• Transactions of the Korean hydrogen and new energy society
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• v.25 no.2
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• pp.161-172
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• 2014

Hydrogen, which can be produced from abundant and widely distributed renewable energy resources, seems to be a promising candidate for solving the concerns for improving energy security, urban air pollution, and reducing greenhouse gas emissions. The two primary motivating factors for hydrogen economy are fossil fuel supply limitations and concerns about global warming. But the safety issues associated with hydrogen economy need to be investigated and fully understood before being considered as a future energy source. Limited operating experience with hydrogen energy systems in consumer environments is recognised as a significant barrier to the implementation of hydrogen economy. To prevent unnecessary restrictions on emerging codes, standards and local regulations, safety policies based on real hazards should be developed. This article studies briefly the direct impact-distances from hazard events such as hydrogen release and jet fire, and damage levels from hydrogen gas explosion in a confined space. Based on the direct impact-distances indicated in the accident scenarios and consumer environments in Korea, the safety policies, which are related to hydrogen filling station, hydrogen fuel cell car, portable fuel cell, domestic fuel cells, and hydrogen town, are suggested to implement hydrogen economy. To apply the safety policies and overcome the disadvantages of prescriptive risk management, which is setting guidance in great detail to management well known risk but is not covering unidentified risk, hybrid risk management model is also proposed.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.20
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• pp.9021-9025
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• 2014

Background: Breast cancer (BC) is the most common cancer among females in Turkey. Predictors affecting the breast self-examination (BSE) performance vary in developing countries. Objective: To determine the frequency of BSE performance and predictors of self-reported BSEs among women in the capital city of Turkey. Materials and Methods: This cross-sectional study was conducted on 376 Turkish women using a self-administered questionnaire covering socio-demographic variables and BSE-related features. Results: Of the participants, 78.7% (N=296) reported practicing BSE, whereas 9.5% (N=28) were implementing BSE regularly on a monthly basis, and only 5.7% (N=17) were performing BSE regularly within a week after each menstrual cycle. Multivariate logistic regression modeling revealed that BSE performance was more likely in younger age groups [20-39 years] (p=0.018, OR=3.215) and [40-49 years] (p=0.009, OR=3.162), women having a family history of breast disease (p=0.038, OR=2.028), and housewives (p=0.013, OR=0.353). Conclusions: Although it appears that the rates of BSE performers are high, the number of women conducting appropriate BSE on a regular time interval basis is lower than expected. Younger age groups, family history of breast diseases and not being employed were identified as significant predictors of practicing BSE appropriately. Older age and employment were risk factors for not performing BSE in this sample.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.2
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• pp.119-125
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• 2004

This paper is described the indirect induction heated boiler system and induction heated hot air producer using the voltage-fed series resonant high-frequency inverter which can operate in the frequency range from 20〔KHz〕 to 50〔KHz〕. A specially designed Induction heater, which is composed of laminated stainless assembly with many tiny holes and interconnected spot welding points between stainless plates, is inserted into the ceramic type vessel with external working coil. This working coil is connected to the resonant inverter. In the induction heater, it's primary heating section creates low-pressure saturated steam and secondary heating section generates heat distribution evaporating fluid from the turbulence fluid which is flowing through the vessel. The operating performances of this unique appliance in next generation and its effectiveness are evaluated and discussed from the practical point of view.

• Journal of KIISE:Databases
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• v.32 no.3
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• pp.285-296
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• 2005

In mobile distributed systems the data on the air can be accessed by a lot of mobile clients. And, we need an indexing scheme in order to energy-efficiently access the data on the wireless broadcast stream. In conventional indexing schemes, they use the values of primary key attributes and construct tree-structured index. Therefore, the conventional indexing schemes do not support content-based retrieval queries such as partial-match queries. In this paper we propose an indexing scheme, called B2V-Tree, which supports partial match queries on wireless broadcast data stream. For this purpose, we construct a tree-structured index which is composed of bit-vectors, where the bit-vectors are generated from data records through multi-attribute hashing.

