• Resources Recycling
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• v.9 no.3
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• pp.13-21
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• 2000

This study describes to analyze the heat transfer characteristics of waste solvent recovery system using a double pipe heat exchanger heating solvent by the hot oil. The solvent recovery system consists of the feeding pump, the double pipe heat exchanger, the vacuum spray chamber, and the condenser. A double pipe heat exchanger consists of the first section to conduct the heating of solvent to the thermal saturated point and the second section to evaporate the saturated solvent. The heat transfer area for vaporization of water, benzene and alkylbenzene was predicted by the heat balance modelling and experimentally measured from the temperature distribution as a function of solvent flow rate and heating temperature. The required heat transfer area for vaporization was increased with increasing solvent flow rates and with decreasing heating temperatures due to decreased quantity of transferred heat per the unit area. Theoretical modelling of the heat transfer area for solvents vaporization in the pipe showed good agreement with experimental results. Results showed to be suitable for the waste solvent recovery using a double pipe heat exchanger.

• Journal of Energy Engineering
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• v.23 no.2
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• pp.175-182
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• 2014

The use of solar energy among renewable energy tends to increase because of infinity and cleanness of resources. Even though the consumption rate of solar energy in our country is still low, however, in recent years, the research for solar energy have been widely conducted due to policy support of government. This study was performed to make the system of performance test for solar collector and to investigate thermal efficiency for solar collector with thermosyphon tube-type. As a result, in case of indoors measurement using halogen lamp, thermal efficiency for solar collector with thermosyphon tube-type was increased about 15~22% after 120 minutes compared with that of solar collector with double evacuated tube-type. In addition, in case of outdoors measurement, thermal efficiency of thermosyphon tube-type was showed maximum about 46% higher than double evacuated tube-type.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10b
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• pp.190-192
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• 1999

한국어는 용언이 의미적 제약을 통해 문장을 지배하는 SOV 구조의 언어이다. 또한, 조사나 어미와 같은 기능어의 발달은 물론 관형절은 내포하는 문장이 주류를 이룬다. 따라서 한국어의 구문분석은 부착에 따른 많은 구문 모호성이 발생하게 된다. 본 논문에서는 조건단일화 기반의 CFG문법을 기술하고 문형을 구문 제약으로 하여 구문모호성을 해결하는 방안을 제시한다. 문형은 한국어의 특성을 용언의 하위범주화에 맞게 재분류한 문장의 구조적 유형을 말한다. 본 논문에서 제안하는 문형은 동사와 형용사를 구분하여 39가지로 설정하였다. 이런 문형 정보를 이용하여 관형형 어미를 갖는 용언이 최대의 정보를 가지도록 함으로써 관형절에서 발생하는 부사 및 체언구 부착의 문제가 해결된다. 또한 문형은 이중주어나 이중 목적어 문장을 처리할 수가 있어 한국어에서 발생하는 많은 구문모호성을 해결할 수 있다.

• Journal of Biosystems Engineering
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• v.14 no.1
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• pp.24-32
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• 1989

고밀도(高密度)의 열(熱)에너지를 저장(貯藏)하기 위(爲)한 잠열축열장치를 설계(設計), 제작(製作), 작동(作動)하는 경우 잠열축열장치의 사용목적(使用目的)에 적합(適合)한 최적설계(最適設計)와 그 효율적(效率的)인 이용(利用)을 위(爲)해서는 그 부열특성(傅熱特性)이 규명(糾明)되어야 한다. 본(本) 연구(硏究)에서는 실용화(實用化)에 필요(必要)한 이중관형(二重管形) 잠열축열장치의 방열과정(放熱過程)에서의 부열특성(傅熱特性)을 이차원적(二次元的)으로 실험(實驗) 분석(分析)하였으며, 시간변화(時間變化)에 따른 잠열재의 온도변화(溫度變化)와 응고율(凝固率)이 실험분석치(實驗分析値)와 이론분석치(理論分析値)에 있어서 잘 일치하였다. 한편 응고율(凝固率), 방열율(放熱率), 물의 온도변화(溫度變化)에 대(對)한 분석(分析)을 하였다.

• Journal of Energy Engineering
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• v.21 no.4
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• pp.356-361
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• 2012

Recently, even though the researches on renewable energy like geothermal, wind, solar energy have been performed widely, its use-rate in total energy is still low. This study was carried out to investigate the performance of hybrid heating system, which consisted of solar collector of thermosyphon tube type and X-L pipe boiler. Especially, new type of solar collector was tried and compared with double tube type and, futhermore, performance and safety on X-L pipe boiler were investigated. As the results, efficiency of solar collector of thermosyphon tube type was higher 20.7% than that of double tube type, mainly due to its structural characteristics. It was also confirmed that temperature of special heat medium used X-L pipe boiler rose up about 20% rapidly in comparison with that of pure water.

