• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.778-782
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• 1997

Effects of different water potential on the growth and aerenchyma development of Adlay(Coix lacryma-jobi L. var. mayuen) were studied under every 3 days intermittent irrigation as a control at different growth stages, flooded pot condition and drought. Adlay could not germinate in the anaerobic soil conditions with excessive moisture while it wasn't inflicted with moisture damage after sprouting. Sprouted adlay can grow under flooded soil moisture condition because it's root has orthostichy cell, ventilating structure and cortex. Proping or ventilating roots were generated from adlay grown under flooded pots. Drought damage inflicted at the heading stage was the most severe.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.10
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• pp.696-701
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• 2008

From Feb. 2006, the ventilating systems with air exchange rate of over 0.7times/hour are installed at the apartment houses (over 100 units). Installation cost and maintenance cost are very important factors for ventilating system because consumers have to pay the expenses of that system. Especially small apartment needs more considerations because small apartment is comparatively the economically weak part. The purpose of this study is to the performance evaluation of the hybrid ventilation system for small apartment houses. Hybrid system 1 consists of natural ventilation system and duct type exhaust diffusers. Hybrid system 2 has natural ventilation system and toilet exhaust system with static pressure fan. Infiltration of test apartment houses with ventilation system is under 0.1 times/hour. Mean air age of hybrid system 1 is 1.52 hours and hybrid system 2 is 1.42 hours. Mean ventilation effectiveness of hybrid system 2(93%) is higher than that of hybrid system 1(81%).

• Proceedings of the Korean Society of Computer Information Conference
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• 2024.01a
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• pp.47-48
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• 2024

Heating, Ventilating, and Air Conditioning(HVAC) 시스템은 난방(Heating), 환기(Ventilating), 공기조화(Air Conditioning)를 제공하는 공조시스템으로, 실내 환경의 온도, 습도 조절 및 지속적인 순환 및 여과를 통해 실내 공기 질을 개선한다. 이러한 HVAC 시스템에 이상이 생기는 경우 공기 여과율이 낮아지며, COVID-19와 같은 법정 감염병 예방에 취약해진다. 또한 장비의 과부하를 유발하여, 시스템의 효율성 저하 및 에너지 낭비를 불러올 수 있다. 따라서 본 논문에서는 HVAC 시스템의 이상 탐지 및 조기 조치를 위한 Transformer 기반 이상 탐지 기법의 적용을 제안한다. Transformer는 기존 시계열 데이터 처리를 위한 기법인 Recurrent Neural Network(RNN)기반 모델의 구조적 한계점을 극복함에 따라 Long Term Dependency 문제를 해결하고, 병렬처리를 통해 효율적인 Feature 추출이 가능하다. Transformer 모델이 HVAC 시스템의 이상 탐지에서 RNN 기반의 비교군 모델보다 약 1.31%의 향상을 보이며, Transformer 모델을 통한 HVAC의 이상 탐지에 효율적임을 확인하였다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.2
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• pp.161-168
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• 2011

The heating, ventilating, air conditioning (HVAC) system is a very important part of an automotive vehicle: it controls the microclimate inside the passenger's compartment and removes the frost or mist that is produced in cold/rainy weather. In this study, the numerical analysis of the defrost duct in an HVAC system and the de-icing pattern is carried out using commercial CFX-code. The mass flow distribution and flow structure at the outlet of the defrost duct satisfied the duct design specification. For analyzing the de-icing pattern, additional grid generation of solid domain of ice and glass is pre-defined for conductive heat transfer. The flow structure near the windshield, streakline, and temperature fields clearly indicate that the de-icing capacity of the given defrost duct configuration is excellent and that it can be operated in a stable manner. In this paper, the unsteady changes in temperature, water volume fraction, and static enthalpy at four monitoring points are discussed.

• Science of Emotion and Sensibility
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• v.23 no.4
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• pp.33-40
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• 2020

As the number of automobile registrations increases and luxury expectations grow, consumers are increasingly interested in indoor environment of vehicles. Therefore, manufacturers have an increasing interest in improving the indoor comfort as well as automobile performance. Research on indoor automobile comfort can help manufacturers increase driver satisfaction and reduce driver stress and discomfort, thereby reducing the risk of traffic accidents. Using electroencephalogram (EEG) measurements, we investigated the change in comfort and comfortable temperature according to the ventilating seat temperature change for both men and women. Results showed that the sensation of comfort was statistically significantly higher at 25℃ than at 28℃. Secondly, there was no statistically significant difference in temperature-based comfort feeling between male and female subjects. In the future, if the correlation between the driver's comfort feeling and the change in ventilating seat temperature is analyzed, it is possible to reduce traffic accidents caused by human error and reduce the electric energy consumption of the automobile.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1990.10a
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• pp.57-62
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• 1990

This paper describes the development and testing of a degitial controller for heat-ing ventilating and air-conditioning system. The controller uses properational-integral control action and self tunes to provide the Zigeler-Nichols when given a step input. The algorithm has been simulated fas static pressure.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2001.11a
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• pp.96-101
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• 2001

동계의 노지 및 무가온 시설재배시에 상추와 시금치 등의 엽채류 재배는 생육이 거의 정지되는 온도에서 재배되고 있다. 이와 같은 저온기의 불량환경조건을 개선하기 위하어 저온성 엽채류에 직접 피복할 수 있는 통기성 피복자재가 개발되어 생육촉진이나 품질향상을 위한 연구가 지속되어 왔으나 피복방법의 개선에 관한 연구는 아직도 미흡한 실정이다. (중략)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.554-560
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• 1998

Acoustic performance of the absorptive mufflers used in air-conditioning and ventilating ducts, gas turbines, industrial fans influenced by the design parameters such as the length of mufflers, lining thickness, properties of the acoustic lining, and so forth. So we predicted the acoustic performance according to the design parameters. For the analysis, we assumed the radial propagation constant is locally reacted to the acoustic lining, and analyzed the acoustic performance based on the plane wave theory by using four-pole parameters.

• Proceedings of the SAREK Conference
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• 2003.07a
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• pp.194-194
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• 2003

• Journal of Biosystems Engineering
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• v.34 no.1
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• pp.63-68
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• 2009

This study was carried out to determine necessary conditions for optimal ventilation of small windowless piglet house (5.2 (W) ${\times}$ 12.3 (L) ${\times}$ 2.3 (H) m) with negative tunnel ventilating system using CFD (Computational Fluid Dynamics) simulation. The weaning piglet house for this experiment was consisted of 4 rooms (520 (W) ${\times}$ 300 (L) cm), 3 fences (70 (H) cm), 1 air inlet (350 (W) ${\times}$ 2 (H) cm) and 1 exhaust fan (50 (D) cm), and simulated using CFD code, FLUENT. The simulation results for the original weaning piglet house showed ununiform ventilation for each room. Therefore, to uniformly ventilate all rooms, the heights of the air inlet and first fence were modified to 3 cm and 100 cm, respectively. The simulation result f3r the modified weaning piglet house showed uniform ventilation for all rooms and the optimum air inlet velocity of 1.4 m/s.