• Atmosphere
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• v.20 no.3
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• pp.307-318
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• 2010

This study investigates the generation and movement of low-concentration $CO_2$ observed in Gosan during summer from 2002 to 2006. For analysis, additional $CO_2$ data in Anmyeondo, Ryori, Barrow, and Minamitorishima as well as NOAA/ESRL daily global $CO_2$ fields, background trajectories data, and 850 hPa wind fields are also used. Based on analyses using various observed data, we classified three types of low-concentration $CO_2$ in Gosan according to its origin: i) the origin of the Siberian continental, in which the consumption of $CO_2$ is active due to photosynthesis from broad forests, ii) the origin of Okhotsh and Artic seas, in which the low-concentration $CO_2$ is dominant due to high primary productivity by a plankton bloom, and iii) the origin of the Northwestern Pacific which is related to the entry of air mass from high latitudes. These results show that the low-concentration $CO_2$ observed in Gosan during summer is not originated from the Pacific oceans as known in previous studies, but originated from high latitude regions such as the Siberian continental and the Okhotsh and Artic seas.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.1
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• pp.64-74
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• 2017

In this study, we have analyzed relationship between the measured Water Soluble Organic Carbon (WSOC) concentrations and the estimated aerosol water content of $PM_{10}$ (particulate matter with an aerodynamic diameter of less than or equal to $10{\mu}m$) for the period between September 2006 and August 2007 at Seoul, Korea. Water content of $PM_{10}$ was estimated by using a gas/particle equilibrium model, Simulating composition of Atmospheric Particles at Equilibrium 2 (SCAPE2). The WSOC concentrations showed low correlation with Elemental Carbon (EC), but Water Insoluble Organic Carbon (WISOC) were highly correlated with EC. It seemed that hydrophilic groups were produced by secondary formation rather than primary formation. As with the previous studies, WSOC showed good correlation with secondary ions ($NO_3{^-}$, $SO_4{^{2-}}$, $NH_4{^+}$), especially WSOC was highly correlated with $NO_3{^-}$ that is a secondary ion formed by photochemical oxidation from more local sources than $SO_4{^{2-}}$. No apparent correlation between the measured WSOC and estimated water content was observed. However, WSOC showed good correlation with estimated water content when it was assumed that relative humidity was higher than the deliquescence relative humidity of the system. In conclusion, WSOC is correlated with water content by hygroscopic ions and it is expected that nitrate play an important role among the water content and WSOC.

• Journal of Chest Surgery
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• v.25 no.12
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• pp.1508-1515
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• 1992

Between 1975 and 1992, forty five patients with trachea stenosis received tracheoplasty for relief of obstruction. The causes of airway problem are brain contusion[19 cases, 40%], cerebrovascular disease[3 cases, 7%], drug intoxication[8 cases, 18%], psychotic problem[2 cases, 4%], trachea tumor[3 cases, 7%], adult respiratory distress syndrome[9 cases, 20%] and direct trauma[1 case, 2%]. Direct causes of trachea stenosis were complications of tracheostomy[36 cases, 80%], complications of nasotracheal intubation[5 cases, 11%], tumor[3 cases, 6%] and trauma[1 case, 2%]. Thirty one patients underwent the sleeve resection and end-to-end anastomosis. Five patients performed a wedge resection and end-to-end anastomosis. Forteen patients received the Montgomery T-tube for relief of airway obstruction. Four patients have done simple excision of granulation tissue. Two, subglottic stenosis patients were received Rethi procedure[anterior division of cricoid cartilage, wedge partial resection of lower thyroid cartilage and Montgomery T-tube molding] and the other subglottic stenosis patient underwent permanent trachea fenestration. Including cervical flexion in all patients postoperatively, additional surgical techniques for obtain tension-free anastomosis were hyoid bone release technique in two cases, and hilar mobilization, division of inferior pulmonary ligament and mobilization of pulmonary vessel at the pericardium were performed in one case. Cervical approach was used in 39 cases, cervicomediastinal in 12 cases and transthoracic in one case. Complications of tracheoplasty were formation of granulation tissue at the anastomosis site[3 cases], restenosis[9 cases], trachea-innominate artery fistula[2 cases], wound infection[2 cases], separation of anastomosis[2 cases], air leakage[3 cases], injury to a recurrent laryngeal nerve[temporary 8 cases, permanent 2 cases] and hypoxemia[1 case]. Surgical mortality for resection with primary reconstruction was 6.7%, with one death due to postoperative respiratory failure and two deaths due to tracheo-innominate artery fistula.

