• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.4
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• pp.325-330
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• 2004

Several kinds of low voltage cables have been used in nuclear power plants for the supply of electric power, supervision, and the propagation of control signals. These low voltage tables must be inspected for safe and stable operation of nuclear power plants. In particular, the degradation diagnosis to estimate the integrity of low voltage rabies has recently been emphasized according to the long use of nuclear power plants. In order to evaluate their degradation, the surrounding temperature, hardness of insulation material, elongation at breaking point (EAB), etc. have been used. However, the measurement of temperature or hardness is not useful because of the absence of quantitative criteria; the inspection of a sample requires turning off of the power plant power; and, the electrical inspection method is not sufficiently sensitive from the initial through the middle stage of degradation. In this research, based on the theory that the ultrasonic velocity changes with relation to the degradation of the material, we measured the ultrasonic velocity as low voltage cables were degraded. To this end, an ultrasonic degradation diagnosis device was developed and used to measure the ultrasonic velocity with the clothing on the cable, and it was confirmed that the ultrasonic velocity changes according to the degradation of low voltage cables. The low voltage cables used in nuclear power plants were degraded at an accelerated rate, and EAB was measured in a tensile test conducted after the measurement of ultrasonic velocity. With the increasing degradation degree, the ultrasonic velocity decreased, whose potential as a useful parameter for the quantitative degradation evaluation was thus confirmed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3544-3551
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• 2012

As Korean society is quickly aging and experiencing longer life-spans, there has been increasing interest in the quality of life of the elderly. Depression has been indicated as an significant factor in the later years of one's life. The purpose of this study is to seek ways to improve the quality of life of the elderly in senior welfare center as it examines the quality of life and the extent of depression in them. One-on-one interviews were conducted with 127 subjects from the senior welfare center from November, 2011 to January, 2012, using Korean versions of WHOQOL-BREF and the Beck Depression Inventory. Among the interviewees were 62 males and 65 females. The study showed that the quality of life measured 85.82(${\pm}16.35$) points out of 130 and the extent of depression measured 9.45(${\pm}8.02$) points. The quality of life showed significant differencies according to education, degree of health, type of health insurance, occupation, and financial independence; while the depression varied according to gender, education, degree of health, type of health insurance, occupation, means of daily living, financial independence and leisure activities. Significant correlation was shown statistically between quality of life and depression. It is recommended that local communities develop programs for the promotion of the aged health and active social participation as well as job creation for the elderly, in order to improve the quality of life.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.11
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• pp.846-850
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• 2009

Recently, wireless sensor networks have found their way into a wide variety of applications and systems with vastly varying requirements and characteristics such as environmental monitoring, smart spaces, medical applications, and precision agriculture. The sensor nodes are battery powered. Therefore, the energy is the most precious resource of a wireless sensor network since periodically replacing the battery of the nodes in large scale deployments is infeasible. Energy efficient mechanisms for gathering sensor readings are indispensable to prolong the lifetime of a sensor network as long as possible. There are two energy-efficient approaches to prolong the network lifetime in sensor networks. One is the compression scheme to reduce the size of sensor readings. When the communication conflict is occurred between two sensor nodes, the sender must try to retransmit its reading. The other is the MAC protocol to prevent the communication conflict. In this paper, we propose a novel approaches to reduce the size of the sensor readings in the MAC layer. The proposed scheme compresses sensor readings by allocating the time slots of the TDMA schedule to them dynamically. We also present a mathematical model to predict latency from collecting the sensor readings as the compression ratio is changed. In the simulation result, our proposed scheme reduces the communication cost by about 52% over the existing scheme.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.463-470
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• 1998

