV-cured hard coating compounds which have more improved abrasion resistance than existing UV-cured urethane-acrylic resin, to prevent a surface of a widely used PVC tile as a constructive material from being scratched. To make a high abrasion resistant hard coating solution compared to UV-cured urethane-acrylic resin which has no abrasion resistance and been used for PVC tiles, we added powder substances of different abrasion resistant level, $Al_2O_3$(Al-160SG-3), $Al(OH)_3$(SH-8W), $SiO_2$(KS-5000), etc., to the resin, changing their contents from 10% to 30% against quantities of resin, and compounded it using Ring-Mill. After coating PVC tiles with the hard coating solution using bar-coating method that can adjust a thickness, we estimated some surface properties-abrasion resistance, pencil hardness, adhesive power, thickness of coating, and so on. As a result, a hard coating solution added 30% $Al_2O_3$ powder to the resin had the finest surface properties-the first grade in abrasion resistance, H in pencil hardness, 100% in adhesive power, and a hard coating solution which showed excellent solidity and abrasion resistance has smaller particle size, higher powder content, and thicker coating thickness.

A Study on Microbial Pollution of Indoor Air at Elderly Care Facilities (노인요양시설의 실내공기 중 미생물 오염에 관한 연구)

  • Kim, Sang-Ha;Kim, Young-Kwon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.9
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    • pp.2485-2491
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    • 2009
  • Culture was performed by using Sheep Blood Agar Plate (BAP, Asan Pharmaceutical) and Sabouraud Dextrose Ager (SDA, Asan Pharmaceutical) along with air $IDEAL^{TM}$ (Biomerieux), which is a microbe interceptor based on inertial impaction interception, in order to investigate bioaerosol in indoor and outdoor air at five elderly care facilities in a metropolis and an urban-rural consolidated city for two months from April 1 to May 31, 2007. From the culture followed by isolation and identification, the following conclusions were drawn. 1. As for the general isolation of microbes in each facility, care center S had the largest amount of microbes (263 cfu/$m^3$) isolated in a 300L room, followed by care center U having 123 cfu/$m^3$ isolated. 2. As for the number of bacteria isolated from a medium intercepting 300 L indoor, the largest amount of other unidentified or non-pathogenic Gram positive cocci (321 cfu/$m^3$) was isolated and most of the other Gram positive cocci were CNS (Coagulase Negative Staphylococcus). 3. As for the number of fungi isolated from a medium intercepting 300 L in a room, the largest number of Aspergillus spp. (66) was isolated, followed by Mucor spp. (62 cfu/$m^3$), Penicillium spp. (53 cfu/$m^3$), Alternaria spp. (50), and other unidentified or non-pathogenic fungi (42 cfu/$m^3$). 4. As for the rate of indoor and outdoor pollution, the average number of interceptions was all larger indoor than outdoor; the research differentiating the amount of air into 300 L and 500 L demonstrated that the larger amount of air led to more bacteria, making no great variation in the species.

Effects of Taping Therapy by Methods on Back Pain and Muscle Flexibility of Bus Drivers's (테이핑 적용방법에 따른 버스 운전기사의 요통과 근 유연성에 미치는 효과)

  • Park, Min-Chull;Kim, Eun-Young;Ha, Mi-Sook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.11
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    • pp.4367-4373
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    • 2010
  • The purpose of this study was to compared the effectiveness of erector spine taping and lumbar taping maintained in bus driver's back pain. The research subjects were some bus drivers working in Changwon, Masan, and Busan terminal. And we concluded this research; By selecting a group of 15 people taping erector spine, a group of lumbar taping, and a control group of 15 people randomly. Because we measured them before treatment and two weeks after treatment by the time, we could get the results which were as follows. The experiment group applied of taping therapy would be reduced in back pain when compared to the control group. The experiment group applied of taping therapy would be improved in muscle flexibility when compared to the control group. After treatment, the experiment group compared to control group showed decrease pain and an increase of flexibility. In conclusion, we could know that taping reduces back pain of bus drivers and gives a positive impact to muscle flexibility improvement, we finded out a distinct difference between the erector spine taping and the lumbar taping. Thus, the taping treatment can be applied easily to the bus driver and used as a way of therapeutic approach.

