• Progress in Medical Physics
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• v.18 no.2
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• pp.98-106
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• 2007

In June 2005, Yonsei University Medical Center, Severance Hospital upgraded a full-PACS system by adding twenty (5 mega pixels) Totoku ME511L flat panel LCD display devices for diagnostic interpretation purposes. Here we report upon the quantitative (or visual) acceptance testing of the twenty Totoku ME511L display devices for reflection, luminance response, luminance spatial dependency, resolution, noise, veiling glare, and display chromaticity based on AAPM TG 18 report. The tools used in the tests included a telescopic photometer, which was used as a colorimeter, illuminance meter, light sources for reflection assessment, light-blocking devices, and digital TG18 test patterns. For selected 8 flat panel displays, mean diffuse reflection coefficient ($R_d$) was $0.019{\pm}0.02sr^{-1}$. In the luminance response test, luminance ratio (LR), maximum luminance difference ($L_{max}$), and deviation of contrast response were $550{\pm}100,\;2.0{\pm}1.9%\;and\;5.8{\pm}1.8%$, respectively. In the luminance uniformity test, maximum luminance deviation was $14.3{\pm}5.5%$ for the 10% luminance of the TG18-UNL10 test pattern. In the resolution test with luminance measurement method, percent luminance (${\Dalta}L$) at the center was $0.94{\pm}0.64%$. In all cases of noise testing, rectangular target In every square in the three quadrants was visible and all 15 targets except the smallest one in the every corner pattern and the center pattern. The glare ratio (GR) was $12,346{\pm}1,995$. The color uniformity, (u',v'), was $0.0025{\pm}0.0008$. Also, the research results of qualify control guideline of primary disply devices suitable for domestic circumstance are presented All test results are in-line with the criteria recommended by AAPM TG18 report and are thus fully acceptable for diagnostic image interpretation. As a result, the acceptance testing schedule described provides not only an acceptance standard but also guidelines for quality control, optimized viewing conditions, and a means for determining the upgrading time of LCD display devices for diagnostic interpretation.

• Korean Journal of Heritage: History & Science
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• v.53 no.1
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• pp.64-87
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• 2020

The cultural property management system of Korea was established based on the modern cultural assets acts and the old imperial estate management system enacted during the Japanese occupation. Academics have researched the cultural property management system oriented on the modern cultural assets acts, but few studies have been conducted into the old imperial estate management system, which is another axis of the cultural property management system. The old imperial estate was separated from the feudal capital by the Kabo Reform, but was dismantled during the colonial invasion of Japan and managed as a hereditary property of the colonial royal family during the Japanese colonial period. After establishment of the government, the Imperial Estate Act was enacted in 1954 and defined the estate as a historical cultural property managed by the Imperial Estate Administration Office. At this time, imperial estate property that was designated as permanent preservation property was officially recognized as constituting state-owned cultural assets and public goods in accordance with Article 2 of the Act's supplementary provisions during 1963, when the first amendment to the Cultural Property Protection act was implemented. In conclusion, Korea's cultural property formation and cultural property management system were integrated into one unit from two different sources: modern cultural assets acts and the old imperial estate property management system. If the change of modern cultural assets acts was the process of regulating and managing cultural property by transplanting and applying regulations from Japan to colonial Joseon, the management of the imperial estate was a process by which the Japanese colonized the Korean Empire and disposed of the imperial estate. Independence and the establishment of the government of the Republic of Korea provided the opportunity to combine these two different streams into one. Finally, this integration was completed with the establishment of the Protection of Cultural Properties Act in 1962.

• Korean Journal of Heritage: History & Science
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• v.53 no.3
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• pp.24-41
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• 2020

