• Journal of Korea Water Resources Association
• /
• v.40 no.7
• /
• pp.571-583
• /
• 2007

The effects of climatic changes owing to urbanization, geographical and topographical conditions on Penman-Monteith reference evapotranspiration, and energy and aerodynamic terms of Penman-Monteith reference evapotranspiration have been studied. In this study, 56 climatological stations including the Seoul metropolis in South Korea have been selected, and the area of study site was set at $314\;km^2$. The climatological station is centrally located In the study area with a 10 km radius. The geographical and topographical characteristics of these sites were examined using GIS analysis. Land use status of the study area was also examined to estimate the extent of urbanization. The study results indicated that the variation of reference evapotranspiration rate is closely related to urbanization in most climatological stations. The level of change in reference evapotranspiration was higher in areas with higher urbanization rates. The change in reference evapotranspiration appears to be caused by temperature rises following heat island phenomena due to urbanization, and by the decrease in humidity, wind speed and sunshine duration due to the Increase in residential areas in urban districts. Especially, the humidity decrease causes a significant decrease in evapotranspiration rate. The study results showed that climatic change due to urbanization and proximity to the coast had the greatest effect on reference evapotranspiration.

• Journal of Korean Ophthalmic Optics Society
• /
• v.17 no.2
• /
• pp.215-222
• /
• 2012

Purpose: This study was performed to investigate the influence of indoor air qualities of an office environment on dry eye syndrome for wearing contact lens and non-wearing contact lens. Methods: To study the effects of indoor air qualities on dry eye syndrome for seventy-one subjects, $CO_2$, temperature, humidity, TSP, PM10, HCHO were measured. Each subject was tested by a McMonnie's dry eye syndrome questionnaire, a Schirmer Tear Test-I (S.T.T-I), a Schirmer Tear Test-II with anesthetics (S.T.T-II), and Tear film break-up time (T.B.U.T) in the their offices. Results: There was significant relation between the indoor air quality and dry eye syndrome for wearing contact lens and non-wearing when TSP was over $200{\mu}g/m^3$, PM10 was higher than $86.7{\mu}g/m^3$ and Formaldehyde was over $0.4{\sim}1.0{\mu}g/m^3$. However, there was no significant effect on dry eye syndrome with $CO_2$ (p=.0146), temperature (p=0.074) and humidity (p=0.053). Conclusions: It was indicated that $CO_2$, temperature and humidity were no effect on dry eye syndrome in the office environment. However TSP, PM10, formaldehyde, and wearing contact lens were effect on dry eye syndrome. Therefore, the entire management of wearing contact lens and the individual evaluation of the indoor air quality are required.

• Korean Journal of Food Science and Technology
• /
• v.13 no.4
• /
• pp.314-318
• /
• 1981

In order to improve the storage stability of spray and freeze dried red ginseng extract powder packed in a bottle, the water vapor permeability of Al-foil laminate paper used for cap closure and shelf life of those products on various storage temperatures and relative humidities were investigated. The thickness of the laminate paper was $93{\pm}3\:{\mu}m$ and its physical properties were equal to standard of ASTM (B-377-66) The absorption rate of the freeze dried powder was 2-6 times greater than that of the spray dried powder at $37^{\circ}C$. Therefore it was considered that the laminate could be used for cap closures for the spray dried powder but unsuitable for the freeze dried powder. The shelf life of the spray dried powder was longer than that of the freeze-dried powder at $37^{\circ}C$.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.37 no.2
• /
• pp.199-204
• /
• 2013

Owing to the global energy crisis, studies have strongly focused on realizing energy savings through vehicle weight reduction using light metal alloys or polymer composites. Polymer composites afford many advantages including enabling the fabrication of complex shapes by injection molding, and glass and carbon fibers offer improved mechanical properties. However, the high temperature in an engine room and the high humidity during the rainy season can degrade the mechanical properties of the polymer. In this study, the mechanical properties of injection-molded glass-fiber-reinforced polymer were assessed at a temperature of $85^{\circ}C$ and the maximum moisture absorption conditions. The result showed a 23% reduction in the maximum tensile strength under high temperature, 30% reduction under maximum moisture absorption, and 70% reduction under both heat and moisture conditions. For material selection during the design process, the effects of high temperature and high humidity should be considered.