To improve muscle quality and prolong freshness of sashimi, the effects of freezing-thawing condition on physicochemical and rheological properties of plaice muscle were investigated. Muscle tested were frozen with quick freezing (liquid nitrogen gas) or slow freezing ($-15^{\circ}C$ air). Transition time of zone of ice crystal formation was within 10 minute for quick freezing and 110 minute for slow freezing. Time required for thawing to $0^{\circ}C$ in muscle temperature by various thawing methods was shortest with $25^{\circ}C$ tap water, followed by $15^{\circ}C$ tap water, $10^{\circ}C$ tap water, $25^{\circ}C$ air, $5^{\circ}C$ tap water and $0^{\circ}C$ cold water. Breaking strength of muscle was higher in quickly frozen sample than in slowly frozen sample. According to sashimi term, changes in breaking strength of muscle did not show any difference in quickly frozen sample, while showed significant difference in slowly frozen sample. The remaining content of ATP was not effected by freezing speed, and ATP content was apt to higher in quickly thawed sample than in slowly thawed sample. IMP was the majority of ATP and it's related compounds of sample after freezing and thawing. Collagen matrix was weakened markedly in slowly frozen sample than in quickly frozen sample.

• Journal of the Korean Institute of Intelligent Systems
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• v.27 no.1
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• pp.1-6
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• 2017

Recent researches on radio frequency energy harvesting networks(RF-EHNs) with limited energy resource like battery have been focusing on the development of a new scheme that can effectively extend the whole lifetime of a network to semipermanent. In order for considerable increase both in the amount of energy obtained from radio frequency energy harvesting and its charging effectiveness, it is very important to design a network that supports energy harvesting and data transfer simultaneously with the full consideration of various characteristics affecting the performance of a RF-EHN. In this paper, we proposes an interference-based charging aware routing protocol(ICARP) that utilizes interference information and charging time to maximize the amount of energy harvesting and to minimize the end-to-end delay from a source to the given destination node. To accomplish the research objectives, this paper gives a design of ICARP adopting new network metrics such as interference information and charging time to minimize end-to-end delay in energy harvesting wireless networks. The proposed method enables a RF-EHN to reduce the number of packet losses and retransmissions significantly for better energy consumption. Finally, simulation results show that the network performance in the aspects of packet transmission rate and end-to-end delay has enhanced with the comparison of existing routing protocols.

• Journal of Oral Medicine and Pain
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• v.34 no.2
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• pp.133-141
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• 2009

We reviewed retrospectively the medical records of 600 elderly patients, over 65 years old who visited oral medicine. The ratio of the age group was composed of 65${\sim}$74 years old group was 63.7%, 75${\sim}$84 years old group was 32.2%, over 85years old group was 4.2%, and the patients were mostly females. The main chief complaint was composed of oral soft tissue problem(44.1%) and oromaxillofacial pain(39.0%). The majority of systemic diseases was composed of diseases of the circulatory system(30.1%), diseases of the musculoskeletal system and connective tissue(16.8%), endocrine, nutritional and metabolic diseases, and diseases of the digestive system(10.1%). The numerous pateints were diagnosed as soft tissue disease(32.0%), arthrogenous disease(24.1%), and myogenous disease(18.1%) of temporomandibular disease.Principally medication(43.9%), physical therapy(24.2%) were performed. 14.2% of all patients visited oral medicine with a letter of request written by other medical departments or local dental clinics, or referred from other departments in Chosun university dental hospital. These findings indicate epidemiologic characteristics on the elderly patients visited oral medicine. We hope that this study will play a basis in the future research about the elderly patients.

• Korean Journal of Comparative Education
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• v.24 no.3
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• pp.179-198
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• 2014

The purpose of this study is to find some implications for improving diversities of the senior high school system in Korea, by examining those of Australian high school system. Based on the literature review, school diversification can be defined as providing students or their parents with some range of alternative programs from which they can choose a school or program they believe are best suitable for them. In this point, the concept is very similar to that of school choice. The finding of this study can be summarized as follows. First, the programs of within-school diversification at Australian senior secondary schools include subject selecting, extension programs and vocational education and training courses(VET). Second, selective schools, independent schools and specialist schools are the types of between-schools diversity programs in Australia. Third, the characteristic of Australian school diversification was traditionally between-schools diversification, of which the purpose is to provide excellent learning opportunities for some talented students. However, the policy trend has, recently, been extended to within-school diversity programs. The conclusions of this study are as follows. First, the policy of high school diversification 300 in Korea can be seen as a suitable one because one of its aims was to overcome some limitations of the school equalization policy. Second, well defined within-school diversity programs should be considered in order to avoid educational disadvantage issues in education that can be inevitably risen from between-school diversification policies. Lastly, the possibilities of implementing VET programs at general high schools should also be urgently considered.

