• Physical Therapy Korea
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• v.6 no.2
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• pp.16-31
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• 1999

The purpose of this study was to assess the fatigue in lumbar and abdominal muscles in patients with chronic low back pain compared with normal subjects using spectral analysis with mean power frequency and median power frequency. The experimental group consisted of twenty subjects who had experienced chronic low back pain for over one year after the onset day. A control group consisted of twenty normal subjects with no history of low back pain. All subjects stood in an apparatus to perform sustained contraction in the lumbar and abdominal muscles for 30 seconds with 60% maximal voluntary isometric contraction (MVIC). The resulting electromyographic (EMG) recorded time serial data were transformed into frequency serial data by Fast Fourier Transformation (FFT). The results were as follows: 1) lumbar muscles measured, the frequency change ratio of both median power frequency and mean power frequency was significantly greater for experimental group compared with control group group (p<0.05). In measured two abdominal muscles (inferior rectus abdominis, obliquus externus abdominis) except superior rectus abdominis, the frequency change ratio of both median power frequency and mean power frequency was significantly greater for experimental group compared with control group (p<0.05). 2) In all three (longissimus thoracis, iliocostalis lumborum, multifidus) lumbar muscles measured, the initial frequency value of both median power frequency and mean power frequency was significantly lower for the experimental group compared with the control group (p<0.05). In the two (inferior rectus abdominis, obliquus externus abdominis) abdominal muscles measured (superior rectus abdominis not included), the initial frequency value of both median power frequency and mean power frequency was significantly lower for the experimental group compared with the control group (p<0.05). These results suggest that in patients with chronic low back pain there is a trend for more fatigue to occur in both lumbar and abdominal muscles than in the normal control group. This would seem to suggest that in treatment programs for patients with chronic low back pain, improvement of endurance in all trunk muscles should be considered.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.1
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• pp.67-79
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• 1995

Temporal variation of demersal fish in Asan Bay was determined by analyzing seasonal samples collected by an otter tyawl from November 1990 to August 1993. Of 49 species identified, Cynogiossus joyneri, Thrissa koreans and Johnius belengerii predominated in abundance, consisting of $84.7\%$ in fish numbers and $70.5\%$ in biomass. The number of species did not show any significant seasonal variation. Fish numbers and biomass were comparatively high 3n spring, summer and tall, and low in winter. Community structure, analyzed by principal component analysis using rank correlation, showed a clear seasonal trend, which seems to be related to the seasonal effects such as temperature. The number of species and their abundance in the study area were lower than those in other embayments of Korean peninsula. It seems that unstability of the sediments by tidal mixing caused this phenomenon. The total number of species decreased annually. The species of which the frequency of occurrence tends to diminish as time were mainly composed of the species which rarely occurred with low abundance.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.3
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• pp.189-201
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• 2013

To study characteristics of the water quality in the Hansan-Geoje bay, we analyzed the long term monitoring data collected at the two sites during the period of 1987~2010. The trophic state of the waters in Hansan-Geoje bay was the mesotrophic level by the classification of Wasmud et al.[2001]. The water nutrients increased steadily from a wet season (Aug.), it reached the maximum concentration peak in a dry season (Nov.), and then decreased steadily to the winter, it reached at the minimum value in May in the next year. The result of factor analysis divided the waters of Hansan-Geoje bay into the five factors (nutrient, season, inflow land water, pollution, internal production) and the factors represented the 76.82% on the status of the waters. According to time series analysis, temperature, DO and bottom DIP were increased, and pH and COD were decreased during the period of 1987~2010. In particular, the fluctuation trend of DIN has been turned from oversupply to shortage by the N/P ratio since before and after 1990's. The water quality of the Hansan-Geoje bay has been recovered except DIP since 1987, despite of its geographical characteristic which is a general semi-closesd bay and a massive aqua-culture ground. To preserve the waters in Hansan-Geoje bay, we need to know on the cause of the increase or accumulation of DIP, and we should continue to study on the interrelation between the aqua-culture and water environment.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.5
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• pp.372-379
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• 2017

Software reliability factor during the software development process is elementary. Case of the infinite failure NHPP for identifying software failure, the occurrence rates per fault (hazard function) have the characteristic point that is constant, increases and decreases. In this paper, we propose a reliability model using the chi - square distribution which depends on the degree of freedom that represents the application efficiency of software reliability. Algorithm to estimate the parameters used to the maximum likelihood estimator and bisection method, a model selection based on the mean square error (MSE) and coefficient of determination($R^2$), for the sake of the efficient model, were employed. For the reliability model using the proposed degree of freedom of the chi - square distribution, the failure analysis using the actual failure interval data was applied. Fault data analysis is compared with the intensity function using the degree of freedom of the chi - square distribution. For the insurance about the reliability of a data, the Laplace trend test was employed. In this study, the chi-square distribution model depends on the degree of freedom, is also efficient about reliability because have the coefficient of determination is 90% or more, in the ground of the basic model, can used as a applied model. From this paper, the software development designer must be applied life distribution by the applied basic knowledge of the software to confirm failure modes which may be applied.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.4
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• pp.355-360
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• 2010

