• Journal of Korea Port Economic Association
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• v.26 no.4
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• pp.188-206
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• 2010

Data Envelopment Analysis(DEA) is an operations research-based method for measuring the performance efficiency of decision units that are characterized by multiple inputs and outputs. DEA has been applied successfully as a performance evaluation tool in many fields. However, it has not been extensively applied in the shipbuilding industry. This paper applied the input-oriented DEA model, and Malmquist indices to the 7 shipbuilding firms to measure the efficiency and productivity changes during the period of 2004 to 2009. The Malmquist indices will be decomposed into three components such as pure efficiency change, scale efficiency change, and technical change. The empirical results show the following findings. First, the DEA findings indicate that main source of inefficiency is scale rather than pure technical. Second, the Malmquist indices show that an overall decrease in productivity.

• The Journal of Society for e-Business Studies
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• v.19 no.4
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• pp.231-249
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• 2014

We define $21^{st}$ century as an amalgamation of globalization and localization, or Glocalization. Additionally, due to the increasing supply of smart phones and wide usage of social networking services, the ability to utilize such global and regional information has increased a coperation's competitiveness in its market, and even the business models have evolved from the conventional "production and distribution" to E-commerce, through which either a direct or a non-direct transaction is possible. My hypothesis is that the ability to adapt to this trend is possible through transfer of learning, and consequently, this will have an impact on company's performance. Thus, this thesis analyzes the mid- to the long-term impact of such ability and environmental factors on the performance and technology innovation of Korean companies in China. Ultimately, this study intends to engender a basic foundation for a corporation's management strategy in China. Finally this research focuses on those Korean companies in China only and on the proof of influential factors' impact on technological innovation and technological innovation's impact on those corporations' future performances. Section I is an abstract and section II, the case examines the uniqueness and current status of Korean companies in China identifies the concept and the definition of influential factors such as education-orientation, technological innovation, and performance, and then scrutinizes each factors through a closer look at their past researches. Section III explains the thesis model, the survey's method and target, the thesis, variable factors, the content, and the method of analysis. In section IV, the thesis is proved based on the outcome of the survey. The result in Section V highlights the high comprehension of technological innovation: both education-orientation and technological innovation prove to have a positive (+) correlation with the performance. The vision on education orientation proves to have a positive (+) influence on technological innovation. The vision on education-orientation and technological innovation prove to have a positive (+) influence individually on company's performance.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.2
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• pp.153-165
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• 2014

Carbon dioxide capture and storage (CCS) technology is recognizing one of method responding the climate change with reduction of carbon dioxide in atmosphere. In Korea, due to its geological characteristics, sub-seabed geological $CO_2$ storage is regarded as more practical approach than on-land storage under the goal of its deployment. However, concerns on potential $CO_2$ leakage and relevant acidification issue in the marine environment can be an important subject in recently increasing sub-seabed geological $CO_2$ storage sites. In the present study effect data from literatures were collected in order to conduct an effect assessment of elevated $CO_2$ levels in marine environments using a species sensitivity distribution (SSD) various marine organisms such as microbe, crustacean, echinoderm, mollusc and fish. Results from literatures using domestic species were compared to those from foreign literatures to evaluate the reliability of the effect levels of each biological group and end-point. Ecological effect guidelines through estimating level of pH variation (${\delta}pH$) to adversely affect 5 and 50% of tested organisms, HC5 and HC50, were determined using SSD of marine organisms exposed to the $CO_2$-induced acidification. Estimated HC5 as ${\delta}pH$ of 0.137 can be used as only interim quality guideline possibly with adequate assessment factor. In the future, the current interim guideline as HC5 of ${\delta}pH$ in this study will look forward to compensate with supplement of ecotoxicological data reflecting various trophic levels and indigenous species.

• Restorative Dentistry and Endodontics
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• v.30 no.4
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• pp.303-311
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• 2005

The purpose of this study was to evaluate which type of Ni-Ti files are able to maintain canal configuration better in the simulated canal with abrupt curvature near it's apex. Ninety six simulated root canals were made in epoxy resin and $\sharp$15 finger spreader was used as root canal templates. The simulated root canals were made with radius of curvature of 1.5mm, 3.0mm, 4.0mm, 6.0mm respectively and the angle of curvature of all simulated canals were adjusted to 90 degree. The simulated canals were instrumented by ProFile, ProTaper, Hero 642, and $K^3$ at a 300 rpm using crown-down pressureless technique. Pre-instrumented and post-instrumented images were taken by digital camera and were superimposed with Adobe Photos hop 6.0 program. Images were compared by image analysis program. The changes of canal width at the inner and outer side of the canal curvature. canal transportation were measured at 9 measuring point with 1 mm interval. Statistical analysis among the types of Ni-Ti files was performed using Kruskal-Wallis test and Mann-Whitney U-test. The result was that ProFile maintain original canal configuration better than other engine driven Ni-Ti files in the canals above 3.0mm radius of curvature, and in the 1.5mm radius of curvature, most of Ni-Ti flies were deformed or separated during instrumentation.

