• Fire Science and Engineering
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• v.17 no.4
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• pp.98-104
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• 2003

Smoke control in il space 10 m${\times}$3 m floor and 5.4 m high around the stairway of a subway station platform was simulated by using FDS to investigate problems of smoke control in Daegue subway stations. Distributions of temperature and smoke particles, and variation of the number of particles with time for a 200 ㎾ polyurethane fire were compared. It was shown that the purge system fails to remove smoke efficiently and that the extraction system has the highest perfor-mance among the three smoke control systems for the given situations. Simply switching the purge system into extraction mode might improve much the smoke removal performance.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.12
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• pp.633-638
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• 2015

This study evaluates the capacity of night purging in office buildings to reduce the cooling load. RTS-SAREK is used to estimate the performance of night purging on the steady state. To overcome steady state RTS program limitations, we added unsteady heat transfer equations. When the ACH (Air Change per Hour) increases, the wall temperature decreases in both the steady and unsteady states. The unsteady heat transfer rate is different from the steady transfer rate, which validates the unsteady calculation. When ACH is low, the heat transfer rate increases continuously with time. When ACH becomes higher, the heat transfer rate increases and decreases with time. When ACH is quite high, there exists a large difference in the heat transfer rate between the steady and unsteady calculations, which emphasizes the importance of the unsteady calculation.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.196.1-196.1
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• 2013

반도체의 device design rule이 shrink 됨에 따라 공정이 난이도가 높아지고 이에 따른 관리가 어려워지고 있다. 특히 미세 particle에 대한 제어의 필요성은 보다 커졌다. 진공 chamber 발생하는 미세 particle의 주요 원인으로는 공정 중 발생한 polymer, chamber 내 부품의 식각 및 스퍼터링에 의한 부산물 등이 있다. Plasma 공정 도중 발생한 particle은 plasma 내 전자에 의해 대전되어 음의 전하량을 가지게 된다. 음의 전하량을 가진 particle은 plasma와 wafer의 경계면에서 형성되는 sheath 때문에 wafer에 도달하지 못하고 plasma 내에 부유하게 된다. 이러한 particle은 plasma가 꺼지게 되면 sheath가 사라지면서 wafer에 도달하게 되고 wafer의 오염을 유발하게 되고 생산 수율을 저하시키는 요인이 된다. 이러한 이유로 최근 plasma 공정에서는 공정 중 발생하는 부유성 particle에 대한 관리가 중요해졌다. 이를 관리하기 위해 plasma를 끄기 전 부유성 particle을 제거하는 방안을 고안하고 평가를 진행하였다. 공정이 끝나고 plasma가 꺼지기 전 plasma를 유지하여 부유성 particle이 wafer에 도달하지 못하는 상태에서 gas purge를 실시한다. 이러한 과정 후 plasma를 끄게 되면 부유성 particle이 wafer에 도달하는 것을 감소시키게 된다. 이번 평가를 통해 부유성 particle에 대해서 대략 20%의 감소 효과를 볼 수 있었다. 이를 토대로 향후 조건 최적화 후 적용 시 particle 감소뿐 만 아니라 수율 향상에도 기여할 수 있을 것이라 기대된다.

• New & Renewable Energy
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• v.5 no.4
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• pp.46-51
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• 2009

The purpose of this study is to investigate selective adsorption of $CO_2$ from LFG (Landfill gas) by using commercialized NaX-type zeolite adsorbent under the ambient temperature and pressure. The experiment of $CO_2$ adsorption was carried out by using simulated LFG. The $CO_2$ adsorption capacity and separation efficiency of NaX-type adsorbent were investigated by analyzing gas flow rate and gas composition at inlet and outlet of the adsorption reactor. The adsorbed $CO_2$ were desorbed under decompression condition which 0.5 Torr or by air purge. Through the result to use simulated LFG, when the method of VSA was used, 73.2~75.3 mg of $CO_2$ was adsorbed per 1 g commercial adsorbent, when the method of air purge was used, 78.4~83.2 mg of $CO_2$ was adsorbed per 1 g of commercial adsorbent.

