• Korean Journal of Medicinal Crop Science
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• v.21 no.6
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• pp.444-454
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• 2013

The development of random amplified polymorphic DNA (RAPD) and expressed sequence tag-derived simple sequence repeats (EST-SSRs) provided a useful tool for investigating Korean ginseng genetic diversity. In this study, 18 polymorphic markers (7 RAPD and 11 EST-SSR) selected to assess the genetic diversity in 31 ginseng accessions (11 Korean ginseng cultivars and 20 breeding lines). In RAPD analysis, a total of 53 unique polymorphic bands were obtained from ginseng accessions and number of amplicons ranged from 4 to 11 with a mean of 7.5 bands. Pair-wise genetic similarity coefficient (Nei) among all pairs of ginseng accessions varied from 0.01 to 0.32, with a mean of 0.11. On the basis of the resulting data, the 31 ginseng accessions were grouped into six clusters. As a result of EST-SSR analysis, 11 EST-SSR markers detected polymorphisms among the 31 ginseng accessions and revealed 49 alleles with a mean of 4.45 alleles per primer. The polymorphism information content (PIC) value ranged from 0.06 to 0.31, with an average of 0.198. The 31 ginseng accessions were classified into five groups by cluster analysis based on Nei's genetic distances. Consequently, the results of ginseng-specific RAPD and EST-SSR markers may prove useful for the evaluation of genetic diversity and discrimination of Korean ginseng cultivars and breeding lines.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.6
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• pp.629-636
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• 1991

Yellowtail fishes(Seriola quinqueeradiata) were submitted to the storages using ice-cooling($0^{\circ}C$), partial freezing($-3^{\circ}C$) and freezing $-20^{\circ}C$) method. Changes in the structures of muscle during storage at different temperatures were investigated. The ice-cooling and partial freezing storage caused early decomposition of glycogen granules and mitochondrial inner membrane, but it was accorded to much slower manner comparing with that of ice-cooling storage. The scars of ice crystals were appeared after three days of storage. The number and size of the crystal increased as progressing of the storage. They were circular and mostly located between fibers. When using the freezing storage, glycogen granules were mostly found from the muscle cell even after fourteen days of storage. Mitochonidral inner membrane maintained their integrity. The scars of ice crystals were also found, however, different from those of partial freezing storage. Their existing sites were random and their shapes were irregular. In many cases, they located in the fiber and had keen edges. Fibers were broken mostly at the Z-lines on fourteen days of storage. From these results, it was concluded that partial freezing storage can repress autolytic enzymic action and can reduce the physical damage from ice crystals which is caused by freezing.

• Journal of the Korean Data and Information Science Society
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• v.27 no.5
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• pp.1375-1387
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• 2016

The purpose of this study was to evaluate the effect of exercise on cognitive function in the elderly through a systematic literature review and meta-analysis. For the study purpose, 14 studies were selected through a systematic process of using several databases and 11 studies were used to estimate the effect size of exercise on cognitive function. Meta-analysis was performed using a random effects model, and the effect size on cognitive function was calculated. The effect size for cognitive function of exercise intervention was Hedges' g=1.05 (95% CI: 0.61~1.50), indicating a large effect size. For heterogeneity, moderator analysis was performed using intervention, number of times per week, intervention duration, and cognitive function measurement. Cognitive function measurement was statistically significant, the other moderators did not significant difference. Results support that exercise has significant positive effects on cognitive function in elderly in korea. It also provided a basis that can be applied to exercise intervention design for cognitive function.