The relationship between lifestyle and sodium intake in Korean middle-aged workers (한국 중년 직장인의 나트륨 과다섭취 특성과 영향요인)

  • Kim, Myung-Gwan;Kim, Keon-Yeop;Nam, Hang-Me;Hong, Nam-Soo;Lee, Yu-Mi
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.5
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    • pp.2923-2929
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    • 2014
  • This research was conducted to grasp the characteristics of excessive sodium intake and its related factors in Korean middle-aged workers to help prevent and manage cardio-cerebrovascular disease. Study subjects were 40-59-year-old workers (n=1,438) who took part in the 2010 Korean National Health and Nutrition Examination Survey (KNHANES). Subjects were divided into: 1) a group that ingested more than 4,000 mg of sodium per day and 2) a group that ingested less than 4,000mg of sodium/day. We analyzed the relationship between general characteristics, sodium-related disease, health behaviors, and frequency of eating out with excessive sodium intake. The proportion of subjects with sodium intake of more than 4,000 mg/day was high in men, smokers, and drinkers. As educational level and frequency of eating out went up, so did the proportion of subjects with sodium intake more than 4,000 mg/day. It's necessary to educate the public and create policies regarding sodium reduction in middle-aged men for the prevention and management of cardio-cerebrovascular disease, and various approaches are necessary to reduce overall sodium intake in the restaurant environment.

A study on ecosystem model of the magazines for smart devices Focusing on the case of magazine business in foreign countries (스마트 디바이스 잡지 생태계 모델 연구 - 외국 잡지의 비즈니스 사례를 중심으로)

  • Chang, Yong Ho;Kong, Byoung-Hun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.5
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    • pp.2641-2654
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    • 2014
  • In the smart media environment, magazine industry has been experiencing a transition to ecosystem of value network, which includes high complexity and ambiguity. Using case study method, this article conducts research on digital convergence, the model of magazine ecosystem and adaptation strategy of global magazine companies. Research findings have it that the way of contents production of global magazines has been based on collaborative production system within communities, expert communities, creative users, media contents companies and magazine platform. The system shows different patterns and characteristics depending on magazine-driven platform, Platform-driven platform or user-driven platform. Collaboration system has been confirmed in various cases: Huffington Post and Zinio which collaborate with media contents companies, Amazon magazines and Bookish with magazine companies, Huffington Post and Wired with expert communities, and Flipboard with creative users and communities. Foreign magazine contents diverge into (paper, electronic, app and web magazine) as they start the lively trades of their contents on the magazine platform. In the area of contents uses, readers employ smart media technology effectively such as cloud computing, artificial intelligence and module individualization, making it possible for the virtuous cycle to remain in the relationship within communities, expert communities and creative users.

A Study on the Volatile Change of Essential Oils Addition on to the Vegetable Fatty Acid Hard Soap (식물성 지방산 고형비누에 첨가된 에센셜오일의 휘발성 변화에 대한 연구)

  • Lee, Sung-Hee;Lee, Ki-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.5
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    • pp.3304-3311
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    • 2014
  • In the saponification to manufacture plant fatty acid hard soap, the drying process is required for its water evaporation and hardness. This study mixed it with essential oil(E.O) with high volatility instead of adding synthetic flavor. And it comparatively observed the duration of flavor changing to the additive ($TiO_2$) and the drying period of the major flavor component (Linalool, Linalyl acetate) in the essential oil (Lavender E.O) contained in the soap during the soap manufacture by using GC-MS. Advanced researches have mostly dealt with the utility of plant hard soap, and those related with the volatility of flavor have been hardly conducted. Regarding the volatility of linalool contained in the soap, the soap mixed with $TiO_2$ showed a higher reduction ratio up to the 12th week; however, at the point of the 20th week, it reduced to a similar level. Although Linalyl acetate did indicate a slight difference according to the mixture of $TiO_2$, the volatility was shown similar up to the point of the 20th week. During the 20 weeks of drying, the residual rate of linalool was found to be higher than that of Linalyl acetate regardless of the mixture of $TiO_2$. It has been found that the flavor component of lavender essential oil with the duration of two or so days at the room temperature remains for 20 weeks (or 5 months) when it is manufactured through the mixture of plant fatty acid hard soap.