The engraved line expression in metal crafts is a detailed technique of carving or decorating metal surfaces. This technique engraves a line using a tool on the surface of a metal craft. This technique was used extensively in articles made of various metal materials during the Goryeo Dynasty, and the range of patterns that could be expressed and the width of users was wide. In this paper, based on relics and literature, the concept of line representation of this engraving technique used in the metal crafts of the Goryeo Dynasty and the perceptions and terms of the Goryeo Dynasty were examined. In addition, the users engaged in this craft and the specific patterns and patterns of decoration were reviewed. Through these means, it was possible to confirm various aspects of a technique that was thought previously to involve just simple expression of lines using tools. In addition, through the literature, Geumseokmun Gate, and relics currently being transmitted, it was possible to confirm the utilization patterns of techniques used in various types of objects. Various uses have led to the combination with other metal craft techniques that were popular at the time, and while utilizing unique characteristics of the techniques, this maximized the molding of various patterns. In the meantime, it is true that the intaglio technique in metal crafts has not received much attention compared to the decoration techniques of other metal crafts, such as inlay, embossing, and openwork techniques in which decorative effects are maximized due to the recognition that the technique was used so widely in relics. However, the universality of the technique is premised on its wide use across all eras. As such, it was used in metal craft relics that reflect the various cultural characteristics of Korea and various cultural aspects that are currently passed down. On the one hand, technology has been passed down as a form of intangible heritage that embodies a longstanding craft culture which continues to the present in the fields of sculpture and intangible cultural properties. As such, the universality of Seongak contains many cultural meanings. In addition, the uniqueness of the technique is distinct, and it is deeply related to Goryeo, who was in charge of the use of technology and craftsmanship of the Joseon Dynasty and the metal craft technology that is currently handed down. I think research on future techniques should be continued in depth.

• Korean Journal of Heritage: History & Science
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• v.53 no.3
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• pp.164-183
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• 2020

In the textile culture of the Joseon Dynasty, the historic record of Banpo is fragmentary and contains many missing details. The main reason is a lack of associated literature, and it is also significant that the actual substance used is not clear at present. Banpo is a kind of cotton, but this has not been confirmed in the traditional textiles that are currently handed down. The word Ban [斑] in Banpo means "stain", and the letter Po [布] means "fabric". At the border of white discourse, Banpo did not receive attention as a research topic. This study is an attempt to restore some of the textile culture of the Joseon Dynasty through Banpo. Banpo is not just limited to the Joseon Dynasty; it is an important material for examining the development of textile culture and exchange in East Asia. This study was broadly divided into three parts. First, the record and meaning of Banpo during the Joseon Dynasty were examined. Records of Banpo can be seen from the early Joseon period during King Sejo and Seongjong, and the production and actual use of Banpo have been confirmed. Banpo was maintained until the beginning of the 20^th century, but is no longer observed. Banpo is a woven fabric made of cotton yarn dyed in many colors and has appeared in Southeast Asia since ancient times. In East Asia, there are other fabrics similar to Banpo, such as Ho [縞], Sum [纖], and Chim [綅]. In particular, the correlation between Banpo and Ho is an important link in understanding Banpo in the Joseon Dynasty. Second, the meaning of Banpo was examined from various angles through comprehensive analysis of Chinese and Japanese literature records and cases. The appearance and development of Banpo moved in sync with the period when cotton was introduced into East Asia. In East Asia, cotton was introduced and produced in earnest from the end of the Song Dynasty to the beginning of the Yuan Dynasty, and the meaning of Banpo was diversified. In China, the name of Banpo was changed to Hwapo [花布], Gizapo [碁子布], Gizahwapo [棋子花布], etc. Japan was late to introduce cotton and developed it in acceptance of the changed meaning. In Japan, use of the name Banpo is not on record, but a Ryujo [柳條] fabric of the same type as banpo has been identified. This Ryujo is the same concept as Ho and Hwapo, and later merged into Ho. Names such as Ho, Hwapo, Banpo, etc. were used differently in each country, but the form was shared across East Asia. Third, based on the meaning of Banpo shared in East Asia, the format of Banpo in the Joseon Dynasty was classified. The format of Banpo in the Joseon Dynasty can be divided into grid and striped versions. The name Banpo disappeared over time, but the form remained and was passed down until recently. I hope that this study will help restore Banpo in the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.87-95
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• 2016

This study examined the characteristics of the hourly demand of city gas in Korea and proposed multiple regression models to obtain precise estimates of the hourly demand of city gas. Forecasting the hourly demand of city gas with accuracy is essential in terms of safety and cost. If underestimated, the pipeline pressure needs to be increased sharply to meet the demand, when safety matters. In the opposite case, unnecessary inventory and operation costs are incurred. Data analysis showed that the hourly demand of city gas has a very high autocorrelation and that the 24-hour demand pattern of a day follows the previous 24-hour demand pattern of the same day. That is, there is a weekly cycle pattern. In addition, some conditions that temperature affects the hourly demand level were found. That is, the absolute value of the correlation coefficient between the hourly demand and temperature is about 0.853 on average, while the absolute value of the correlation coefficient on a specific day improves to 0.861 at worst and 0.965 at best. Based on this analysis, this paper proposes a multiple regression model incorporating the hourly demand ahead of 24 hours and the hourly demand ahead of 168 hours, and another multiple regression model with temperature as an additional independent variable. To show the performance of the proposed models, computational experiments were carried out using real data of the domestic city gas demand from 2009 to 2013. The test results showed that the first regression model exhibits a forecasting accuracy of MAPE (Mean Absolute Percentage Error) around 4.5% over the past five years from 2009 to 2013, while the second regression model exhibits 5.13% of MAPE for the same period.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.10
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• pp.441-450
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• 2014