• Journal of Chest Surgery
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• v.26 no.6
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• pp.470-474
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• 1993

A clinical evaluation was performed on 56 patients[ 60 cases ] of open thoracotomy in spontaneous pneumothorax who were admitted and treated at department of Thoracic and Cardiovascular Surgery, Chung Ang University, Yong San Hospital during the past 3 years from March 1990 to February 1993. The results were as follows. 1. The sex ratio was male predominence [ M:F = 7:1 ]. 2. The most common age group were 2nd, 3rd decades. 3. The most common chief complaints were dyspnea and chest pain [46.3% ]. 4. The etiologic factors of spontaneous pneumothorax were primary spontaneous pneumothorax [ 78.3%], secondary tuberculosis [ 18.3%], and others [ 3.4% ]. 5. The site of spontaneous pneumothorax was 50% in right, 40% in left, and 10% in both. 6. The state of activity on attack was almost in the usual life [ 98.3% ]. 7. Average height was 172.5 $\pm$ 5.39 cm in male and 164.0 $\pm$ 3.51 cm in female, average weight was 59.1 $\pm$ 7.06 kg in male and 52.0 $\pm$ 4.97 kg in female. 8. The common indications of open thoracotomy were recurrence [ 34.4% ] and persistent air leakage [ 17.8% ]. 9. The operative procedures were bullectomy [ 73.3% ], partial resection [ 11.7% ], lobectomy [ 11.7% ], and others [ 3.3% ]. 10. The most frequent location of bulla or bleb were apical segment of RUL [ 43.3 % ] and apicoposterior segment of LUL [ 40.0% ]. 11. The number of visible bulla or bleb were mainly 1 to 5, and size was about 1 to 3 cm.

• Korean Journal of Materials Research
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• v.23 no.5
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• pp.276-280
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• 2013

Coal tar is the primary feedstock of premium graphitizable carbon precursor. Coal tars are residues formed as byproducts of thermal treatments of coal. Coal tar pitches were prepared through two different heat treatment schedules and their properties were characterized. One was prepared with argon and oxidation treatment with oxygen; the other was prepared with oxygen treatment at low temperature and then argon treatment at high temperature; both used coal tar to prepare coal tar pitches. To modulate the properties, different heat treatment temperatures ($300{\sim}400^{\circ}C$) were used for the coal tar pitches. The prepared coal tar pitches were investigated to determine several properties, such as softening point, C/H ratio, coke yield, and aromaticity index. The coal tar pitches were subject to considerable changes in chemical composition that arose due to polymerization after heat treatment. Coal tar pitch showed considerable increases in softening point, C/H ratio, coke yields, and aromaticity index compared to those characteristics for coal tar. The contents of gamma resin, which consists of low molecular weight compounds in the pitches and is insoluble in toluene, showed that the degree of polymerization in the pitches was proportional to C/H ratio. Using an oxidizing atmosphere like air to prepare the pitches from coal tar was an effective way to increase the aromaticity index at relatively low temperature.

• Journal of the Korean Society of Clothing and Textiles
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• v.14 no.2
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• pp.85-97
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• 1990

This study investigates, through the Ka-rae-ban-cha-do(가예반차도) in the Ka-rae-do-gam­eui-gue (가예도감의궤), how the system of costume used in ceremony exchanged during the middle, late the Yi dynasty and in the period of introducing Wastern civilization. The procedure of the royal marriage is also studied here. The procedures of Ka-rae were divided into the six traditional etiguettes(륙예) : Nap-che (납채) , Nap-gyng(납징), Go-gi(고기), Chaik-bi(책비), Chin-young(친영), and Dong-roe(동뢰). The change of the general structure and characteristic of the costume used in the ceremony in Ka-rae-ban-cha-do are as follows: The costume in Ka-rae-ban-cha-do can be divided into the Guard costume (호위복식) and the Ceremonial arms costume (의장복식). The most formal attire of the Guard costume, Yangkwan-Chobok (양관-조복) and Samo -Danryeong(사모-단령) with Huygpai(흉배) can be seem only in the Ka-rae of late king's. Of the Ceremonial arms costume, the most outstanding was Hongkun- Hongeui (홍건-홍의), which showed up in almost all Ka-rae-ban-cha-do. Heukkun-Changos$\cdot$Deogrei (흑건-창옷$\cdot$더그레) were worn as well. In the style of costume emphasis convenience and practicality rather than on beauty, because they had to carry the arms used in ceremony with them nevertheless by using primary colors it was very colorful. This costume in Ka-rae-ban-cha-do has little difference, but great changes are shown in Sunjongsunjongbi Ka-rae-ban-cha-do (순종순종비가례반차도). Most costume of the past was replaced with western hat and suit, so the duplicate state of our costume and western costume came into existence during the period of introducing western civilization.