• Journal of radiological science and technology
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• v.27 no.4
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• pp.11-16
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• 2004

Classification of esophageal motility disorders not yet finalized and is still ongoing as the new disorders are reported, and the existing classification is changed or removed. In terms of radiology, the primary peristalsis does not exist, and the lower end of the esophagus show the smooth, tapered, beak-like appearance. The esophageal motility disorder, which mostly occurs in the smooth muscle area, show the symptoms of reduction or loss (hypomotility) or abnormal increase (hypermotility) of peristalsis of the esophagus. It is important to understand the anatomy and physiology of the esophagus for the appropriate radiological method and diagnosis. Furthermore, the symptom of the patient and the manometry finding must be closely referred for the radiological diagnosis. The lower esophageal sphincter can be normally functioning and open completely as the food moves lower. Sperandio M et al. argues that the name diffuse esophageal spasm must be changed to distal esophageal spasm (DES) as most of the spasm occurs in the distal esophagus, composed of the smooth muscle. According to Ott et al., usefulness of barium method for diagnosing the esophageal motility disorder is Achalasia 95%, DES 71% and NEMD 46%, with the overall sensitivity of 56%. However, excluding the nutcracker esophagus or nonspecific disorder which cannot be diagnosed with the radiological methods, the sensitivity increases to 89%. Using videofluoroscopy and 5 time swallows, the average sensitivity was over 90%. In conclusion, the barium method is a simple primary testing method for esophageal motility test. Using not only the image but also the videofluoroscopy with good knowledge of the anatomy and physiology, it is believed that the method will yield the accurate diagnosis.

• Journal of the Korea Society for Simulation
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• v.18 no.3
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• pp.73-82
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• 2009

Due to the many advantages including low price, low power consumption, and miniaturization, the CMOS camera has been utilized in many applications, including mobile phones, the automotive industry, medical sciences and sensoring, robotic controls, and research in the security field. In particular, the 360 degree omni-directional camera when utilized in multi-camera applications has displayed issues of software nature, interface communication management, delays, and a complicated image display control. Other issues include energy management problems, and miniaturization of a multi-camera in the hardware field. Traditional CMOS camera systems are comprised of an embedded system that consists of a high-performance MCU enabling a camera to send and receive images and a multi-layer system similar to an individual control system that consists of the camera's high performance Micro Controller Unit. We proposed the SL-AVS (Small Size/Low power Around-View System) to be able to control a camera while collecting image data using a high speed synchronization technique on the foundation of a single layer low performance MCU. It is an initial model of the omni-directional camera that takes images from a 360 view drawing from several CMOS camera utilizing a 110 degree view. We then connected a single MCU with four low-power CMOS cameras and implemented controls that include synchronization, controlling, and transmit/receive functions of individual camera compared with the traditional system. The synchronization of the respective cameras were controlled and then memorized by handling each interrupt through the MCU. We were able to improve the efficiency of data transmission that minimizes re-synchronization amongst a target, the CMOS camera, and the MCU. Further, depending on the choice of users, respective or groups of images divided into 4 domains were then provided with a target. We finally analyzed and compared the performance of the developed camera system including the synchronization and time of data transfer and image data loss, etc.

• Korean Journal of Weed Science
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• v.17 no.3
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• pp.295-302
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• 1997

The study conducted to know the effect of growth and yield by different weed control duration using by 'chalok 1 ho', waxy maize, at Suweon in 1995. The emergence of weed and growth and yield of waxy maize on weedy check and 10, 20, 30, 40, 50, 60, 70, 80, and 90 days weed control and whole season weed control during cultivation summrized as follows; 1. Chenopodium album, Echinochoa crus-galli, Persicaria hydropiper and Panicum bisulcatum emerged as major weeds and dominant weed was Chenopodium album. 2. The number of emerged weeds grouped by mophologically ordered broad leaf weeds, grass weeds and sedge weeds. 3. 30 days weed control duration from the sowing effect to silking stage and 40 days weed control duration from the sowing decreased stem length, ear length, ear weight, number of plant, and number of ear. 4. The yield of weedy check, and 10 days weed control from the sowing showed no yield and 20, 30 and 40 days weed control from the sowing decreased to 76, 64 and 33 %, individually. 5. The yield loss of waxy maize on weeds can be prevent by 40 days weed control duration from the sowing.

