• Journal of the Korean Society of Food Culture
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• v.20 no.1
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• pp.44-52
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• 2005

This study was conducted to investigate Korean youths' use of fastfood and family restaurants in different regions, especially among cities and rural towns. Total 1,600 questionnaire surveys were distributed to Junior high and Senior high school students and 1,487 were used for the analysis. In order to consider regional differences as well as overall characteristics of youths' fastfood and family restaurant visiting behaviors, the subjects were evenly sampled from north Seoul, south Seoul, big cities, middle/small cities and small towns. As for the frequency of visiting fastfood restaurants, 58.3% of the respondents answered 'once to five times' a week. South Seoul area showed the highest frequency. 'Easiness' was the main reason of eating fastfood, which was up to 57.8% of the overall respondents while 42.8% of the small town youth ate fastfood because of the 'good taste.' As for the concepts on fastfood, 42.7% understood it as 'easy to eat' while 33.6% responded as 'easy to get fat.' For the question of getting channel of fastfood information, 44.8% answered 'TV' and 28.3% responded 'from friends.' Coupons were found to affect fastfood restaurant visits, highest in south Seoul, and lowest in small cities. For the question of the relationship of Koreanized menus and fastfood restaurant visits, small towns showed the highest frequency, while South/North Seoul had the lowest frequency. For the percentage of visiting family restaurants, respondents answered in the order of South Seoul(59.7%), North Seoul(44.5%), Big cities(39.5%), small cities(19.4%), and small towns(13.1%). Most of youth visited family restaurants because of the taste, while youths of middle/small cities visited due to the atmosphere. The effect of coupons on visiting family restaurants were found to be lower than the one of fastfood restaurants. Korean youths were found to visit fastfood restaurants very frequently in all regions and the tendency of visiting family restaurants is also increasing. At this point, balanced menus and education for healthy eating habits are urgently needed for the youth.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.4
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• pp.333-340
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• 1990

The authors carried out a visiualizational model test by the hydrogen bubble method to examine the pattern of the fluid flow besides the simple camber type and plane type otter board in circulation water channel. The experimental conditions are velocity of flow 0.05 and 0.1m/sec, angle of attack 0$^{\circ}$~45$^{\circ}$(5$^{\circ}$step). The results obtained are as follows: 1. In the case of the simple camber type otter board located angle of attack 25$^{\circ}$, vortex at the leading edge was geneated at 1/2 of chord length. 2. Size of the vortex generated in the trailing edge was about 2~3 times larger then that of the leading edge. 3. In the case of the simple camber type otter board located angle of attack 30$^{\circ}$, separation of stream-line at leading edge was generated at 1/3 of chord length. 4. Nearest stream-line in the back side of the simple camber type otter board was bent in the direction of otter board when the angle of attack was 25$^{\circ}$ and 30$^{\circ}$, and in the case of plane type otter board was expanded outside of the flow direction. 6. Area separated of the simple camber type otter board at the angle of attack 30$^{\circ}$ was smaller then that of plane type otter board. 7. Flow speed in the back side of the simple camber type otter board was about 1.4 times faster then that in the front side, and in the case of the plane otter board about 1.2 times faster.

• The Journal of Internal Korean Medicine
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• v.21 no.3
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• pp.377-388
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• 2000