• Journal of Korea Society of Industrial Information Systems
• /
• v.21 no.6
• /
• pp.71-80
• /
• 2016

Along with the increase in the standard of living, the interest and awareness level of the public about environmental issues have also gradually increased. Recently, time spent on indoor activities have increased and the need for awareness and demand on methods in improving the quality of an indoor environment has been recognized. The purpose of this study is to sense the environment information through real-time monitoring of the room environment by using the IoT based technology and to maintain and improve the indoor environment to an appropriate level through the developed interlocking controller device. This provides an automatic control system in improving the indoor environment at home and other small areas like general offices in place of the traditional passive interior environmental improvement actions or large-scale facility control system. A status analysis with the relative reference values of the air quality and CO2, temperature and humidity and illumination and noise was applied through transmitting a control signal to automatic control module in accordance with the nine indoor environment standards set to improve the indoor environment.

• Food Science and Preservation
• /
• v.6 no.2
• /
• pp.143-147
• /
• 1999

Onions were subject to quality evaluation from the physiological and physicochemical points of view during storage under different conditions, which were low temperature (2-4$^{\circ}C$, 80% RH), pit temperature (3-15$^{\circ}C$, 75-85% RH), room temperature (10-23$^{\circ}C$, 75-98% RH) and ambient temperature (2-25$^{\circ}C$, 62-72% RH). Sprouting were dereloped from the 11th month of storage in low temperature. Rotting was quickly occurred from the 7th month of storage excepting onions in room temperature. Low temperature storage showed the least weight change. Moisture content increased with the lapse of storage time at both low temperature and pit temperature storage conditions, but decreased with the lapse of storage time at room and ambient temperature conditions. Total and reducing sugars decreased with the storage time, while vitamin increased in stored onions at low temperature.

• Journal of KIISE:Computing Practices and Letters
• /
• v.16 no.8
• /
• pp.842-852
• /
• 2010

RFID applications use tags to identify objects, but recent applications tend to include diverse sensor devices such as light, temperature, and humidity sensors as well. RFID tag information is usually processed via the event driven model. However sensor devices are usually accessed via the functional call model. Therefore application developers have to deal with mixed data access models and device dependent interface functions. In this paper, we propose a sensor reader emulator that provides a consistent access interface to sensor devices regardless of the types of devices. SRE provides a more efficient way of developing RFID applications by providing a single application programmer's view to RFID tags and sensor devices. In applications where tags are fixed to a place, SRE can replace expensive sensor tags and sensor readers with inexpensive sensor devices reducing the total cost while providing the same functionality.

