• Advances in environmental research
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• 제2권1호
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• pp.61-80
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• 2013

Quantification of viable forms of microbial community (bacteria and fungi) using culture-dependent methods was done in order to characterize the indoor air quality (IAQ). Role of those factors, which may influence the concentration of viable counts of bacteria and fungi, like ventilation, occupancy, outdoor concentration and environmental parameters (temperature and relative humidity) were also determined. Volumetric-infiltration sampling technique was employed to collect air samples both inside and outside the schools. As regard of measurements of airborne viable culturable microflora of schools during one academic year, the level of TVMCs in school buildings was ranged between 803-5368 cfu/$m^3$. Viable counts of bacteria (VBCs) were constituted 63.7% of the mean total viable microbial counts where as viable counts of fungi (VFCs) formed 36.3% of the total. Mean a total viable microbial count (TVMCs) in three schools was 2491 cfu/$m^3$. Outdoor level of TVMCs was varied from 736-5855 cfu/$m^3$. Maximum and minimum VBCs were 3678-286 cfu/m3 respectively. Culturable fungal counts were ranged from 268-2089 cfu/$m^3$ in three schools. Significant positive correlation (p < 0.01) was indicated that indoor concentration of viable community reliant upon outdoor concentration. Temperature seemed to have a large effect (p < 0.05, p < 0.01) on the concentration of viable culturable microbial community rather than relative humidity. Consistent with the analysis and findings, the concentration of viable cultural counts of bacteria and fungi found indoors, were of several orders of magnitude, depending upon the potential of local, spatial and temporal factors, IO ratio appeared as a crucial indicator to identify the source of microbial contaminants.

• 패션비즈니스
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• 제19권4호
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• pp.92-108
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• 2015

This study aimed at developing a down jacket prototype that utilized sunlight as an alternative energy source with no air pollution. The jacket is filled with flexible solar panels and has a heat-generating function and LED function. In this study, three smart down jacket prototypes were developed, and the jacket's capabilities were demonstrated through the thermal effect on the performance test. The typical output voltage of the flexible solar panels was 6.4V. By connecting the 2 solar cell modules in series, the final output voltage was 12.8V. A battery charge regulator module was used the KA 7809 (TO-220) of 9V. Three heating pads were to be inserted into the belly of the jacket as direct thermal heating elements, and the LED module was configured, separated by a flash and an indicator. The smart down jacket was designed to prevent damage to the down pack without the individual devices' interfering with the human body's motion. Because this study provides insulation from extreme cold with a purpose, the jacket was tested for heat insulation properties of non-heating, heating on the back, heating on the abdomen, and heating on both the back and abdomen in a sitting posture in a static state. Thermal property analysis results from examining the average skin temperature, core temperature, and the temperature and humidity within clothing showed, that placing a heating element in one place was more effective than distributing the heating elements in different locations. Heating on the back was the most effective for maintaining optimal skin temperature, core temperature, and humidity, whereas heating on the abdomen was not effective for maintaining optimal skin temperature, core temperature, or humidity within clothing because of the gap between the jacket and the body.

• 생물환경조절학회지
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• 제18권3호
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• pp.215-224
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• 2009

공기유동 제어기술의 개발을 위한 기초자료를 제공 할 목적으로 토마토 재배 온실의 냉난방과 환기 및 공기유동 관련 실태를 조사하고, 온실유형과 난방방식별 온습도 분포를 실측하여 균일도를 분석하였다. 충남 부여 세도지역의 토마토 재배 온실 136농가를 대상으로 조사한 결과 대부분을 차지하는 단동 플라스틱 온실의 천창 설치 비율이 낮고 환기팬과 유동팬 설치비율도 매우 낮을 뿐만 아니라 설치제원도 편차가 매우 큰 것으로 나타났다. 아치형 단동 플라스틱온실의 천창 환기 구조의 개발보급과 연동곡부의 천창도 지붕상부로 이동시킬 필요가 있으며, 개별 천창구조 및 환기팬과 유동팬에 대한 설치 가이드라인의 제정이 요구된다. 냉방설비를 설치한 농가는 하나도 없었으며 난방방식의 대부분을 차지하는 온풍난방에서 덕트의 설치제원 역시 편차가 큰 것으로 나타났고, 온풍덕트의 배기풍속 및 배기온도 또한 거리에 따른 편차가 매우 큰 것으로 관측되었다. 수출경쟁력 화보를 위한 고품질의 생산물을 연중 안정적으로 생산하기 위해서는 온실냉방기술의 보급이 절실하며 난방방식이나 덕트설치 방식의 개선이 필요한 것으로 판단된다. 온실내 온습도 분포가 균일한지 여부를 판단하는 지표로 사용되고 있는 최대 편차와 실제 균등한 정도를 나타낼 수 있는 균일도와의 관계를 분석해 본 결과 높은 상관관계를 보였으나 주간에는 직선식으로 야간에는 2차 곡선식으로 다르게 표현되었다. 온습도 분포의 균일한 정도를 판정할 수 있는 객관적인 기준이 마련된다면 최대편차 대신 균일도를 지표로 사용하는 것이 더 합리적일 것으로 판단된다. 온실유형과 난방방식에 따라 온 습도분포의 균일도가 상당히 다른 것을 확인할 수 있었으며 야간에는 온수난방의 경우 이랑배관으로, 온풍난방의 경우 온풍덕트의 적절한 배치를 통하여, 주간에는 환기와 공기유동을 통하여 균일도를 개선할 수 있을 것으로 판단되었다.