Purpose: Analysis performance for spectacle lens which sales in domestic market and optimization design a spectacle lens which is corrected aberration. Methods: Measured center thickness, radius and aspherical surface coefficient for spherical and aspherical lenses which were ${\pm}$5.00D. Refractive index for every lens was 1.6 and they came from 4 different companies. I used 3 types of equipment to measure lenses. ID-F150 (Mitutoyo) : Center Thickness, FOCOVISION (SR-2, Automation Robotics) : Radius, PGI 1240S (Taylor Hobson) : Aspherical surface coefficient. Designed a lens which had 27 mm of distance from lens rear surface to center of eye, 4 mm of pupil diameter and small aberration on center vision $30^{\circ}C$. To shorten axial distance compared with the measured lens rise merits for cosmetic. Lens Design tool was CODE V (Optical Research Associates). Results: -5.00D aspherical lens had somewhat high astigmatism and distortion compared with the spherical lens. But it had a merit for cosmetic because of short axial height and decrease edge thickness. Improved a performance of distortion and ascertain merits for cosmetic due to short axial height and decrease edge thickness same as (-) lens in case of +5.00 aspherical lens. Though an optimization process front surface aspherical lens had a good performance for astigmatism and distortion and the merit for beauty compared with measured spherical lens. Conclusions: Design trend for domestic aspherical lens is decrease axial height and thickness to increase a merit for cosmetic not but increase performance of aberration. From design theory for optimization design front surface aspherical spectacle lens which has improved performance of aberration and merit for cosmetic at the same time compared with the measured lens. Expect an improved performance from design back aspherical lens compared with front aspherical lens.

• Journal of Distribution Science
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• v.11 no.2
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• pp.45-55
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• 2013

Purpose - The development and implementation of OSS (Open Source Software) led to a dramatic change in corporate IT infrastructure, from system server to smart phone, because the performance, reliability, and security functions of OSS are comparable to those of commercial software. Today, OSS has become an indispensable tool to cope with the competitive business environment and the constantly-evolving IT environment. However, the use of OSS is insufficient in small and medium-sized companies and software houses. This study examines the need for OSS Intermediaries in the Software Distribution Channel. It is expected that the role of the OSS Intermediary will be reduced with the improvement of the distribution process. The purpose of this research is to prove that OSS Intermediaries increase the efficiency of the software distribution market. Research design, Data, and Methodology - This study presents the analysis of data gathered online to determine the extent of the impact of the intermediaries on the OSS market. Data was collected using an online survey, conducted by building a personal search robot (web crawler). The survey period lasted 9 days during which a total of 233,021 data points were gathered from sourceforge.net and Apple's App store, the two most popular software intermediaries in the world. The data collected was analyzed using Google's Motion Chart. Results - The study found that, beginning 2006, the production of OSS in the Sourceforge.net increased rapidly across the board, but in the second half of 2009, it dropped sharply. There are many events that can explain this causality; however, we found an appropriate event to explain the effect. It was seen that during the same period of time, the monthly production of OSS in the App store was increasing quickly. The App store showed a contrasting trend to software production. Our follow-up analysis suggests that appropriate intermediaries like App store can enlarge the OSS market. The increase was caused by the appearance of B2C software intermediaries like App store. The results imply that OSS intermediaries can accelerate OSS software distribution, while development of a better online market is critical for corporate users. Conclusion - In this study, we analyzed 233,021 data points on the online software marketplace at Sourceforge.net. It indicates that OSS Intermediaries are needed in the software distribution market for its vitality. It is also critical that OSS intermediaries should satisfy certain qualifications to play a key role as market makers. This study has several interesting implications. One implication of this research is that the OSS intermediary should make an effort to create a complementary relationship between OSS and Proprietary Software. The second implication is that the OSS intermediary must possess a business model that shares the benefits with all the participants (developer, intermediary, and users).The third implication is that the intermediary provides an OSS of high quality like proprietary software with a high level of complexity. Thus, it is worthwhile to examine this study, which proves that the open source software intermediaries are essential in the software distribution channel.

