• Journal of the Korean Geosynthetics Society
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• v.9 no.1
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• pp.47-57
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• 2010

Granular soils having a large particle size have been used as a filling material in the construction of foundation, harbor, dam, and so on. Consequently, the shear behavior of this granular soil plays a key role in respect of stability of structures. For example, soil particle crushing occurring at the interface between structure and soil and/or within soil mass can cause a disturbance of ground characteristics and consequently induce issues in respect of stability of structures. In order to investigate the shear behavior according to an existence and nonexistence of particle crushing, numerical analyses were conducted by using the DEM (Discrete Element Method)-based software program PFC2D (Particle Flow Code). By dividing soil particle bonding model into crushing model and noncrushing model, total four particle bonding models were simulated and their results were compared. Noncrushing model included one ball model and clump model, and crushing model included cluster model and Lobo-crushing model. The combinations of soil particle followed the research results of Lobo-Guerrero and Vallejo (2005) which were composed of eight circles. The results showed that the friction angle was in order of clump model > cluster model > one ball model. The particle bonding model compared to one ball model and noncrushing model compared to crushing model showed higher shear strength. It was also concluded that the model suggested by Lobo-Guerrero and Vallejo (2005) is not appropriate to simulate the soil particle crushing.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.10
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• pp.1089-1097
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• 2002

In this paper, the novel shipboard Active Phased Array Antenna(APAA) system for maritime mobile satellite communications is introduced. The antenna uses novel technologies like wide range hybrid tracking, single antenna elements with both of Rx and Tx, asymmetrical array structure, interference isolation between Rx and Tx, and error correction method from frequency scan effect. The antenna has single aperture for both of Rx and Tx with 32 $\times$ 4 two-dimensional array. The antenna has two beams. Its frequencies are 7.25 ~ 7.75 GHz for Rx and 7.9 ~ 8.4 GHz for Tx. The antenna gains are 35.4 dBi for Rx and 35.7 dBi for Tx, those are 54 % of efficiency. The electrically steering ranges are $\pm$35$^{\circ}$ of elevation direction and $\pm$4$^{\circ}$ of azimuth direction. The mechanical control ranges at hybrid tracking capability are continuous 360$^{\circ}$ of azimuth direction and $\pm$10$^{\circ}$ of elevation direction. The antenna has 2.2$^{\circ}$ of 3 dB beamwidth, -14 dB of sidelobe level, and 21 dB of cross-pol suppression. The antenna performance was measured by near field measurement set. Its system performance was tested on the ship motion simulator and with the satellite transponder simulator. The test result showed that its tracking error was within -3 dB from its peak gain under motion condition. The antenna system was tested by real modulated Direct Broadcasting Satellite(DBS) signals to check its communication processing function.

• Journal of Ginseng Research
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• v.20 no.4
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• pp.472-500
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• 1996