The stock market is constantly changing and sometimes the stock prices unaccountably plummet or surge. So, the stock market is recognized as a complex system and the change on the stock prices is unpredictable. Recently, many researchers try to understand the stock market as the network among individual stocks and to find a clue about the change of the stock prices from big data being created in real time from Internet. We focus on the correlation between the stock prices and the human interactions in Internet especially in the stock message boards. To uncover this correlation, we collected and investigated the articles concerning with 57 target companies, members of KOSPI200. From the analysis result, we found that there is no significant correlation between the stock prices and the article volume, but the strength of correlation between the article volume and the stock prices is relevant to the stock return. We propose a new method for recommending stock portfolio base on the result of our analysis. According to the simulated investment test using the article data from the stock message boards in 'Daum' portal site, the returns of our portfolio is about 1.55% per month, which is about 0.72% and 1.21% higher than that of the Markowitz's efficient portfolio and that of the KOSPI average respectively. Also, the case using the data from 'Naver' portal site, the stock returns of our proposed portfolio is about 0.90%, which is 0.35%, 0.40%, and 0.58% higher than those of our previous portfolio, Markowitz's efficient portfolio, and KOSPI average respectively. This study presents that collective human behavior on Internet stock message board can be much helpful to understand the stock market and the correlation between the stock price and the collective human behavior can be used to invest in stocks.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.4
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• pp.1781-1791
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• 2013

The present study was intended to measure the level of psychosocial stress and fatigue symptom according to the various characteristics such as sociodemographic, health-related, job-related, job stress factors, and psychosocial factors among nurses working at ward and operating room in university hospitals, and to reveal the relation between these factors and psychosocial stress and fatigue symptom. The self-administered questionnaires were given to 220 nurses working at ward, and 147 nurses working at operating room in 4 participating hospitals located in Daejeon City during the period from July 1st to Aug 31st, 2012. As a results, the factors related to the psychosocial stress of nurses working at ward were age, subjective health status, job career, satisfaction of work, fit to the job, job demand, job control, coworker support, self-esteem, locus of control, type A behavior pattern. In operating room, there were age, sleep hours, subjective health status, job career, physical burden of work, satisfaction of work, fit to the job, consider quitting the job, job demand, job control, type A behavior pattern. The factors related to the fatigue symptoms of nurses working at ward were age, leisure time, subjective health status, satisfaction of work, consider quitting the job, job demand, locus of control, type A behavior pattern. In operating room, there were age, subjective health status, physical burden of work, supervisor support, coworker support, locus of control. Based on the study results, we suggest that the factors related to psychosocial stress and fatigue symptom of nurses were different from working station. We need development and application of programs to keep under management psychosocial stress and fatigue symptom.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.206-214
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• 2018

This study was conducted from August 2017 to May 2018. Beer was prepared by different ratio of rice and malt and different types of beer, and quality analysis were conducted. The ratio of rice and malt was divided into 0:100 (S0), 20:80 (S1), 40:60 (S2), 60:40 (S3) and 80:20 respectively. We compared the characteristics of the mashing methods(infusion and decoction method) and investigated the characteristics of different types of beer (lager, ale, wheat beer) using yeast (bottom and top yeast). Even with different ratios of rice and malt, normal infusion time was observed and the iodine test was confirmed to be normal. Also, the mashing proceeded normally and the sugar content of the primary wort was between $21.0{\sim}21^{\circ}brix$. In mashing method, the mash concentration, color and flavor of wort were the highest in the three mash method(decoction method). During the fermentation period of beer, the sugar content, pH and yeast number did not differ significantly depending on the ratio of rice and malt, and the type of yeast. Higher alcohol and esters also had no correlation with the ratio of rice to malt, and wheat beer was somewhat higher. The higher the ratio of rice, the more the color intensity(EBC) decreased, the bitter unit(BU) and the preference decreased. When the rice ratio was higher than the malt rate, the degree of preference decreased significantly. Based on the results of this study, it is expected that the rice ratio will be less than the malt ratio and the flavor of the wort will be improved by using the deccoction method. If the malt is supplemented with the use of the special malt and the various hops according to the beer type, it may be helpful to manufacture rice beer.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.4
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• pp.117-124
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• 2009