Objective : This study was undertaken to evaluate the effect of Sunghyangchungisan (SHCS) on the regulation of vascular tone and $Ca^{2+}$ metabolism in arterial tissues. Vascular rings isolated from rabbit carotid artery were myographed isometrically in isolated organ baths and the effect of SHCS on contractile activities, endothelial function and $Ca^{2+}$ metabolism were determined. Methods : In phentobarbital sodium-anesthetized rabbits, SHCS administered through ear vein (100 mg/Kg body wt.) or intragastric dwelling tube (300 mg/Kg body wt.) attenuated phenylephrine (PE, 10 ${\mu}g$/Kg, i.v.)-induced increases in both systolic and diastolic cartoid arterial blood pressure. Results : In experiments with isolated arterial strips, SHCS relaxed arterial rings which were pre-contracted by phenylephrine (PE, 1 ${\mu}M$). The responses to SHCS were partially dose-dependent at concentrations lower than 0.5 mg/ml. When SHCS was applied prior to the exposure to PE, it inhibited the PE-induced contraction by a similar magnitude which was comparable to the relaxation of pre-contracted arterial rings. Washout of SHCS after observing its relaxant effect resulted in a full recovery of PE-induced contractions, indicating that the action mechanism is reversible. The observation that SHCS did not change the $ED_{50)$ of PE oh its dose-response curve ruled out the possible interaction of SHCS with ${\alpha}$-receptors. The relaxant effect of SHCS was not affected by removal of endothelium or a nitric oxide synthase inhibitor, L-NAME. Methylene blue, an inhibitor of the soluble guanylate cyclase, did not affect the relaxant effect of SHCS. These results suggest that the action of SHCS is not mediated by the endothelium nor soluble guanylate cyclase. Constant cGMP production determined in arterial strips in the presence or absence of SHCS is consistent with this conclusion. When contraction was induced by additive application of $Ca^{2+}$ in arterial rings which were pre-depolarized by high $K^+$ in a $Ca^{2+}$-free solution, the relaxant effect of SHCS was attenuated by increasing the $Ca^{2+}$ concentration. SHCS, when applied to the arterial rings pre-contracted by PE and then relaxed by nifedipine, a $Ca^{2+}$ channel blocker, did not show additive relaxation. SHCS partially blocked $Ca^{2+}$ influx stimulated by PE and high $K^+$ which was determined by 5-min ^{45}Ca$ uptake, while it did not affect $Ca^{2+}$ efflux. Conclusions : From above results, it is suggested that SHCS relax PE-induced contraction of rabbit carotid artery in an endothelium independent manner, andinhibition of $Ca^{2+}$ influx may contribute to the underling mechanism.

• Korean Journal of Remote Sensing
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• v.29 no.1
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• pp.11-20
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• 2013

Space-borne Synthetic Aperture Radar(SAR) has been one of the most effective tools for monitoring quantitative oceanographic physical parameters. The Doppler information recorded in single-channel SAR raw data can be useful in estimating moving velocity of water mass in ocean. The Doppler shift is caused by the relative motion between SAR sensor and the water mass of ocean surface. Thus, the moving velocity can be extracted by measuring the Doppler anomaly between extracted Doppler centroid and predicted Doppler centroid. The predicted Doppler centroid, defined as the Doppler centroid assuming that the target is not moving, is calculated based on the geometric parameters of a satellite, such as the satellite's orbit, look angle, and attitude with regard to the rotating Earth. While the estimated Doppler shift, corresponding to the actual Doppler centroid in the situation of real SAR data acquisition, can be extracted directly from raw SAR signal data, which usually calculated by applying the Average Cross Correlation Coefficient(ACCC). The moving velocity was further refined to obtain ocean surface current by subtracting the phase velocity of Bragg-resonant capillary waves. These methods were applied to Envisat ASAR raw data acquired in the East Sea, and the extracted ocean surface currents were compared with the current measured by HF-radar.

• Journal of Distribution Research
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• v.10 no.1
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• pp.33-57
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• 2005

After 1990's, many multi-level marketing companies lave been introduced in Korea. These MLM companies operate their stores as same way as general retailing stores. The major characteristics of these MLM companys' store is that their main customers are distributors who sell the purchased merchandise to another customers. Many studies about merchandise display in general retailing stores were reported. But, there was less research about merchandise display in these special type stores such as MLM companys' stores. This paper investigates the effects of merchandise display on distributor's merchandise selection in channel flow of multi-level marketing company. For this purpose, we formulated four hypotheses about display variance in quantity, height, location, and related merchandise to analyze the effect of merchandise display methods in MLM companys' stores. The experiment had been proceeded in three stores in a MLM company for 6 weeks and the sales data were collected by POS. The methods to analyze the data were used ANOVA and T-test. Findings of this study are as follows; First, there was no effect to store sale by the interaction effect between merchandise display method and scale of store. Second, scale of store affected considerably the volume of sales of each store according to main effect analysis. Third, display variance in quantity, height, and location did not affect store sale. In the related merchandise display, however, sale in all store was increased. Fourth, in additional analysis considering merchandise display only, display variance in both height and location affected their sale in large scale store. Based on the above results, we may predict merchandise display can affect sale in MLM companys' store as well as general retailing stores. Therefore if MLM company has large scale store, it should consider merchandise display methods in its stores.