• Journal of Korea Technology Innovation Society
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• v.12 no.4
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• pp.788-818
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• 2009

Renewable energy refers to solar energy, biomass energy, hydrogen energy, wind power, fuel cell, coal liquefaction and vaporization, marine energy, waste energy, and liquidity fuel made out of byproduct of geothermal heat, hydrogen and coal; it excludes energy based on coal, oil, nuclear energy and natural gas. Developed countries have recognized the importance of these energies and thus have set the mid to long term plans to develop and commercialize the technology and supported them with drastic political and financial measures. Considering the growing recognition to the field, it is necessary to analysis up-to-now achievement of the government's related projects, in the standards of type of renewable energy, management of sectional goals, and its commercialization. Korean government is chiefly following suit the USA and British policies of developing and distributing renewable energy. However, unlike Japan which is in the lead role in solar rays industry, it still lacks in state-directed support, participation of enterprises and social recognition. The research regarding renewable energy has mainly examinedthe state of supply of each technology and suitability of specific region for applying the technology. The evaluation shows that the research has been focused on supply and demand of renewable as well as general energy and solution for the enhancement of supply capacity in certain area. However, in-depth study for commercialization and the increase of capacity in industry followed by development of the technology is still inadequate. 'Cost-benefit model for each energy source' is used in analysis of technology development of renewable energy and quantitative and macro economical effects of its commercialization in order to foresee following expand in related industries and increase in added value. First, Investment on the renewable energy technology development is in direct proportion both to the product and growth, but product shows slightly higher index under the same amount of R&D investment than growth. It indicates that advance in technology greatly influences the final product, the energy growth. Moreover, while R&D investment on renewable energy product as well as the government funds included in the investment have proportionate influence on the renewable energy growth, private investment in the total amount invested has reciprocal influence. This statistic shows that research and development is mainly driven by government funds rather than private investment. Finally, while R&D investment on renewable energy growth affects proportionately, government funds and private investment shows no direct relations, which indicates that the effects of research and development on renewable energy do not affect government funds or private investment. All of the results signify that although it is important to have government policy in technology development and commercialization, private investment and active participation of enterprises are the key to the success in the industry.

• Journal of radiological science and technology
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• v.40 no.4
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• pp.581-587
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• 2017

This study was based on the data of total mineral content of about 99% at the age of 16-26 years, we aimed at female university students who are important for bone formation in their early 20s. The purpose of this study was to investigate factors of eating habits affecting their bone density and to provide data to prevent osteoporosis which might occur in the future. It was conducted on 100 female university students in their 20s, the bone mineral density according to BMI was measured by DEAX, and the analysis of 10 eating habits items and the results of BMD measurement on their own results in Excel 2010. As a result, the height was $161.08{\pm}4.70cm$, the weight was $52.43{\pm}6.43kg$, and the BMI was $20.22{\pm}2.48$, which correlated with BMD (p<0.05). According to the BMI classification, 20 had low weight and 80 had normal weight, and BMD was $0.20{\pm}0.41$ at normal weight. In the same sex, the mean T-score of the young adult group was $-0.04{\pm}0.99$ compared with the BMD of the young adult group, and the mean Z-score of the same age group was $0.02{\pm}0.93$ (p<0.001). Eating habits affecting bone mineral density were significantly affected by 3 meals per day, 1-3 cups of coffee per day and p<0.05 for Low salt formula intake. 6-9 dairy product intake was also p<0.05 but not significant. Therefore, it is considered that when 20s female students become middle-aged woman, they should have proper eating habits so that osteogenesis can be improved at young age in order to prevent bone disease.

• Korean Journal of Heritage: History & Science
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• v.53 no.2
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• pp.222-241
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• 2020

The Taereung Royal Tomb from the Joseon Dynasty is the tomb of Empress Munjeong, the second queen of King Jungjong, and it contains various types of stone artifacts. All of these stone artifacts were constructed using coarse- to medium-grained biotite granite. The major types of deterioration of the stone artifacts are identified as surface weathering and biological contaminants. Exfoliation (145 sculptures), granular decomposition (138 sculptures), and repair materials (156 sculptures), along with biological contaminant algae (154 sculptures), lichen (165 sculptures) and moss (97 sculptures), have a high occurrence frequency. In particular, it is deemed that immediate conservation treatment is required, as biological deterioration (algae) represents the most serious condition (grade 3 or higher in 94% of all stones), and it is thought that exfoliation and granulation decomposition are required for long-term conservation management. As a result of equo -tip hardness and ultrasonic measurement, more than 70% of stones were found to have very weak physical properties. Through hyperspectral analysis, organisms were shown to inhabit more than 80% of the surface of burial mound stone artifacts, and P (phosphorus), S (sulfur), Cl (chlorine), and Ca (calcium) were detected in this area. This is because Taereung Royal Tomb has been exposed to the outdoors for hundreds of years and has been weathered by physical, chemical, and biological factors. Therefore, among the stone artifacts in the Taereung Royal Tomb, those with high physical weathering grades are considered to require consolidation to reinforce them physically. Since organisms are highly likely to cause stone damage, they must be removed via dry and wet cleaning. In addition, in order to delay the reoccurrence of organisms following conservation treatment, it is necessary to regularly clean up the soil that has flowed into the burial mound, and to monitor conservation conditions over the long term.