• 한국벤처창업학회:학술대회논문집
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• 2008.11a
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• pp.257-282
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• 2008

RFID (Radio Frequency Identification) is regarded as a core technology of ubiquitous computing. Although it has some technical limitations such as technological standardization of RFID tags as well as economical limitations, many companies around the world have already accepted RFID to improve their management efficiency. In this regard, this study is to meet with results that the adoption of RFID technology willbring opportunities that companies' operational process are improved and customer satisfaction is highly strengthened. This research focuses on providing more understanding for building RFID marketing strategy to suppliers who want to sell their RFID products to customers through analyzing purchasing process. The findings are as follows; First, the study shows that buying center members usually take product reliability and precision of technical specification in the case of new-task buying situation while they put their first purchasing priority on prices in the straight rebuy. Second, the finding presents that in new-task buying situation and the straight rebuy purchasing personnel get information about new products through product performance test, organizational engineers, opinions from other companies' purchasing personnel, and checking out samples. Third, this research demonstrates when it comes to purchasing risk in their first purchasing, the persons who are in charge of material purchasing are inclined to be aware of the risk most in technical problems, followed by financial problems and time delay problems in order. And in addition to those risks are mentioned above, once-again-purchasers take the risk like an opportunity loss for better products into consideration. Fourth, the study shows that the role of concerning departments makes no difference in each purchasing stage. Accordingly marketers need to beef up the differentiated strategy to persuade their customers. Fifth, the findings of this study demonstrate that purchasing decision making is much influenced by the final users. So suppliers are supposed to perform the most active marketing strategy at the first stage of purchasing through various resources. Finally, the study presents that the suppliers who will have had close relationships with their customers need to give consistent information to them so that their customers can have lower motive in purchasing products from competitors.

• Korean Security Journal
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• no.21
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• pp.155-175
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• 2009

RFID that provide automatic identification by reading a tag attached to material through radio frequency without direct touch has some specification, such as rapid identification, long distance identification and penetration, so it is being used for distribution, transportation and safety by using the frequency of 125KHz, 134KHz, 13.56MHz, 433.92MHz, 900MHz, and 2.45GHz. Also it is one of main part of Ubiquitous that means connecting to net-work any time and any place they want. RFID is expected to be new growth industry worldwide, so Korean government think it as prospective field and promote research project and exhibition business program to linked with industry effectively. RFID could be used for access control of person and vehicle according to section and for personal certify with password. RFID can provide more confident security than magnetic card, so it could be used to prevent forgery of register card, passport and the others. Active RFID could be used for protecting operation service using it's long distance date transmission by application with positioning system. And RFID's identification and tracking function can provide effective visitor management through visitor's register, personal identification, position check and can control visitor's movement in the secure area without their approval. Also RFID can make possible of the efficient management and prevention of loss of carrying equipments and others. RFID could be applied to copying machine to manager and control it's user, copying quantity and It could provide some function such as observation of copy content, access control of user. RFID tag adhered to small storage device prevent carrying out of item using the position tracking function and control carrying-in and carrying-out of material efficiently. magnetic card and smart card have been doing good job in identification and control of person, but RFID can do above functions. RFID is very useful device but we should consider the prevention of privacy during its application.