• Journal of Distribution Research
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• v.11 no.1
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• pp.99-124
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• 2006

The purposes of the study are two-folds. First, it analyzes how factors other than price(e.g. delivery service, saving point policies, free gifts) impact total price for various products and different types of stores. Second, it analyzes how to increase market efficiencies through price level, price differences, and the frequency of price changes for different shops, various products and different types of transactions. By analyzing the price level within different types of stores, there found that prices at on-line store were lower than off-line shops. It also found price differences between pure on-line, hybrid, and off-line store. Comparing prices by product size, there found that pure on-line shops have a lower price compared to others. The results showed that on-line store had lower price variation compared to off-line shops. When comparing pure on-line store to hybrid store, hybrid store had lower price variation. In terms of the frequency of price changes, hybrid stores had higher price fluctuations. In terms of total price differences for delivery distances, pure on-line store had great price fluctuation, excluding cosmetic goods. In conclusion, if we consider price level and price fluctuations, on-line store had more efficiencies and was superior in terms of price effectiveness. Hybrid shops, on the other hand, had greater advantages for seasonal goods and dominant products. Therefore, market entry strategies should differ based on order quantity, type of store(pure on-line, hybrid, off-line), product characteristics(seasonality, product life), etc.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.6
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• pp.474-481
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• 2004

Squamous cell carcinoma is the most prevalent oral cancer, which is characterized by its low survival rate, high malignancy, mortality with facial defects, and poor prognosis. Exact cause and pathogenesis of the squamous cell carcinoma is still unknown. Various routes including smoking, radiation, and viral infections predispose its genesis, and recent studies revealed that genetic defects which fail to prevent cancer proliferation play a role. Generally, a cancer develops from the decreased rate of apoptosis which is an active and voluntary cell death, and from the altered cell cycles. Anticancer effect can be obtained by recovering the apoptotic process, and by suppressing the cell cycles. Among the apoptosis related factors, bcl-2, caspase-9, and VDAC (voltage-dependent anion channel)are produced in mitochondria of the cell. Cyclosporin-A is known to induce apoptosis through its activation with VDAC. This study was to reveal the anticancer effect of Cyclosporin A to the oral squamous cell carcinoma. The inverted microscope was used to find alterations in the tissue, and sensitivity test to the anticancer cells was performed with MTT (Tetrazolium-based colorimetric) assay. Following cell line culture of primary and metastastic oral squamous cell carcinoma, electrophoresis was performed with extracted total RNA. Finally, semi-quantitative study was carried out through RT-PCR (Reverse Transcription-Polymerase Chain Reaction). The results of this study are as follows: 1. The inverted microscopic observation revealed a poorly defined cytoplasm at $2000ng{\sim}3000ng/ml$, indistinct nucleus, and apoptosis. 2. The Growth of cancer cells was decreased at 1000ng/ml of cyclosporin-A. No cancer cell growth was observed at over 2000ng/ml concentration of cyclosporin-A, and at one week, growth of cancer cells was ceased. 3. The MTT assays were decreased as cyclosporin-A concentration was increased. This means that the activation of succinyl dehydrogenase in mitochondria was decreased following administration of cyclosporin A. 4. A result of RT-PCR showed that amount of mRNA of VDAC-2 was decreased half times at a cyclosporine-A concentration of 2000ng/ml. In bcl-2, amount of mRNA was significantly decreased 1/5 times at 2000ng/ml. caspase-9, however, showed slight increase compared to the control group. From the results obtained in this study, administration of cyclosporin-A to the cell lines of oral squamous cell carcinoma induced alterations in morphology and growth of the cells as its concentration increased. Since apoptosis related factors such as VDAS-2, bcl-2, and caspase-9 also showed distinct alterations on their mRNAs, further research on cyclosporin A as an anti-cancer agent will be feasible.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.469-478
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• 2019