• Journal of Life Science
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• v.17 no.5 s.85
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• pp.634-640
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• 2007

Our previous study suggested that n-3 fatty acid deficiency was associated with significantly reduced spatial learning as assessed by Morris water maze test. Here we investigated an effect of n-3 fatty acid deficiency on rat brain, retina and serum fatty acyl compositions at 15 wks age using a first generational artificial rearing technique. Newborn Rat pups were separated on day 2 and assigned to two artificial rearing groups or a dam-reared control group. Pups were hand fed artificial milk via custom-designed nursing bottles containing either 0.02%(n-3 Deficient) or 3.1% (n-3 Adequate) of total fatty acids as a-linolenic acid(LNA). At day 21, rats were weaned to either n-3 deficient or n-3 adequate pelleted diets and fatty acid compositions of brain, retina and liver were analyzed at 15 wks age. Brain docosahexaenoic acid(DHA) was lower(58% and 61%, P<0.05) in n-3 deficient in comparison to n-3 adequate and dam-reared groups, receptively, while brain docosapentaenoic acid(DPAn-6) was increased in the n-3 deficient group. In retina and serum fatty acid compositions, the decreased precentage of DHA and increased precentage of DPAn-6 were observed. These results suggested that artificial rearing method can be used to produce n-3 fatty acid deficiency in the first generation and that adequate brain DHA levels are required for optimal brain function.

• Journal of the Korean Arthroscopy Society
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• v.8 no.2
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• pp.89-93
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• 2004

Purpose: To evaluate the clinical stability and function after arthroscopic anterior cruciate ligament(ACL) reconstruction using fresh-frozen tibialis tendon allograft. Materials and Methods: Of the patients who underwent ACL reconstruction using tibialis tendon allograft from July 2002 to June 2003, thirty-one patients could be evaluated and the mean follow-up period was 19 months. Evaluations included were Lysholm knee score, 2000 International knee Documentation Committee (IKDC) subjective knee score, Lachman test, pivot shift test, KT-1000 arthrometer measurement and 2000 IKDC knee examination. Results: The mean Lysholm score was 88. Twenty-eight patients (90.3%) were good or exellent for the measured parameters. Twenty-seven patients(87.1%) was over 70 in IKDC subjective knee score. Thirty patients (96.8%) had 1+ firm end or negative Lachman test. 27 patients (87.1%) had a negative pivot shift. Thirty patients (96.8%) had less than 5mm difference of maximal manual difference by KT-1000 arthrometer. Twenty -nine patients (93.5%) were nearly normal or normal grade by 2000 IKDC knee examination. Complications were 1 case of failure and 1 case of infection. Conclusion: ACL reconstruction with the double-stranded fresh-frozen tibialis tendon allograft resulted in a reliable and predictable outcome after short-term follow-up.

• Journal of agriculture & life science
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• v.45 no.2
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• pp.125-133
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• 2011

This study was conducted on greenhouses whose side heights had been raised after the columns of 1-2W basic type greenhouses had been cut and welding with the same-sized pipes. When the wind load or snow load affects restructured pipe greenhouse like this, those parts will be structurally unsafe. To examine this, the bending strength of welded columns were measured through four stages and compared with the pipes in their original condition. Results are as follows. In the case of a bending test on welded joints about steel pipes used for greenhouses, satisfactory results couldn't be drawn because sections of both ends and the loading parts couldn't endure loads and sank regardless of loading methods. Partial problems could be solved by inserting inside pipe(steel bar) at the sections and the loading parts, but it was necessary to devise more satisfactory bending test methods. The strength of welded joints wasn't much different compared with original conditions and demonstrated only slight differences according to the sample production conditions. However, significant incompleteness in the welding process was expected to cause a decisive loss in strength. On the assumption that there were no problems in the welding process or with regard to the inclination of sub materials for columns after connection, it was deemed reasonable to assume that the strength of welded pipes was about 84~90% of the strength of the pipes in their original condition. Considering mid- and long-term strength decline following the onset of rust at joints or welding sections, structural changes in the main sub materials that are used for greenhouses at farmhouses have to be avoided to ensure structural safety, unless these changes are inevitable.