Researches on mineral nutrition, physiology and phyrsiological diseases, . cultivaction methods. brceding. pest control quality management and extension during 1976-1995 in Korea were reviewed Review in brceding and pest control was restricted to the researches directely related to cultivaction. Mineral nulrient up take. partion and varicos factors such as top dreasing. Light intersity etc. and interrelationship between minerals were investigated. Top dressing was not effective due to low minera1 requorement Physiological characteristics on tempelature light and water were well elucidated and applied to assess traditional cultivation method and its inovation. Photosyrnthetic pigments. light harvest proteins and activity of related enzymes were studied. In nitrogen metabolism arginine, praline, ammonium, threonine appeared to have important role in re growth of shoot Saponin metabolism was studied in relation to growth and new ginsenosides were found but physiological role of saponin was not clearly elucidated yet Endogenous growth regulators were reported and various erogenous growth regulators were studied for growth stimulation. short stem and seed pruning etc. Various physiological diseases were investigated for cause and control measures were established. Water culture was little studied Forest culture was studied but not retched the recommendable stage Drip irrigation straw mulching. seasonal shading and soil preparation method including soil fertility adjustment were established for practical application. Shading materials completely changed to polyethylene net and materials of polymers The research on ginseng cultivation in paddy field opened the way to establish the permanent ginseng cultivation plantation Ginseng harvester and seeder were developed in the late 1950s. Transplanted and many other machines were developed in the early 1990s. In ginseng breeding only pure line selection was of practical significance several verities were at the stage of seed propagation at ginseng plantations. Mutation breeding (${\gamma}$-ray. X-ray chemicals) was not successful. The research on plantlet formation through tissue culture was a little progressed but still far behind to vegetative propagation. Disease control research was concentrated in the isolation and identification of pathogans. their ecological charactelistics and biological control and soil humigation. Potato root rot nematodes was found and control method was established. Insect and small animal control research was greatly progresses in identification, ecological investigation, and ecological and physical control. Weed control was less important due to the development of mulching method of ridge and ditch. Quality factors of raw ginseng in relation to red ginseng process were extensively studied. Traditional quality measures were elucidated in accordance with modern analytical chemistry resulting in the importance of peptides in the centrat part rather than ginsenosides For large root production growth promoting rootzone micrcorganisms (PGPRM) were isolated and active compounds were identified. Field test on PGPRM was on going. Varictus methods formality improvement through cultivation were developed. Management research of ginseng production was rare Extension was active throuch official and private organizations and through workshop for the extension specialists, and direct lectures to grower's. Extension services made the researcher to understand the existing problems at grower's fields. Research environment for ginseng production was in prime time only for three years when Korea Ginseng Research Institute was established then gradually aggravated.

• Food Science and Preservation
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• v.12 no.1
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• pp.8-16
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• 2005

To develop natural antimicrobial agents for extending the self-life of Kimchi, the effect of botanical antimicrobial agent-citrus products(BAAC) on microorganisms related to Kimchi spoilage was investigated. The inhibitory effect of BAAC on microorganisms related to Kimchi spoilage was increased according to the concentration of BAAC. Antimicrobial activities of BAAC against microoiganisms related to Kimchi spoilage were remarkably high. The effect of BAAC on the cellular membrane function of microorganisms showed the perturbation of cells in the presence of BAAC. Direct isualization of microbial cells by using both transmission md scanning electron microscope showed microbial cell membrane was destroyed by treating with BAAC. It could be confirmed that BAAC completely inhibit the growth of the test strains. The pH of BAAC-added Kimchi was a little higher than that of the control through the fermentation period. Titratable acidify, vitamin C and viable cells in BAAC-added Kimchi were changed more slowly than those in the control. Sensory evaluation did not show any significant difference between $0.01\%$ BAAC-added Kimchi and the control that showed the best palatabilities during fermentation.

• The Journal of Korean Physical Therapy
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• v.12 no.2
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• pp.121-132
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• 2000

This study was carried out to determine the influencing of electrical stimulation to cervicothoracic sympathetic ganglion(CTSG; stellate ganglion) u the sympathetic tone. For the purpose of this study. the stimulation was given to both the interferential current stimulation(ICS: AMF 100Hz) group consisting of 10 person(males 8, females 2) and the transcutaneous nerve electrical stimulation(TENS: 100 Hz) group of 10(males 7, females 3) in the right side of the trachea with probe electrodes. Then. the temperature changes on the surfaces of the forehead. cheek, neck and internal ear of cephalocervix, which is subject to the influence of the cervicothoracic sympathetic ganglion, and the palm. which is the end of the upper limbs. measured before. immediately alter. 10 minutes after and 20 minutes after experiment. The results are summarized as follows. 1. The emergence of remarkable Horner's symptoms which appear due to the changes of the tone of cervicothoracic sympathetic ganglion was not seen. However, in the interferential current stimulation group there were two felt the sense of warmth in the facial region and one person who felt it in the upper limbs, and in the transcutaneous nerve electrical stimulation group there was each one person who felt the sense of warmth in the facial region and in the upper limbs, respectively. Both groups have each one person who felt the sense of oppression in the eyelids. Three persons of the interferential current stimulation group and two persons of the transcutaneous nerve electrical stimulation group have the sense of hoarse voice or numbness in the neck. These are the symptoms that appeared during stimulation, so it is difficult for them to be considered as the direct effects of the changes of the tone of cervicothoracic sympathetic ganglion. 2. The t-test was performed to determine the significance between the right, which is the experimental side, and the left, which is the non-experimental side. Significance between the right, which is the experimental side, and the left, which is the non-experimental side. Significant changes were seen in the necks of the interferential current stimulation group and in the cheeks and internal ears of the transcutaneous nerve electrical stimulation immediately after experiment(P<.05). And the interferential current stimulation group showed a very high significance in the cheeks immediately after experiment and in the necks ten minutes after experiment(p<.01). Therefore, it could be seen that the electrical stimulation had an influencing on the changes of body temperature of the cephalocervix. 3. In both the interferential current stimulation group and the transcutaneous nerve electrical stimulation group, the forecheads, checks and necks of the cephalocervix in the experimental side(right) rather than the non-experimental side(left) had mostly a statistically significant rise in temperature immediately after experiment. The one-way ANOVA was carried out to determine the temperature change of on the surface of the body with the lapse of time; before, immediately after, ten minutes after and tewenty minutes after experiment. But no statistical significance was found from both the right and left sides.