• Korean Journal of Social Welfare
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• v.65 no.1
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• pp.227-245
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• 2013

This study used the third wave of individual data of KReIs(Korean Retirement and Income Study) because the third wave of data only had the necessary variables which fit into this study. The data was collected in 2010 using national random sampling. The target population was adults who are older than 65 and the sample size of this study was 4,080. The factors of successful aging were compared by the recognition of old age (group (1): people who recognize they are not older adults(n=620); group (2): people who recognize they are older adults(n=3,460)). For comparison of each variable by the recognition of old age, t-test, chi-square test and ANCOVA were used depending on the types of variables. To test the effect on the life satisfaction of the factors of successful aging, hierarchical regressions were used for each group. 1) Except for the number of leisure activities, older adults who recognized they were not old(group (1)) had a higher level of factors composing of successful aging than older adults who recognized they were old(group (2)). 2) For group (1), age did not affect their life satisfaction in a statistically significant level, but for group (2) age negatively affected their life satisfaction. 3) The results indicated that cognitive and physical functioning were more important than avoiding disease and disability. 4) For group (2), IADL affected life satisfaction positively in a statistically significant level, but for group (1), IADL did not affect life satisfaction. 5) For group(2), whether they had a job or not affected the life satisfaction differently.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.6 no.1
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• pp.23-37
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• 2011

This paper is brought to carry out an empirical study whether evolution process of venture firm's scale is following the Gibrat's law; random evolution process, or Pareto law; self-organizing process. The empirical test, as attaching theoretical explanation, of this research utilize the serial data samples of 92 KOSDAQ listed companies from the year of 2005 through 2008. Summarizing the research results are as followed. First, Gini Coefficients representing the density of venture firm's scale has been constantly reduced since the year of 2005 in terms of number of employee, while these index increased during the same time period from the perspective of sales volume. Second, the evolution process of Korea venture firm's scale is following the Power Law related to Pareto Law. In particular, estimated Pareto coefficient, ${\alpha}$, is shown lower than 1 which is significant result. Third, the probability of joining in the top tier group of firm starting from the early stage growing is forecasted into 6.9%, the result which emphasize the starting scale of venture firm play an important role in long term evolution of venture firm.

• Composites Research
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• v.29 no.1
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• pp.1-6
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• 2016

Low-speed impact was localized on a stiffened composite structure, using 4 FBG sensors with 100 kHz-sampling rate interrogator and devised localization algorithm. The composite specimen consists of a main spar and several stringers, and the overall size of the specimen's surface is about $0.8{\times}1.2m$. Pre-stored reference data for 247 grid locations and 36 stiffener locations are gathered and used as comparison target for a random impact signal. The proposed algorithm uses the normalized cross-correlation method to compare the similarities of the two signals; the correlation results for each sensor's signal are multiplied by others, enabling mutual compensation. 20 verification points were successfully localized with a maximum error of 43.4 mm and an average error of 17.0 mm. For the same experimental setup, the performance of the proposed method is evaluated by reducing the number of sensors. It is revealed that the mutual compensation between the sensors is most effective in the case of a two sensor combination. For the sensor combination of FBG #1 and #2, the maximum localization error was 42.5 mm, with average error of 17.4 mm.

• Investigative Magnetic Resonance Imaging
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• v.2 no.1
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• pp.67-72
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• 1998

The mapping of the spin-spin relaxation time T2 in pixel-by-pixel was suggested as a quantitative diagnostic tool in medicine. although the CPMG pulse sequence has been known to be the best pulse sequence for T2 measurement in physics NMR, the supplied pulse sequence by the manufacture of MRI system was able to obtain the maximum of 4 CPMG images. Eight or more images with different echo time TEs are required to construct a reliable T2 map, so that two or more acquisitions were required, which easily took more than 10 minutes. 4-echo CPMG imaging pulse sequence was modified to generate the maximum of 8 MR images with evenly spaced echo time TEs. In human MR imaging, since patients tend to move at least several pixels between the different acquisitions, 8-echo CPMG imaging sequence reduces the acquisition time and may remove any mis-regitration of each pixels signal for the fitting of T2. The resultant T2 maps using the theoretically simulated images and using the MR images of the human brain suggested that 8 echo CPMG sequence with short echo spacing such as 17-20 msec can give the reliable T2 map.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.5
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• pp.1-6
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• 2007

