• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.9
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• pp.1325-1330
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• 2010

The breakdown of any critical component of a turbine results in the outage of power plants. Unexpected failure decreases equipment utilization and causes enormous economic losses. Currently, we conduct conservative preventive maintenance for a maintenance period that is proposed by a vendor. In the rapidly changing business environment, reliability-based maintenance is required in order to remain competitive and reduce maintenance costs while maintaining the reliability of equipment. In order to determine an appropriate maintenance period for guaranteeing reliability, we must determine the failure probability by carefully analyzing the failure history of the equipment. In this study, we created a database of failure history for power-plant turbines, predicted the best repair time using the Weibull function, and investigated how the appropriate maintenance cycle can be determined.

• Journal of the Korean Society of Food Culture
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• v.31 no.6
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• pp.541-553
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• 2016

Medicinal porridge (藥粥) is made by putting rice or grains into a pot and boiling with water until a semi-liquid texture is obtained. Porridge is digested fast and absorbed by the body. Children or elderly people with weak digestive ability can eat it without difficulty. The authors of this literature focused on utilization of mung bean porridge (Nokdu-juk) based on SeungjeongwonIlgi (承政院日記), which is the daily record of the Royal Secretariat of the Joseon Dynasty from 1623 to 1910. Four cases were found. The first case used mungbean for treating fever diseases (熱症), the second as a meal alternative, the third for wound recovery, and the last case described the culture of the joseon dynasty. According to the actual cases in SeungjeongwonIlgi (承政院日記), mung bean porridge (Nokdu-juk) was actively used to lower fever and strengthen the spleen and stomach. When suffering from the after effects of a malignant tumor or serious liver disease (肝病), an infectious disease, or a serious physical wound, people ate mung bean porridge (Nokdu-juk). It is suggested that mung bean porridge (Nokdu-juk) can be used as an alternative food treatment for the current medical field due to the prevalence of pain-killers and psychotropic drug abuse.

• Journal of Family Resource Management and Policy Review
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• v.24 no.3
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• pp.79-102
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• 2020

This study aims to provide basic resources for the construction of the archives on the official family service history in Korea. The study collected records of family policies and official family service from 1948 to 2019 and thereafter attempted to classify the official family service. In addition, experts were consulted to diagnose compliance with research contents and directions, investigate priorities of the family policies, and provide opinions on the elements of each process of archiving. The results of this study were as follows. First, there were five areas of concern to be considered in the process of establishing an archive of official family services: concept, scope, collection, arrangement, preservation, and utilization. Second, the findings suggest which processes are critical to developing a sustainable and systematic archive system for the official family service history. The construction of the archives will provide a platform for understanding the contents of integrated family policies and inform the direction of future family policies in Korea. In addition, these archives will be an important factor in building a solid Korean national identity.

• Journal of architectural history
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• v.32 no.4
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• pp.19-33
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• 2023

This study investigated the architectural expression of Taekpungdang(澤風堂, The Pond and Wind House) built by the Neo-Confucianist Taekdang Lee Sik(澤堂 李植, 1584~1647) from the perspective of the symbolic system of the Zhōuyì(『周易』, Classic of Changes). This study examined the historical context, personal history, and construction process of Taekpungdang at the time of its creation through his collection of writings, the Taekdanggip(澤堂集). The study also estimated the original form of Taekpungdang through field surveys and historical evidence. In addition, the architectural principles and architectural expressions inherent in the Taekpungdang were derived based on the symbolic system of "taekpungdaegwa"(澤風大過) which is Lee Sik's divination and one of the 64 trigrams in the Zhōuyì. Lee Sik, who was knowledgeable in the Zhōuyì, used divination to cope with the chaotic political situation and his own misfortunes. Accordingly, He determined the direction of his life and planned the surrounding environment, architectural structure, and form of Taekpungdang based on the rules and meanings of his divination system. He embodied the architectural space of Taekpungdang with the concept of time and space inherent in the divination of "daegwa",(大過, great exceeding). In addition, he expressed the principle of the generation of palgue,(八卦, the eight trigrams for divination) and the principle of the co-prosperity of ohaeng(五行, the five elements) through the composition of walls and windows of the house. The images of Taekpungdaegwae, which are dongyo(棟撓 wood submerged in the pond) and taekmyeolmok(澤滅木, shaking pillars), were manifested in the form of buildings. Therefore, Taekpungdang can be considered a remarkable example of a building designed through the thorough utilization of the Zhōuyì divination system.

• Journal of Preventive Medicine and Public Health
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• v.27 no.4 s.48
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• pp.747-761
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• 1994