• Korean Security Journal
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• no.57
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• pp.85-110
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• 2018

The bodyguard is continuously training basic physical training and security art martial to protect the privacy of security target, prepare and deal with external contingencies and threats. Currently, university students majoring in security are required to take a judo class, one of their security art martial, which can use a technology to catch, crush and repress opponent. Therefore, this study identified the effects of systematic training on body composition, Performance fitness, growth hormones, and IGF-1 among male university students through a 10-week judo training program so that it was committed to providing objective data to enhance the value of judo as a security art martial and as a result, we have a conclusion as follows: After 10 weeks of judo training, muscle mass increased significantly, and body fat rate and BMI decreased significantly. The muscular strength and power of Performance fitness were shown to increase significantly, and growth hormones were shown to increase significantly. In total, the above results showed that for judo training university students, overall body composition improved positively, the muscular strength and power of active physical fitness improved, and growth hormones increased. Thus, the increase in muscle strength and growth hormones through judo training will encourage fat breakdown due to the development of the body's muscles and increase bone density in the spine, thereby reducing the risk of fractures and preventing injury to the trainees who are performing a security art martial. It will also greatly help your health by preventing obesity, cardiovascular and metabolic diseases, which eventually will enhance your bodyguard function and prolong your life as a bodyguard.

• Food Science and Preservation
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• v.16 no.4
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• pp.518-524
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• 2009

The quality attributes of frozen dough mixed with milk proteins (casein: C and whey protein: W) and polysaccharides (sodium alginate: A and ${\kappa}-carrageenan:$ K), and with 1.6% (w/w) wheat flour, were investigated to improve the quality of dough. Addition of milk protein-polysaccharide mixtures increased water absorption, as assessed by farinography, compared with control material. Dough prepared with CA and WA mixtures showed longer development times and increased valorimeter values compared with control samples. However, addition of milk protein-polysaccharide mixtures decreased dough stability, elasticity, and strength. Gelatinization temperature and the temperature at maximum viscosity, as measured by amylography, increased on addition of milk protein-polysaccharide mixtures, but the maximum viscosity decreased compared with control samples. The control showed a lower dough volume than did dough prepared with CA and WA mixtures. These results indicate that addition of milk protein-polysaccharide mixtures, especially CA and WA, improved the quality of frozen dough,and could be useful to prevent bread becoming stale.

• Land and Housing Review
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• v.12 no.4
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• pp.103-117
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• 2021

With the current rapid changes in population and technology, the long-lastig housing certification system is a means of prolonging the physical and functional lifespan of a building. The certification requires differentiation between the structure and infill elements to allow for variability and ease of repairs. This works well with prefabricated houses so this study investigated the possibility of applying the long-lastig housing certification requirements to apartment construction using off-site construction (OSC) methods focused on the installation of bathrooms (plumbing and toilet) that differ from the traditional wet method. This study examined three different sized floor plans at 22 m², 46 m², and a combined one resulting in 69 m². The larger 69 m² plan utilized a removeable non-load bearing wall to increase flexibility in the layout of the floorplan. The apartments are constructed of steel reinforced concrete composite columns on a 9 m × 10.5 m grid with integrated slabs. The exterior and interior infill walls are all non-load bearing with some containing plumbing. This separation of the structure and infill walls can help meet some of the criteria in the long-lastig housing certification, particularly with the ease of repairs. Technologies that facilitate the replacement of infill elements that contain plumbing and other building services can benefit the nation by reducing carbon emissions and therefore tax incentives should be introduced to increase the adoption of the proposed construction methods.