• Korean Journal of Metals and Materials
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• v.48 no.5
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• pp.449-455
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• 2010

To enhance the efficiency of dye sensitized solar cells, we proposed crystalline anatase-$TiO_{2}$ by using a low temperature process ($150^{\circ}C{\sim}250^{\circ}C$). We successfully fabricated 30 nm-$TiO_{2}$ at a fixed atomic layer deposition condition of 1.0 sec of TDMAT pulse, 20 sec of TDMAT purge, 0.5 sec of H$_{2}$O pulse, and 20 sec of H$_{2}$O purge. In order to examine the microstructure, phase, and band-gap of the TiO$_{2}$ respectively, we employed a Nano-Spec, transmission electron microscope, high resolution XRD, Auger electron spectroscopy, scanning probe microscope, and UV-VIS-NIR. We were able to fabricate a crystalline anatase-phase of 30 nm-TiO$_{2}$ successfully at temperatures above $180^{\circ}C$. Our results showed that our proposed low temperature ALD process (below $200^{\circ}C$) might be applicable to glass and flexible polymer substrates.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.6
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• pp.819-826
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• 2022

Fuel cell systems are being supplied to households and buildings to reduce greenhouse gases. The fuel cell systems have problems of high cost and slow startup due to fuel processors. Greenhouse gas reduction of the fuel cell systems is also limited by using natural gas. The problems can be solved by using a hydrogen generator consisting of a reformer and pressure swing adsorption (PSA). However, part load operation of the hydrogen generator is required depending on the hydrogen consumption. In this paper, PSA operation strategies are investigated for part load of the hydrogen generator. Adsorption and purge time were changed in the range of part load ratio between from 0.5 to 1.0. As adsorption time increased, hydrogen recovery increased from 29.09% to 48.34% at 0.5 of part load ratio. Hydrogen recovery and hydrogen purity were also improved by increasing adsorption and purge time. However, hydrogen recovery dramatically decreased to 35.01% at 0.5 of part load ratio.

• Herbal Formula Science
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• v.16 no.1
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• pp.29-38
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• 2008

Background and Objectives : There are four kinds of formulas for invigorating the kidney to cure its asthenic syndrome based on the types of preparation formulas : Boshintang, Boshinhwan, Boshinsan, and Boshingaeng. There are 16 kinds of Boshintang, 28 kinds of Boshinhwan, 3 kinds of Boshinsan, and one kind of Boshingaeng. Combination of herbal medicines, carried out in formulas for invigorating the kidney, consists of various kinds depending on medical scientists' personal experience in medical treatment without any general principles, which makes it difficult to apply it to clinical use. The objectives of this study lie in theoretical establishment of Boshintang for curing the asthenic syndrome of kidney through analyzing the component medicines and combination principles of Hyeongok's Boshintang, and furthermore, maximizing the clinical use of Boshintang. Methods : This study analyzed the component medicines and combination principles of Hyeongok's Boshintang based on the theory for properties and tastes of herbal medicines from the ${\ulcorner}$Yellow Emperor's Canon of Internal Medicine${\lrcorner}$ , the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, dispatcher herbal medicine, and the five elements doctrine. Hyeongok's Boshintang is an even prescription, composed of 6 kinds of ingredients : No.1 Fructus Lycii (3don;11.25g), No.2 Radix Polygoni Multiflori (1don:3.75g), No.3 Sarcucarpium Corni (1don), No.4 Fructus Schisandrae (1don), No.5 Rhizoma Anemarrhenae (5poon: 1.875g), and No.6 Cortex Phellodendri (5poon) Results : There are three methods for curing the asthenic syndrome of kidney according to the five elements doctrine : invigorating the kidney, invigorating the lung and purging the spleen. First, if you suffer from the asthenic syndrome of the kidney, you need to invigorate your kidney. There are two available methods, including taste and property invigoration according to the theory for properties and tastes of herbal medicines. They each imply the bitter taste and the cold property invigorate the kidney. In the case of taste invigoration, two herbal medicines with bitter taste, Fructus Lycii and Radix Polygoni Multiflori, are combined into the principal and assistant herbal medicine, respectively. For property invigoration, two herbal medicines with the cold property, Rhizoma Anemarrhenae and Cortex Phellodendri, are combined into adjuvant herbal medicines. Secondly, if you suffer from the asthenic syndrome of the kidney, you need to invigorate your lung which is mother in the mother-child relationship in inter-promotion among the five elements. There are two methods to invigorate the lung, including taste and property invigoration according to the theory for properties and tastes of herbal medicines. They each mean the sour taste and the cool property invigorate the lung. Therefore, it is important to use sour herbal medicines for taste invigoration and cool ones for property invigoration. Both bitter and cool herbal medicines, Rhizoma Anemarrhenae and Cortex Phellodendri, are combined into adjuvant herbal medicines. Lastly, if you suffer from the asthenic syndrome of the kidney, you need to purge your spleen which is an element being surpassed in the relationship between the elements surpassed and ones not surpassed in inter-restraint among the five elements. There are two methods to purge the spleen, which include taste and property purgation according to the theory for properties and tastes of herbal medicines. Taste purgation means to purge the spleen with bitter taste and property purgation to purge the spleen with cool property. Therefore, it is important to use bitter herbal medicines for taste purgation and cool ones for property purgation. Both bitter and cool herbal medicines, Rhizome Anemarrhenae and Cortex Phellodendri. were combined to purge the spleen and invigorate the kidney. In addition, Rhizome Anemarrhenae and Cortex Phellodendri are combined as dispatcher herbal medicine, reinforcing the kidney energy. Conclusions : First, to cure the asthenic syndrome of the kidney, the methods of invigorating the kidney and the lung, and purging the spleen should be used according to the five elements doctrine. Secondly, herbal medicines appropriate for those treatment methods should be chosen according to the theory for properties and tastes of herbal medicine and thirdly, the combination of those herbal medicines should be carried out according to the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, dispatcher herbal medicine. As a good example, Hyeongok's Boshintang is combined according to the above theories. In conclusion, this formula was created by applying to the theory for properties and tastes of herbal medicines.