• 한국멀티미디어학회논문지
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• 제12권10호
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• pp.1478-1485
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• 2009

주변 환경을 감시하도록 구축된 센서 네트워크는 다양한 감지 작업을 수행하는 센서들로 구성되어 있으며 다양한 분야에서 적용되고 있다. 센서 네트워크는 가정 자동화, 화재감지 및 보안 분야 등기 다양한 응용분야에서 광범위하게 사용되고 있으며, 적절한 기능을 가지는 센서의 개발과 적합한 응용을 위한 네트워크 구축이 활발하게 추진되고 있다. 본 논문에서는 작업자의 안전을 위협하는 요소가 많은 작업현장에 센서 네트워크를 구축하여 각종 설비 현황을 모니터링 하도록 시스템을 설계하고 구현한다. 작업환경을 모니터링 하는 센서는 온도, 습도 데이터를 수집하여 싱크 노드에게 전송하고, 싱크노드와 연결된 서버는 데이터를 수집하여 사용자 인터페이스를 통해 작업자에게 제공한다. 또한, 작업현장에서 발생하는 디지털 데이터는 작업의 효율성을 높일 수 있도록 센서네트워크를 경유하여 전달된다. 제안하는 센서 네트워크는 음식물 폐기업체에 적용되어 음식 폐기물의 온도와 습도를 모니터링하고 업체에 출입하는 트럭의 중량 정보를 전송하여 작업의 편의성을 증대한다.

• 한국군사과학기술학회지
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• 제19권5호
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• pp.669-674
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• 2016

The purpose of this study is to demonstrate the suitability of hydrogen peroxide($H_2O_2$) vapor system for platform interior decontamination. Geobacillus stearothermophilus biological indicator(BI) strips and a field tent were used as a biological simulant and as a simulated platform, respectively. Decontamination was performed based on injection rates and tent sizes with exposure time 60 minutes. We standardized the conditions for the field tent decontamination : 8.0 g/min for $30m^3$($H_2O_2$ vapor concentration of 150~500 ppm, relative humidity of 50 %) and 12.0 g/min for $60m^3$($H_2O_2$ vapor concentration of 250~400 ppm, relative humidity of 55 %). Thus we suggest the system is one of the possible candidates for decontamination of platform interiors.

• 한국환경보건학회지
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• 제39권3호
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• pp.279-288
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• 2013

Objectives: Effectiveness and conditions of vapor-phase hydrogen peroxide (VPHP) system on decontamination of Geobacillus stearothermophilus(GS) spores, Escherichia coli (E.coli) and Enterobacteria phage felix01 (felix01) were determined. Methods: The VPHP system was designed to vaporize 35% (w/w) solution of hydrogen peroxide, continuously to inject and withdraw VPHP. The system and VHP 1000ED (Steris) were operated such that dehumidification and conditioning were initiated without samples in the chamber. Then the samples were loaded into and removed. Coupons (glass, anodizing, silicon, viton) with GS spores ($1{\times}10^6$ colony forming unit/mL [CFU/mL]), E.coli ($1{\times}10^7$ CFU/mL) and felix01 ($1{\times}10^7$ plaque forming unit/mL[PFU/mL]), and Biological Indicator (BI) with GS spores ($1{\times}10^6$ CFU/mL) on stainless steel coupons were used. The tested samples were sonicated and vortexed, and then were plated for enumeration, followed by incubation at $55^{\circ}C$, 24 hr for GS spores, and at $37^{\circ}C$, 24 hr for E.coli and felix01. BI analysis in broth culture was only qualitative. Results: The efficacy of the VPHP system on decontamination was almost equivalent to that of VHP 1000ED. The conditions for complete decontamination with the VPHP system was as follows: concentration; 700~450 ppm, relative humidity; approximately 55%, and temperature; $34{\sim}32^{\circ}C$. When comparing the decontamination efficiency among different kinds of coupons, glass was the most effective, however, all kinds of coupons were decontaminated completely after 60 min exposure in both systems. Conclusion: The VPHP system can be recommended as an alternative system for traditional system using ethylene oxide, formaldehyde or chlorine dioxide.