• Management & Information Systems Review
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• v.34 no.3
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• pp.101-123
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• 2015

Amidst the growing uncertainty in external environments, securing and retaining superior human resources is becoming emphasized as a key means for organizations to achieve competitive advantages. Particularly, star employees-human resources that are characterized by their ability to create extraordinary performance relative to other peers-are increasingly gaining attention in both academia and industry because of its importance in knowledge-based industries. However, despite the prevailing recognition for star employees, few previous literature have attempted to empirically test the direct relationship between the ratio of star employees in an organization and organizational performance. Considering both the potential for positive and negative influence of star employees on organizations, the relationship between the ratio of star employees and organizational performance can not only be a simple linear relationship but can also exist in a curvilinear form. Building on the existing literature on star employees, this paper establishes competing hypotheses for the two possibilities of curvilinear relationship; as the ratio of star employees increases, marginal effects can either increase (i.e., U-shaped curvilinear relationship) or decrease (i.e., inverted U-shaped curvilinear relationship). Employing an unbalanced panel data of 35 Korean brokerage firms between years 2008 and 2013 with 134 observations, the relationship between the ratio of best analysts (i.e. star employees) as selected by Maeil Business Newspaper and financial performance (i.e. organizational performance) of corresponding brokerage firms is examined. Empirical results indicate that while organizational performance increases as the ratio of star employees increases, its positive effect diminishes over time which provides support for the curvilinear relationship with decreasing marginal effects. Our research findings imply that star employees create value in knowledge-based industries; at the same time, implications are given as results calls for caution for excessive dependence on star employees beyond a certain level.

• Journal of the Korean Dietetic Association
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• v.10 no.2
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• pp.197-204
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• 2004

The purposes of this study was to analyze the operational difference of foodservice center for homebound elderly by the presence of the dietitian. The questionnaire was developed to measure all variables for menu management and distributed to 103 meal service centers in charge of congregate meal service program and 57 centers for home-delivered meal service program. The data of 160 centers in charge of congregate meal service and home-delivered service centers were usable for analysis. Statistical data analysis was completed using the SAS 8.1 package program for descriptive analysis and chi-square test. Only 21.9% meal service centers had dietitians, what is more, they were not professionals who did menu management but foodservice managers, volunteers, cook or social workers. The current foodservice programs for the homebound elderly were operated without professional. In the part of menu managemet, dietitians were more actively involved in menu planning in the elderly foodservice center in the presence of the dietitians. The performance level of healthcare service was not significantly different, but the nutrition education in the elderly foodservice center with the dietitians was more frequently performed than that without the dietitians(p<0.05). In the food purchasing and food production management, the significant differences were shown that in the elderly foodservice centers in the presence of the dietitians, the proportion of the contract purchasing was significantly higher than that of direct purchasing(p<0.01). In food sanitary management, the significant differences were not shown in the part of management of keeping meal for identifying the cause of food-borne illness and left-over, but the sanitation education for the foodservice employees was performed more frequently by the presence of the dietitians(p<0.01). In conclusion, the foodservice management was more systematically conducted in the elderly foodservice centers in the presence of the dietitians than that without dietitians. The elderly foodservice program has offered the health-related support for homebound elderly. Although there were several problems in elderly foodservice management, the program delivered well-targeted, effective, and efficient nutrition services and wide range of supportive service to the at-risk older population. It needs to be managed by professional for the improvement in the elderly foodservice.