• Journal of the Korean Vacuum Society
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• v.17 no.6
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• pp.538-543
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• 2008

Recently a nano-scale diamond is possible to manufacture forms of powder(below 100 nm) by new processing of explosion or deposition method. Using a sintering of nano-scale diamond is possible to manufacture of grinding tools. We have need of a processing development of coated uniformly inorganic to prevent an abnormal grain growth of nano-crystal and bonding obstacle caused by sintering process. This paper, in order to improve the sintering property of nano-scale diamond, we coated ZnO thin films(thickness: $20{\sim}30\;nm$) in a vacuum by ALD(atomic layer deposition) Economically, in order to deposit ZnO all over the surface of nano-scale diamond powder, we used a new modified fluidized bed processing replaced mechanical vibration effect or fluidized bed reactor which utilized diamond floating owing to pressure of pulse(or purge) processing after inserted diamond powders in quartz tube(L: 20 mm) then closed quartz tube by porosity glass filter. We deposited ZnO thin films by ALD in closed both sides of quartz tube by porosity glass filter by ALD(precursor: DEZn($C_4H_{10}Zn$), reaction gas: $H_2O$) at $10^{\circ}C$(in canister). Processing procedure and injection time of reaction materials set up DEZn pulse-0.1 sec, DEZn purge-20 sec, $H_2O$ pulse-0.1 sec, $H_2O$ purge-40 sec and we put in operation repetitive 100 cycles(1 cycle is 4 steps) We confirmed microstructure of diamond powder and diamond powder doped ZnO thin film by TEM(transmission electron microscope) Through TEM analysis, we confirmed that diamond powder diameter was some $70{\sim}120\;nm$ and shape was tetragonal, hexagonal, etc before ALD. We confirmed that diameter of diamond powders doped ZnO thin film was some $70{\sim}120\;nm$ and uniform ZnO(thickness: $20{\sim}30\;nm$) thin film was successfully deposited on diamond powder surface according to brightness difference between diamond powder and ZnO.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.3
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• pp.591-595
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• 2007