• Korean Journal of Construction Engineering and Management
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• v.16 no.5
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• pp.97-104
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• 2015

Apartment Housing 25 in the field of construction since 2000 collected by types of labor: reinforced concrete, plaster, internal, equipment, electrics communication, the other work. And the performance of labor input was collected in the amount of construction work performed on a monthly basis. After changing the construction period in the standardization work that is 100% of the construction period, the amount was converted into labor ratio by type. Analysis of the input flow rate and the amount of labor conclusions were as follows: (1) The size of the labor rate is reinforced concrete work (38.25%), plastering work (5.10%), internal work (5.67%), equipment work (9.10%), electrics communication (8.76%), the other works (33.12%) and the size of labor rate is the largest work in reinforced concrete work. (2) The peak of labor input ratio was from 52.5% month to 62.5% month. This was when the labor rate of 3.6%. (3) The period month of the largest labor ratio% is 35% month by reinforced concrete construction, and this time it was 2.12% per month labor rate, and reinforced concrete construction is finishing from 65% month to 80% month. This showed the greatest congestion of mutual interference between each works is being continue. The results of this study are the greatest congestion in apartment housing construction has informed the high period(%months), which is essential to a successful project.

• Korean Journal of Construction Engineering and Management
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• v.14 no.1
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• pp.3-11
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• 2013

As construction projects became larger and longer, the need for the construction technologies and innovative construction processes has been continuously increased in construction field. In response to this trend, construction industries tried to adopt the concurrent engineering which had been normally applied for manufacturing industries to develop the products with improved quality in a reduced time. However, the application of the concurrent engineering to construction field was limited due to the lack of advanced management system and incomplete theoretical backgrounds. In this regard, this study attempted to develop a checklist for the successful application of concurrent engineering to bridge projects. To this end, this study presents the checklist for the application of concurrent engineering to construction projects. Further, the checklist was modified and updated to reflect the specific feature of the bridge construction using expert interviews. With the help of additional 188 experts, a questionnaire-based survey was also conducted to validate the checklist. In addition, using importance-performance analysis(IPA), the study identified the factors needed for intensive improvement. Consequently, the proposed checklist is expected to be useful, because it improves the applicability of the concurrent engineering in that it enables managers to monitor construction progress and further to protect the project from potential risks.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.3
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• pp.121-131
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• 2012

The social welfare service is expanding to different field as the social welfare budget is increasing. By this opportunity, it needs to make clear of the basis of argument that the necessity of development of Korean government's support and aid by social policy should be worked. This research dealt with the national economic effect in relation to welfare for the disabled in terms of welfare economics. Budget spending for the achievement of welfare for the disabled makes an enterprise or a person spend money continually either in a direct or indirect way. This study shows by the use of analysing the related production effects, as an economical influence of welfare for the disabled budget assuming by means of measuring. The results are analyzed that the production of one trillion and three hundred billon won is annually caused and 8,015.9 hundred million won of the direct and indirect added value is caused by the welfare of the disabled budget expenditure of three local governments of capital area. And it is also assumed it creates employment cause personnel (17.673.2 person) and job cause members (26.825.2). The result of the study anticipates the role of basic research material for the necessity of intervention, support, and aid by the government and local government revised policy for the disabled welfare field at this point in time where the welfare budget policy in terms of universal social service is reinforced, rather than the trend, until recently, of realizing the social welfare budget as consumption expenditure and the function of performing the effect and evaluation in tentative action of social conflict.

• Korean Journal of Agricultural Science
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• v.47 no.1
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• pp.139-161
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• 2020

The aims of this study were to classify the cultivation status of medicinal crop farmers and to obtain basic data on domestic medicinal crops. To this end, 406 medicinal crop farmers participating in farming education programs in 14 cities and counties were surveyed over 10 months. The results were as follows. First, the biggest difficulty farmers faced in the overall production of medicinal crops was a lack of cultivation skills. Second, in a detailed inquiry about each difficulty item, the most difficult problems were injury by continuous cropping of root-using crops, shortage of specific farm machinery, uncertain market prices, and lack of knowledge about pest control or the positive list system (PLS). Third, the profitability of medicinal crops increased with career experience. Among the farmers who earned profits, requests for education and technical guidance were the most important factors for profitability. Fourth, the results of the analysis suggest that to achieve stable cultivation of medicinal crops, the following items need to be addressed: development and supply of basic cultivation technologies, climate response, registration of pest control pesticides, a solution to the injury by continuous cropping, and contracting cultivation expansion. Additionally, to improve profitability, it is necessary to create conditions that enable the same crops to grow for a long time in one region.