• 한국산림과학회지
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• 제100권2호
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• pp.240-245
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• 2011

강원도 남부 지역의 발달단계가 다른 소나무림 벌채지에서 16년 동안의 식생 변화를 연구하였다. 교란 후, 천이 궤적 및 환경 변화를 온도, 상대습도, 서열분석(Detrended Correspondence Analysis, DCA), Multiple Responses Permutation Procedure(MRPP) 및 지표종 분석(Indicator Species Analysis, ISPAN) 등을 통하여 분석하였다. 벌채 직후, 수관열림도는 대조구와 비교하여 세 배(1yr 68.3% 및 R1 23.0%)로 급격히 증가한 후 감소하였으나, 상대습도는 비교적 작은 변화(약 6% 감소)를 나타내었다. DCA 결과, 벌채 후 초기에는 종조성이 이질적으로 변화하였으나, 점차 벌채 이전(대조구)의 것과 유사하게 발달하였다. MRPP 결과, 각 발달 단계(1yr, 3yr, 10yr 및 16yr)의 종 조성은 대조구(R1, R3, R10 및 R16)의 것과 유의한 차이를 보였다. 1yr 및 3yr에서는 목본성 종이, 10yr 및 16yr에서는 초본 종들이 주요 종으로 분석되어, 교란 직후에는 목본성 종들이 활발한 재생을 나타내며, 이후 초본 식생이 발달하는 것을 보였다. 연구 대상지역의 천이는 초기 식물상 조성 모델로 설명할 수 있을 것으로 판단된다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2004년도 학술.기술논문발표회
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• pp.41-44
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• 2004

Recently, in the case of domestic, for all that the deterioration environment about the carbonation of reinforced concrete structures is accelerated, systematic diagnosis and researches are not completed. And the selection techniques of repair material and method used under the situation that the indicator and the performance evaluation method are nor established are dependant on existing experience. Therefore, the purpose of this study is intend to present fundamental data for the reasonable selection of repair material and method. durability design and longevity on the deteriorated reinforced concrete structures, through computing the carbonation depth and velocity coefficient by accelerating carbonation test under various accelerating conditions and investigating the application of carbonation evaluation method. The results of this study are as follow; The resistances to carbonation are increased when the W/C ratio if lower and the treatment of surface coating is executed. And the carbonation depth and velocity coefficient according to accelerating carbonation test conditions are increased when the conditions of temperature, relative humidity and $CO_2$density are higher individually.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 춘계학술발표대회 논문집
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• pp.269-272
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• 2005

Nondestructive damage sensing and load transferring mechanism of Ni nanowire strands and multi-wall carbon nanotube (MWCNT)/epoxy composites were investigated using electro-micromechanical techniques. MWCNT composite was especially prepared for high volume contents, 50 vol % of reinforcement. Electro-micromechanical techniques were applied to measure apparent modulus and contact resistance of Ni nanocomposites with their alignment and different diameters, and adding contents. Applied cyclic load affected on apparent modulus and electrical properties on nanocomposites due to various inherent properties of each CNMs. Contact resistivity on humidity sensing was a good indicator for monitoring as for multifunctional applications. Further study on actuation as well as sensing will be investigated for the following work continuously.

• KIEAE Journal
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• 제17권4호
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• pp.89-94
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• 2017

Purpose: Condensation in walk-in closets attached to apartment bathroom has been known as an emerging issue that may threat occupants' comfort and health. Despite a number of design guidelines and enforcements to prevent condensation, condensation issues may still occur depending on various cases and scenarios. We aim to identify what condensation scenarios may lead to walk-in closet condensation and/or worse the existing condensation issues. Method: First we choose an actual walk-in closet of an apartment that suffers from sporadic condensation and resulting mold and mildew. Then we observe its relative humidity and temperature after the bathroom is used, in which excessive vapor is thought to be transported to the walk-in closet. We analyze Temperature Difference Ratio - a domestic indicator of condensation occurrence, and dew point temperature to compare it with surface temperature using 2D heat transfer simulation upon various condensation scenarios. Result: TDR of the test walk-in closet turns out be OK despite mold and mildew actually occurring. Hot water pipe installed in the floor would greatly reduce condensation. If hot water pipe in the upper floor, however, is not used, or hot water pipe of the closet is turned off during swing seasons, it is expected that condensations may still occur.