• Journal of Veterinary Clinics
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• v.22 no.3
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• pp.190-193
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• 2005

The concentration of tartrate resistant acid phosphatase (TRAP) in synovial fluid of normal stifle joint was investigated in order to establish a baseline data to distinguish between healthy joint and joint with injury of cranial cruciate ligament (CCL). Twenty three mixed-breed healthy dogs free from joint diseases (fourteen adult and nine young) were used in this study. The dogs were sedated and synovial fluid was collected from the femoropatellar compartment of stifle joints by direct arthrocentesis. The concentration of TRAP in synovial fluid was determined using the method of Lang. The concentration of TRAP were $0.083{\pm}0.039$ IU/ml in adult dogs, $0.064{\pm}0.023$ IU/ml in young dogs, $0.075{\pm}0.028$ IU/ml in large dogs (>22 kg), $0.076{\pm}0.046$ IU/ml in small dogs (<22 kg), $0.085{\pm}0.036$ IU/ml in neutered dogs and $0.056{\pm}0.022$ IU/ml in intact dogs. The concentration of TRAP in the neutered dogs was significantly (p<0.05) higher than the intact dogs. This data can be used baseline data for a comparison with joint with injury of cranial cruciate ligament.

• Korean Journal of Food Science and Technology
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• v.28 no.6
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• pp.1184-1187
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• 1996

A simple and rapid detection system for $aflatoxin\;M_1\;(AFM_1)$ in cow's milk by an enzyme-linked immunosorbent assay (ELISA) was developed. Specific antibodies against $AFM_1$, conjugated to bovine serum albumin $(AFM_1-BSA)$ were raised in rabbits and purified. The cross-reactivities of the antibodies against aflatoxin analogs were less than 29.9%. When a competitive direct ELISA (cdELISA) for $AFM_1$, established by use of the antibodies was applied to the spike test of $AFM_1$ onto uncontaminated cow's milk, the assay recovery was unstable unless cow's milk was diluted to 40% (2:3) with phosphate buffered saline (PBS). In that condition of sample dilution, the mean ELISA recovery of $AFM_1$, from the cow's milk was 113% (coefficient of variation (CV) of each recovery percentage, 8.2%) in the range of $0.3{\sim}3.0\;ppb$. These results showed that the ELISA system could be a convenient tool to monitor the contamination of AFM1 more than 0.5 ppb in cow's milk (FDA allowance limit) easily.

• Land and Housing Review
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• v.2 no.1
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• pp.69-78
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• 2011

The purpose of this research is particle shape evaluation of aggregate using Digital Image Process(DIP). DIP is very useful to measure the roughness and particle shape of aggregates. Couple of aggregates, like standard sand, two different crushed stones, and two different marine aggregates, have been employed. Shape factors of two different marine aggregates are ranged 0.35 to 0.54. Crushed stone I is 0.74 which is highly flat, but standard sand is elongated shape. Especially, two marine aggregate showed a big difference of width and length which meaned a long shape. There is any significant difference of elongation ratio and flatness for each aggregate with different measuring system, like direct measurement of vernier calipers and DIP method. Shape conversion coefficient and equivalent diameter for changing 2D image to 3D image by the Digital Image Process(DIP) have been suggested and modified particle size distribution curve has been showed. The measured flatness ratios of each aggregate were 0.30, 0.36, 0.47 and 0.83, respectively. Also, the conversion shape coefficients of each aggregate were determinded as 0.77, 0.78, 0.84 and 0.92. The size of aggregate has been modified by multiplying the shape conversion coefficient and the aggregate size from DIP. The modified gradation curve with modified volume and weight of aggregate has been suggested. Within the limited test results, DIP is one of useful to get the particle shape of aggregate with limitation of measuring errors and to apply the particle distribution curve.