• 한국방재학회:학술대회논문집
• /
• 2011.02a
• /
• pp.219-219
• /
• 2011

순 장파복사량은 지표면으로 입사되는 하강 장파복사량(Downward Longwave Radiation, $R_{ld}$)과 지표면에서 반사되는 상승 장파복사량(Upward Longwave Radiation, $R_{lu}$)의 차이로 정의되는데 이는 에너지 수지 및 농업기상 연구의 중요한 주제 중 하나로서 다루어져 온 순복사량의 중요한 요소이다. 일반적으로 $R_{lu}$의 경우 지표면 온도와 방사율(emissivity)를 이용하여 산출되므로 정확히 추정이 가능하나, $R_{ld}$의 경우 대기 최상층에서 관측되는 방사량과 지표면 근처의 방사량을 함께 고려해야 하므로 실측이 어렵다. $R_{ld}$는 야간 복사계(pyrgeometer)를 이용하여 직접적으로 측정할 수 있지만 관측기기 자체가 구비되어있는 관측소가 적어 매우 드물게 이용된다. 또한 단파 복사 에너지 측정 기기에 비해 비용이 많이들고 종종 관측값이 큰 오차를 가지고 있기 때문에 실무에 적용하기 힘든 단점이 있다. 따라서 기상 관측소에서 얻어지는 증기압과 온도 관측치를 물리식, 경험식 등에 적용하여 산정하게 된다. 현재는 $R_{ld}$의 추정은 관측된 방사량간의 관계를 나타내는 경험식을 기반으로 지표면 근처의 대기 온도와 습도를 이용하여 산출하는 방법이 널리 사용되고 있다. 본 연구에서는 증발산 산정 알고리즘 개발의 시발점으로써 $R_{ld}$를 먼저 구하고 $R_{lu}$를 구하였다. 신뢰성 높은 방법을 이용하여 $R_{ld}$를 구하게 되면 정확도 높은 $R_N$을 구하는 데 기여할 수 있으며, 궁극적으로 보다 정확한 증발산을 산정할 수 있게 된다. $R_{ld}$는 일반적으로 clear sky 조건 하에서의 복사 에너지 플럭스($R_{ldc}$)를 구한 후 구름의 양에 따라 보정한다. 하강 장파복사량의 경우 널리 사용되는 공식 중 하나인 Brutsaert의 공식을 사용하였다. 광릉, 해남에 위치한 플럭스 타워지점에서 실측된 기온과 실제 수증기압을 입력인자로 사용하여 지점별 $R_{ldc}$를 먼저 구하고 Moderate Resolution Imaging Spectroradiometer(MODIS) 영상자료를 이용하여 검증한 뒤 최종적으로 남한지역을 대상으로 순 장파복사량 지도를 작성하였다. 이를 위해 MODIS 07 대기 프로파일 산출물(Atmospheric Profile Product)중 기온 및 이슬점온도를 추출하여 산정식의 입력자료로서 사용하였다. 상승 장파복사량의 경우 MODIS 11 지표면 온도 산출물(Land Surface Temperature product)를 이용하여 산정하였다. 이는 남한 지역의 증발산량 추정 및 에너지 수지 연구를 위한 중요한 기본 자료로서 유용하게 사용될 수 있으리라 사료된다.

• Journal of Korea Multimedia Society
• /
• v.13 no.11
• /
• pp.1728-1738
• /
• 2010

Pyeon-gyeong, similar to Chinese Bianqing, is a Korean traditional lithophone with multiple stone chimes. Due to the temperature- and humidity-insensitive characteristics of its material, pumice stone, the instrument provides highly stable pitch and therefore has played a key role in Korean traditional court music. By reason of having absolute pitch, it is an important part of the research on the standard pitch and scale system of korean traditional music, but as an instrument, the study on the sound characteristics and worth is not making satisfactory progress, to date. This research is an analysis paper for physical modeling synthesis of pyeongyeong. Through this study, we will determine the original characteristics of the timbre of pyeongyeong as a unique korean traditional percussion, and investigate these characteristics objectively, based on the music acoustics by scientific analysis. Furthermore, this study will be used as an important basic material for physical modeling synthesis of pyeongyeong, and also make a huge contribution to the cultural applicability by the vitalization of graft onto the various artistic creation field, through the comprehension of the timbre of pyeongyeong as an instrument.

• Journal of the Korean Society for Railway
• /
• v.13 no.1
• /
• pp.37-43
• /
• 2010

Catenary (Overhead Contact Lines) and Pantograph are used to transmit electrical energy to electric railways. An Arc occurs by unstable contact between catenary and pantograph during electric railways operation, which causes malfunctioning or even an accident. Therefore, to prevent a arc or electric contact loss are required arc detection systems with catenary maintenance capability. This paper describes developing of catenary arc detection system using photo detector in order to detect arc incidence in a indirect way. This developed system can also achieve Video-recordings and environmental conditions such as wire voltage/current, pantograph height, speed, position of electric railways, and temperature/humidity. This system have been evaluated at the section that bounds for dongdaegu from seoul. From the experimental results, the occurrence of arc and intensity of arc are mainly effected by wire voltage/current, pantograph height and speed of electric railways.