Workers' periodic health examination is the main tools used to manage the health problems of most workers in Korea. The most common health problem found in workers' periodic health examination is liver disorder. Liver disorder is also one of the most common health problems in general population and one of the leading causes of mortality in adult population. Regulation proposed by government (No. 207, Ministry of Labor, 1992) defines the criteria for selection of workers with the liver dysfunction for further evaluative examination and the examination items used for diagnosis of the workers with liver dysfunction. This study was designed to evaluate the proficiency of each examination items presently defined in Regulation and propose the optimal examination items for detection of the liver disorders found by workers' periodic health examination. Study subjects are 186 workers with abnormal liver function tests in screening examination of workers' periodic health examination. Questionnaire survey including past history of liver disorder, drinking history, height and weight was done. Physical examination by physician, routine test items defined by Regulation (SGOT, SGPT, $\gamma$-GTP, protein, albumin, total and direct bilirubin, alkaline phosphatase, $\alpha$-feto protein, HBsAg and anti-HBs), anti-HCV antibody test and liver ultrasonography were done. Results are as follows; 1. Result of evaluative examination utilizing only the items defined in Regulation was; There were 75 workers with suspected live. disorder(40.3%), 63 with no liver dysfunction (33.9%), 13 with suspected hepatitis B(7.0%), 10 workers with hepatitis B(5.4%), 10 workers with hepatitis B carrier state(5.4%), 10 with alcoholic liver disorders(5.4%), 5 with fatty liver(2.7%). When alternative diagnostic criteria applying additional examination items (drinking history, body mass index, anti-HCV antibody and ultrasonography) diagnosability of liver disorder was increased. When all four items were included, final results were; 23 workers (17.8%) with hepatitis B (10 carriers, 13 suspects and 10 hepatitis B), 10 (5.4%) with hepatitis C(4 carriers, 5 suspects and 1 hepatitis C), 13(7.0%) with alcoholic liver disorder, 45(24.2%) with fatty liver (40 suspects, 5 fatty liver), 410%) with suspected liver disorders and 44 (23.7%) with normal liver. 2. Of examination items defined by Regulation, only SGOT, SGPT, $\gamma$-GTP and HBsAg were significantly different in abnormal rate and mean value, and all other laboratory findings did not showed significant difference between two groups. Drinking history, body mass index and anti-HCV antibody test which are the items that authors included in this study, also showed significant difference between two groups. Utilization of body mass index (BMI) for abnormal liver function group in diagnosis of fatty liver had high specificity (97.6%) but sensitivity (22.3%) was low. Therefore we suggest that SGOT, SGPT, $\gamma$-GTP, HBsAg, alcohol drinking history, BMI and anti-HCV Ab were useful for diagnosis of liver disorders among worker's periodic health examination.

• Journal of Powder Materials
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• v.25 no.3
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• pp.263-272
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• 2018

Recent developments in the field of energy harvesting technology that convert ambient energy resources into electricity enable the use of self-powered energy systems in wearable and portable electronic devices without the need for additional external power sources. In particular, piezoelectric-effect-based flexible energy harvesters have drawn much attention because they can guarantee power generation from ubiquitous mechanical and vibrational movements. In response to demand for sustainable, permanent, and remote use of real-life personal electronics, many research groups have investigated flexible piezoelectric energy harvesters (f-PEHs) that employ nanoscaled piezoelectric materials such as nanowires, nanoparticles, nanofibers, and nanotubes. In those attempts, they have proven the feasibility of energy harvesting from tiny periodic mechanical deformations and energy utilization of f-PEH in commercial electronic devices. This review paper provides a brief overview of f-PEH devices based on piezoelectric nanomaterials and summarizes the development history, output performance, and applications.

• Journal of Ocean Engineering and Technology
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• v.23 no.6
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• pp.17-22
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• 2009

This study presents an investigation of the characteristics of piezoelectric sensors whose main utilization is to measure impact pressure. The piezoelectric sensors were tested from several points of view. Their characteristics were investigated for repeatability, the effect of the diameter, temperature effect, water purity, flush mounting, and AC and DC coupling. Out of these, it was revealed that the temperature effect is very significant. The characteristics of the AC and DC coupling are also very important in understanding the time history of the impact pressure.

• Journal of Korean Institute of Industrial Engineers
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• v.32 no.4
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• pp.268-278
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• 2006

Ten years have passed since Samsung SDI and LG Electronics introduced six sigma. Six sigma spreads on the wide industry areas such as service and public sectors as well as manufacturing industry. Six sigma speaks for Korean enterprise's management innovation now. Then, can we evaluate that Korean enterprise's six sigma has settled down successfully? This study compares Korean enterprise's six sigma with those of Japanese and American enterprises in the view of leadership, project, people, and methodology. We suggest five topics for the successful settlement of six sigma in Korean enterprises; 1) Role of executives and managers should be changed more actively, 2) Strategy-connected projects should be excavated, 3) Utilization and development plan should be made for black belt and master black belt, 4) Six sigma methodology should be advanced, especially DFSS methodology, and finally 5) Several innovation methodology should be integrated.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.12
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• pp.813-819
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• 2004

This paper infers two patterns of timeout from the characteristics of TCP Reno and confirms the existence of the patterns by conducting actual experiments. All timeouts can be classified into either of these patterns by using the history of RTT value. Based on the observed patterns, the paper proposes two algorithms to improve the performance of TCP Reno. Experimental results show that, when compared with TCP Reno, the proposed algorithms improve the bandwidth utilization by 3 to 12 percent. The paper provides good examples of how timeout-based and delay-based congestion control can efficiently work together.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.430-435
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• 1997

This paper presents the material properties and production of 1400kg/$\textrm{cm}^2$ ultra high-strength concrete in consideration of the history of hydration temperature for the practical utilization. A series of laboratory tests were conducted to optimize the mix proportion and then the full-scall mock up tests were performed to investigate the practicability. The thermal sensors were installed prior to concrete casting into the walls and columns, to measure the hydration temperature during the hardening process, which is inevitable to select the most appropriate curing scheme.