Analysis of quality improvement effects by construction of sewer systems in Nam River Basin (남강 상류유역의 하수도시설 확충으로 인한 하류 수계의 수질개선 효과 분석)

  • Joo, Jin-Gul;Lee, Jung-Ho;Kim, Joong-Hoon;Kim, Eung-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.3
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    • pp.771-778
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    • 2008
  • Effects of establishments of more sewer systems on water quality in Nam River, Deokchun River, and Jinyang Lake were analyzed for various scenarios using QUAL2E, WASP 7 water quality model. Three different scenarios were tested: 1) 20.8% of sewer diffusion rate which is same to the existing condition. 2) Expansion of sewer system to 65.2% which would emit less pollutants, BOD 2350.5 kg/d, TN 216.0 kg/d, TP 44.0kg/d. 3) Pollutants emission to maintain first grade water quality in Nam River, Jinyang Lake, BOD and TN in the case 2 were 7.69%, 2.10% lower than those in the case 1 in the Nam River. And in the Jinyang Lake, BOD, TN, and TP in the case 2 were 10.25%, 1.37%, 2.94% lower than those in the case 1. However the simulations showed that water quality could not hold down first grade water quality standard level with the establishments of more sewer systems. To satisfy the criteria in the Nam River and Jinyang Lake, BOD emission must be reduced 27.2%, 37.05% compared to those in the case 1.

Numerical Study on Thermal Performances of Multi Heat Source Heating System Using Butane for Electric Vehicle (전기자동차용 부탄 연료 복합열원 히팅시스템의 열적 성능에 관한 수치적 연구)

  • Bang, You-Ma;Seo, Jae-Hyeong;Patil, Mahesh Suresh;Cho, Chong-Pyo;Lee, Moo-Yeon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.10
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    • pp.725-731
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    • 2016
  • This study numerically investigates the thermal performance of a 2.0-kW butane-based combustion heating system for an electric vehicle under cold conditions. The system is used for cabin space heating and coolant-based battery thermal management. ANSYS CFX 17 software was used for parametric analysis. The mass flow rates of cold air and coolant were varied, and their effects were compared. The numerical results were validated with theoretical studies, which showed an error of 0.15%. As the outside air mass flow rates were increased to 0.005, 0.01, and 0.015 kg/s, the cabin supply air temperature decreased continuously while the coolant outlet temperature increased. When the coolant mass flow rates were increased to 0.005, 0.01 and 0.015 kg/s, the air temperature increased while the coolant outlet temperatures decreased. The optimal mass flow rates are discussed in a consideration of the requirements for high cabin heating capacity and efficient battery thermal management.

A Study on Velocity Distribution Characteristics for Each Location and Effectiveness of Straight Duct Length in a Square-sectional 180° Bended Duct (정사각형 단면을 갖는 180° 곡관에서 위치별 속도분포특성 및 직관거리의 유효성에 관한 연구)

  • Chen, Jing-Jing;Yoon, Jun-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.10
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    • pp.618-627
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    • 2016
  • This study numerically analyzes the characteristics of the velocity distribution for each location of a square-sectional $180^{\circ}$ bent duct using a Reynolds Stress Turbulent model. The flow parameters were varied, including the working fluids, inlet velocity, surface roughness, radius of curvature, and hydraulic diameter. The boundary conditions for computational fluid dynamics analysis were inlet temperatures of air and water of 288 K and 293 K, inlet air velocity of 3-15 m/s, inner surface roughness of 0-0.001 mm, radius of curvature of 2.5-4.5 D, and hydraulic diameter of 70-100 mm. The working fluid characteristics were highly affected by changes in the viscous force. The maximum velocity profiles in the bent duct were indicated when the $90^{\circ}$ section was in the region of X/D=0.8 and the $180^{\circ}$ section was in the region of Y/D=0.8. Lower surface roughness and higher radius of curvature resulted in a higher rate of velocity change. Also, an efficient measuring location downstream of the bent duct is suggested since the flow deviations were the most stable when the straight duct length was in the region of L/D=30. The minimum deviations at the same velocity conditions according to the hydraulic diameter were mostly indicated in the range of L/D=15-30 based on the standard deviation characteristics.