• Solar Energy
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• v.10 no.1
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• pp.38-46
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• 1990

For the optimal design and the efficient operation of the double pipe type latent heat storage equipment, the effect of the parameters of the system were analysed. The statistical analysis showed that the theoretical and the experimental results of the volume change rate and the temperature variations were well agreed. Therefore, this theoretical model is reasonable to analyze two dimensional moving boundary problems. In the analysis of the effects of the parameters, the heat extraction fraction and the water outlet temperature of the system as function of the time were analysed depending on the initial temperature of PCM, water inlet temperature, water mass flow rate and the dimension of the inner tube.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.21-26
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• 2017

In this study, performance tests were conducted to investigate the applicability of a double-tube heat recovery ventilation system. Paper, aluminum, polymer, were investigated as materials for the inner tube using the same exhaust-air volume. In all cases, the temperature exchange efficiency of the aluminum tube was the highest, while the paper tube showed similar results to those of the polymer tube. This probably resulted from the differences in thermal conductivity and thicknesses of the materials. The humidity exchange efficiency was the highest for the paper tubes in all cases, while the aluminum tubes and polymer tubes showed similar results. The total heat exchange efficiency, which includes the values of humidity exchange and temperature exchange, was highest in the case of the paper tube, and the aluminum tube and the polymer tube showed similar results. In the case of the paper tube, sensible heat and latent heat exchange occur at the same time, and the coefficient of energy of the aluminum tube and polymer tube are large values, when to be compared with only applicably sensible heat exchange coefficient of the aluminum tube and the polymer tube of total heat exchange efficiency value. The results of this study could be applied to the design of a ventilation system.

• Annual Conference on Human and Language Technology
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• 2003.10d
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• pp.158-162
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• 2003

이중주어 문장이란 하나의 용언이 두 개의 주격조사를 취하는 경우를 말한다. 이러한 이중주어 현상은 영어권에서는 없는 현상으로, 한국어 분석 측면에서 어려움을 야기할 뿐 아니라, 자동 번역 측면에서도 반드시 고려되어야 하는 현상이다. 그러나 이중주어의 분석에 대한 기존 연구는 국어학 분야에서만 진행되었을 뿐 자연어 처리분야에서는 다루어진 적이 없다. 본 논문에서는 이중주어 현상에 대한 분석을 통해, 이중주어 현상이 한국어 문장에서 빈번히 발생하는 현상이며, 기존의 ‘명시-격조사-용언’으로 구성되는 공기정보만으로는 이중주어 문장을 올바로 분석할 수 없음을 보인다. 이를 해결하기 위해 본 논문에서는 이중주어의 특성을 파악하고, 이들 특성에 맞게 ‘명사-격조사-용어’ 공기정보뿐 아니라 명사들 간의 공기정보 및 관형형 용언과 명사 공기정보, 그리고 주격조사의 교체를 통한 이중주어 분석 방법을 제안한다.

• Resources Recycling
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• v.9 no.4
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• pp.28-36
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• 2000

This study describes to analyze the characteristics for separation and recovery of both the dried particles and the purified solvent from the waste solvent through the vaporization process by the continuous and instantaneous vacuum drying system. The vacuum drying system for the waste solvents recovery consists of a feeding pump, a double pipe heat exchanger, a vacuum spray chamber, and a condenser. The vacuum drying system heats the waste solvent to the vapor in the double pipe heat exchanger and the expanded vapor is sprayed at the end of the tube. The vaporized solvent in the condenser are recovered. The particles in the waste solvent are separated and dried from the vapor in the vacuum spray chamber. Performance evaluation of the vacuum drying system was conducted using the mixture of the dried pigment particles and benzene or alkylbenzene as test samples. For the mixture of 10 wt% pigment particles an 90% benzene, the recovery efficiency of benzene was 88% with the purity of 99% and the recovery efficiency of dried particles was 94% with the moisture of 1.1 wt%. The size of pigment particles was decreased from $6.5\mu\textrm{m}$ to $5.6\mu\textrm{m}$ in diameter due to high speed spraying and dispersion in the vacuum drying system during drying process. Therefore, the vacuum drying system showed to be an effective method for separating particles and solvent in the waste solvent.

• Proceedings of the SAREK Conference
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• 2003.07a
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• pp.229-229
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• 2003