There are eight kinds of formulas for invigorating the liver to cure its asthenic syndrome based on the types of preparation formulas Began-tang, Boganhwan, Bogansan, Bogandan, Boganeum, Boganjoo, Boganjeon and Bogango. Another formula called Bocheonghwan is to invigorate the green colour of liver. There are 22 kinds of Bogan-tang, 12 kinds of Boganhwan, 25 kinds of Bogansan, one kind of Bogandan, one kind of Boganeum, one kind of Boganjoo, one kind of Boganjeon, one kind of Bogango, and two kinds of Bocheonghwan. Combination of herbal medicines, carried out in formulas for invigorating the liver, consists of various kinds depending on medical scientists' personal experience in medical treatment without any general principles, which makes it difficult to apply it to clinical use. The objectives of this study lie in theoretical establishment of Bogan-tang for curing the asthenic syndrome of liver through analyzing the component medicines and combination principles of Hyeongok's Bogan-tang, and furthermore, maximizing the clinical use of Began-tang. This study analyzed the component medicines and combination principles of Hyeongok's Bogan-tang based on the theory for properties and tastes of herbal medicines from the ${\ulcorner}$yellow Emperor's Canon of Internal Medicine${\lrcorner}$ , the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, dispatcher herbal medicine, and the five elements doctrine. Hyeongok's Began-tang is an odd prescription, composed of 7 kinds of ingredients No.1 Radix Angelicas Sinensis (2don;7.5g), No.2 Rhizoma Chuanxiong (1don;3.75g), No.3 Radii Polygoni Multiflori (1don), No.4 Fructus Lycii (1don), No.5 Cortex Cinnamomi (1don), No.6 Rhizoma Gastrodiae (1don), and No.7 Radix Glycyrrhizae (1don). There are three methods for curing the asthenic syndrome of liver according to the five elements doctrine invigorating the liver, invigorating the kidney and purging the lung. First, if you suffer from the asthenic syndrome of the liver, you need to invigorate your liver. There are two available methods, including taste and property invigoration according to the theory for properties and tastes of herbal medicines. They each imply the pungent taste and the warm property invigorate the liver. In the case of taste invigoration, two herbal medicines with pungent taste, Radix Angelicas Sinensis and Rhizoma Chuanxiong, are combined into the principal and assistant herbal medicine, respectively. For property invigoration, two herDal medicines with the warm property, Cortex Cinnamomi and Rhizoma Gastrodiae, are combined into adjuvant herbal medicines. Secondly, if you suffer from the asthenic syndrome of the liver, you need to invigorate your kidney which is mother in the mother-child relationship in inter-promotion among the five elements. There are two methods to invigorate the kidney, including taste and property invigoration according to the theory for properties and tastes of herbal medicines. They each mean the bitter taste and the cold property invigorate the kidney. Therefore, it is important to use bitter herbal medicines for taste invigoration and cold ones for property invigoration. Both Differ and cold herbal medicines, Radix Polygoni Multiflori and Fructus Lycii, are combined into adjuvant herbal medicines. Lastly, if you suffer from the asthenic syndrome of the liver, you need to purge your lung which is an element being surpassed in the relationship between the elements surpassed and ones not surpassed in inter-restraint among the five elements. There are two methods to purge the lung, which include taste and property invigoration according to the theory for properties and tastes of herbal medicines. Taste invigoration means to purge the lung with pungent taste and property invigoration to purge the lung with warm property. Therefore, it is important to use pungent herbal medicines for taste invigoration and warm ones for property invigoration. Both pungent and warm herbal medicines, Radix Angelicas Sinensis and Rhizoma Chuanxiong, were combined to invigorate and purge the lung. In addition, Radix Glycyrrhizae are combined as dispatcher herbal medicine, harmonizing all the herbal medicines composing the formula. First, to cure the asthenic syndrome of the liver, the methods of invigorating the liver and the kidney, and purging the lung should be used according to the five elements doctrine. Secondly, herbal medicines appropriate for those treatment methods should be chosen according to the theory for properties and tastes of herDal medicine and thirdly, the combination of those herbal medicines should be carried out according to the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, dispatcher herbal medicine. As a good example, Hyeongok's Bogan-tangon is combined according to the above theories. In conclusion, this formula was created by applying to the theory for properties and tastes of herbal medicines.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.5
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• pp.282-296
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• 2006

In a wireless client server environment, data broadcasting is an efficient data dissemination method; a server broadcasts data, and some of broadcasted data are cached in a mobile client's cache to save the narrow communication bandwidth, limited resources, and data access time. A server also broadcasts invalidation reports to maintain the consistency between server data and a client's cached data. Most of existing works on the cache consistency problems simply purge the entire cache when the disconnection time is long enough to miss the certain amount(window size) of IRs. This paper presents a cache invalidation method to increase mobile clients' cache reusability in case of a long disconnection. Instead of simply dropping the entire cache regardless of its consistency, a client estimates the cost of purging all the data with the cost of selective purge. If the cost of dropping entire cache is higher, a client maintains the cache and selectively purge inconsistent data using uplink bandwidth for validation request. The simulation results show that this scheme increases the cache reusability since it effectively considers the update rates and the broadcast frequencies of cached data in estimating the cost of cache maintenance.