The purpose of the study was to improve quality of high volume fly ash concrete. The study evaluated on the possibility of early quality improvement of high volume fly ash concrete with early strength gain admixture ('GA' below) developed by the preceding research. The study regarded applying naphthalene admixture ('NA' below) to mix proportion substituting FA 15 % to be plain. In the event of substituting FA 20, 25 and 30 %, the study compared engineering properties of concrete with plain by applying GA. Because of features of fresh concrete, fluidity falls down when GA is applied. Therefore, its use amount shall be increased. Only, in W/B 60 %, it was beneficial since slump loss was reduced about 35~70 mm than plain. The study could see that AE use should be increased proportionally since air content was reduced by coming from AE absorption operation of unburned coal content included in FA according to an increase in the amount of FA use. Reduction effect of bleeding could be anticipated since the amount of bleeding appeared at least in FA 20 %. Because of hardened concrete, time of setting appeared in the same level as plain when GA was applied. Therefore, it is judged that delay of setting can be reduced. In compressive strength, the study could check the same strength development as plain when GA was applied, having nothing to do with W/B and curing temperature. However, it is thought that we shall pay attention to GA use in the event of FA 30 % substitution. Freezing and melting resistance had less early value than plain. However, it is judged that there will be no problem of frost resistance since there is no a large difference between freezing and melting resistance and plain in overall. In accelerated neutralization, it was analyzed that a problem of weakening in neutralization appointed as a demerit when FA was applied in mass in proportion with GA use could be settled to some extent.

• The Korean Journal of Physiology
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• v.13 no.1_2
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• pp.1-12
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• 1979

To evaluate the present status of physical fittness of Korean long distance runners, body fat, pulmonary functions, maximal oxygen intake and oxygen debt were measured in 5 elite marathoners (A group), 6 college student runners (B group) and 3 middle school student runners (C group). After laboratory tests, full course marathon running was performed in 2 elite marathoners during which their heart rates were monitored continuously. The results are summerized as follows: 1) Total body fat in all three groups are in the range of 13-15% of their body weight. 2) In all three groups, average values of various pulmonary functions were within the normal limits, but those of tidal volume were higher and respiratory rate were lower in comparison to normal values. These phenomena may represent respiratory adaptations against training. The average resting oxygen consumptions in A,B and C were $322{\pm}23$, $278{\pm}14$ and $287{\pm}16$m1/min, respectively. 3) In all three groups, resting blood pressures were in the normal range, but the resting heart rate was slightly lower in groups A $(56{\pm}3\;beats/min)$ and B $(64{\pm}2\;beats/min)$ and higher in group C $(82{\pm}9\;beats/min)$ in comparison to normal values. These changes in cardiovascular functions in marathoners may also represent adaptive phenomena. 4) During treadmill running the minute ventilation and oxygen consumption of the runners increased lineally with work load in all three groups. When the oxygen consumption was related to heart rate, it appeared to be a exponential function of the heart rate in all three groups. 5) The average maximal heart rates during maximal work were $196{\pm}3$, $191{\pm}3$ and $196{\pm}5\;beats/min$ for groups A,B and C, respectively. Maximal oxygen intakes were $84.2{\pm}3.3\;ml/min/kg$ in group A, $65.2{\pm}1.1\;ml/min/kg$ in group B and $58.7{\pm}0.4\;ml/min/kg$ in group C. 6) In all three groups, oxygen debts and the rates of recovery of heart rate after treadmill running were lower than those of long ditsance runners reported previously. 7) The 40 km running time in 2 elite marathoners was recorded to be $2^{\circ}42'25'$, and their mean speed was 243 m/min (ranged 218 to 274 m/min). The heart rate appeared to increase lineally with running speed, and the total energy expenditure during 40 km running was approximately 1360.2 Calories. From these it can be speculated that if their heart rates were maintained at 166 beats/min during the full course of marathon running, their records would be arround $2^{\circ}15'$. Based on these results, we may suspect that a successful long distance running is, in part, dependent on the economical utilization of one's aerobic capacity.