Car-sharing services have been settled on as a new type of public transportation owing to their enhanced convenience, expanded awareness of practical consumption patterns, the inspiration for environmental conscientiousness, and the diffusion of smart phones following the economic crisis. With development of the market, many people have started using such services. However, security is still an issue. Damage is expected since IDs and passwords are required for log-in when renting and controlling the vehicles. The protocol suggested in this study uses bio-information, providing an optimized service, and convenient (but strong) authentication with various service-provider clouds registering car big data about users through brokers. If using the techniques suggested here, it is feasible to reduce the exposure of the bio-information, and to receive service from multiple service-provider clouds through one particular broker. In addition, the proposed protocol reduces public key operations and session key storage by 20% on mobile devices, compared to existing car-sharing platforms, and because it provides convenient, but strong, authentication (and therefore constitutes a secure channel), it is possible to proceed with secure communications. It is anticipated that the techniques suggested in this study will enhance secure communications and user convenience in the future car-sharing-service cloud environment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.4
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• pp.691-698
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• 2003

We extend the sue of the method of least square to develop a recursive algorithm for the design of adaptive transversal filters such that, given the least-square estimate of this vector of the filter at iteration n-l, we may compute the updated estimate of this vector at iteration n upon the arrival of new data. We begin the development of the RLS algorithm by reviewing some basic relations that pertain to the method of least squares. Then, by exploiting a relation in matrix algebra known as the matrix inversion lemma, we develop the RLS algorithm. An important feature of the RLS algorithm is that it utilizes information contained in the input data, extending back to the instant of time when the algorithm is initiated. In this paper, we propose new tap weight updated RLS algorithm in adaptive transversal filter with data-recycling buffer structure. We prove that convergence speed of learning curve of RLS algorithm with data-recycling buffer is faster than it of exiting RLS algorithm to mean square error versus iteration number. Also the resulting rate of convergence is typically an order of magnitude faster than the simple LMS algorithm. We show that the number of desired sample is portion to increase to converge the specified value from the three dimension simulation result of mean square error according to the degree of channel amplitude distortion and data-recycle buffer number. This improvement of convergence character in performance, is achieved at the B times of convergence speed of mean square error increase in data recycle buffer number with new proposed RLS algorithm.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.3
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• pp.241-246
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• 2005

The aim of the study was performed the wave analysis of P-VEP on the development of visual function using Netspeg lens in monocular of refraction error subjects. The P-VEP of three channels were recorded by the Bausch Lomb system. Ten adults (five males, five females, mean=22 years, range=19 to 23) subjects were recorded. The subjects were researched the history including the systemic health, medication, genetics, allergy, ocular disease, and so on. Visual acuity and refraction test were performed for each subject with mono vision by using the Netspeg lens. Also subjects viewed the P-VEP stimulus with mono vision through the corrected visual acuity with Netspeg lens during VEP test. The results of study suggest that the mono vision using Netspeg lens is better than with non-Netspeg lens on the visual acuity and image symptom. On the other hand, the analysis of P-VEP suggest that the amplitude of wave is larger when the eye using Netspeg lens receives the P-VEP stimulus compared with the non Netspeg lens. Also, on the wave style of P-VEP, the eye of Netspeg lens was more stable compared with the naked eye. However, on latency period of P-VEP, the eye of non Netspeg lens was more longer than the eye of Netspeg lens. But, on the other hand, the right and left eye have similar results. In conclusion, this study indicated that the visual acuity and visual function of eye of Netspeg lens used have a better than the eye of non-Netspeg lens in Mono Vision.