In wireless mesh networks (WMNs), the end-to-end throughput of a flow decreases drastically according to the traversed number of hops due to interference among different hops of the same flow in addition to interference between hops of different flows with different paths. This paper proposes a distributed multi-channel assignment scheme based on hops (DMASH) to improve the performance of a static WMN. The proposed DMASH is a novel distributed multi-channel assignment scheme based on hops to enhance the end-to-end throughput by reducing interference between channels when transmitting packets in the IEEE 802.11 based multi-interface environments. The DMASH assigns a channel group to each hop, which has no interference between adjacent hops from a gateway in channel assignment phase, then each node selects its channel randomly among the channel group. Since the DMASH is a distributed scheme with unmanaged and auto-configuration of channel assignment, it has a less overhead and implementation complexity in algorithm than centralized multi-channel assignment schemes. Simulation results using the NS-2 showed that the DMASH could improve remarkably the total network throughput in multi-hop environments, comparing with a random channel assignment scheme.

• Journal of architectural history
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• v.3 no.1
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• pp.101-122
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• 1994

This paper is one of the sequels from 'A Survey of Villages and Dwellings of Korean Immigrants in the North-Eastern Part of China'. It is the result of the extensive survey of Ch'ang-ts'ai-tsun village and covers several architectural characteristics of the dwellings. This paper alma to identify the 'double file' dwelling type, which is believed as one of the main stream of Korean folk dwelling. In this type, 'Chung-ju-kan' forms the central open space, where main household functions are carried out. This type originates from climatic reasons and functional reasons as well. This paper also aims to clarify how the dwelling forms are changed according to the life styles of various periods. The Korean immigrants in this village have experienced rapid changes in modern times like other Chinese. Through various political movements, the original dwelling type of this village has changed to adapt various needs and functions, which shows the simple truth : dwelling form changes according to the changes of life style and social structure. In this paper the directions of chimney through various periods are analyzed to verify the differences of the house layout methods and concepts of the time. The village had grown through 3 main periods before liberation period(1946), communization period(1946 - 1966) and contemporary period (1967 - ). It is concluded as follows: 1. The village was originated in late 19th century along the east-west street, which was a major routes of Korean Immigrants to China. In this area there was no regularity in its site plan. The direction of chimney, which was usually westward, was not determined according to the location of gate. This type was kept until liberization of this area, 1946. The plans of dwellings followed Ham-kyong-do 'double file' dwelling type, '6-kan dwelling' or '8-kan dwelling'. 2. The 'New Village' area, which was formed in the communization period, has a strict regularity in its site plan. The direction of chimney was determined as opposite direction of the gate. This method was maintained until 1976, when Mao died and new 'open' policy was held by Chinese government. In this area the 'dwelling house' plan type was not changed, but its layout and size were restricted. The general form of the dwelling in this village was shaped in this period. 3. The contemporary dwellings were built in random site location. The dwelling type was changed because of the reduction of family size and the permissin of private ownership. The number of rooms was reduced but the storage rooms and domestic animal hutches were added. But the 'Chung-ju-kan', the major chacteristics of north-eastern Korea dwelling is still kept. It becomes one large 'Chtin-ju-kan' room like 'open plan' type.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.3
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• pp.156-162
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• 2010

When eccentric or inclined load acts on foundation of the port & harbor structures, partial safety factors of bearing capacity limit state were estimated using reliability analysis. Current Korean technical standards of port and harbor structures recommend to estimate the geotechnical bearing capacity using the simplified Bishop method. In practice, however, simple method of comparing ground reaction resistance with allowable bearing capacity has been mostly used by design engineers. While the simple method gives just one number fixed but somewhat convenient, it could not consider the uncertainty of soil properties depending on site by site. Thus, in this paper, partial safety factors for each design variable were determined so that designers do perform reliability-based level 1 design for bearing capacity limit state. For these, reliability index and their sensitivities were gained throughout the first order reliability method(FORM), and the variability of the random variables was also considered. In order to verify partial safety factors determined here, a comparison with foreign design codes was carried out and were found to be reasonable in practical design.