• Applied Biological Chemistry
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• v.29 no.3
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• pp.288-293
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• 1986

The washed fresh ginsengs packed with air, vaccum and nitrogen gas were irradiated at the levels of 1,2 and 3kGy gamma radiation and then stored at $4{\sim}5^{\circ}C$ for 90days to investigate the effects of gamma radiation on microbial inactivation, eelworm disinfestation and physicochemical changes. After a 90 day storage, $2{\sim}3kGy$ irradiated groups showed 20% of weight loss and 10% of rot while non-irradiated group 100% and 20% or more, respectively. Also the irradiated groups showed somewhat lower values of specific gravity, color density and hardness immediately after irradiation, thereafter higher value of them with storage time than those of non-irradiated group. The irradiation increased the yields of ginseng extract and crude saponins but no effects on the proximate composition and TLC and HPLC patterns of saponin. The food-borne microorganisms decreased in viable cell counts by $2{\sim}3$ log cycles with $2{\sim}3kGy$ radiation and the eelworms were completely disinfested with 1 kGy radiation.

• The Journal of Society for e-Business Studies
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• v.26 no.3
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• pp.55-66
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• 2021

The mobile application (APP) market is growing at an unprecedented speed. Amid such growth, the global platform providers are mandating exclusive in-app payments and charging 30% for platform commission fees. A serious tension has arisen between mobile global platform providers and local content providers. The present study attempts to analyze the domestic mobile game market and in-app payment commission fees. This study estimates the size of the domestic mobile game market and platform commission fees by directly using publicly available financial statements and footnote information of some representative listed mobile game firms. Also, the study analyzes the cost structures of the same sample firms and attempts to draw some implications on sustainable growths of the mobile game ecosystem. We estimated that, in 2019, the domestic mobile game market is around 4.9 trillion Won and the ensuing in-app payment commission fees market was 1.5 trillion Won. High market share firms display a proportional increase in in-app payment commission fees in relation to sales growth. This, in turn, makes the in-app payment commission fees a primary cost item far exceeding employee salaries and R&D expenses. During the same period, low market share firms generated a mere profit or experienced net loss. Analysis of the cost structure reveals that these firms are even more liable to higher in-app payment commission fee cost structure than high market share. Most constituents of the mobile game ecosystem are small business entrepreneurs. By employing a micro-level analysis, the study estimates that, in 2019, a representative median firm generates 530 million Won in sales. At the same time, it spends 190 million Won in employee salaries, 50 Won million in R&D and 190 million Won in in-app payment commission fees, respectively. In the absence of other cost items, these three cost items alone account for 73.8% of sales revenue. The results imply that a sustainable growth of the local mobile game market heavily depends upon the cost structure of such representative median firm, the in-app payment commission fees being the primary cost item of such firm.

• Food Science and Preservation
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• v.17 no.1
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• pp.1-8
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• 2010

We investigated the effect of freezing on changes in the chemical components of semi-dried red pepper (SDRP). We used storage temperatures of $0^{\circ}C,\;-10^{\circ}C,\;-20^{\circ}C,\;and\;-70^{\circ}C$. After 30 days of storage, capsaicin content had decreased by 40% at $0^{\circ}C$ and by 21% at $-20^{\circ}C$. Initial vitamin C content was 1,358.02 mg%. Compared with control, the $0^{\circ}C$ storage group showed a significant decrease in vitamin C content but no such decrease was noted in the $-20^{\circ}C$ and $-70^{\circ}C$ storage groups after 30 days. ASTA values were not influenced by storage temperature or period, in agreement with previous results. We concluded that storage was effective at temperatures of less than $-20^{\circ}C$. Next, both dried red pepper (DRP) and SDRP were stored at $-20^{\circ}C$ for 12 months. DRP had the lower level of capsaicinoids (55.01 mg%) owing to the long drying time. After 12 months, SDRP capsaicinoid had decreased by 30-33%, compared with a decrease of 54% in DRP. Initial vitamin C contents were 721.48 and 955.25 mg% in DRP and SDRP, respectively, and, after 12 months, vitamin C loss in the SDRP group (37%) was less than that in fresh red pepper (FRP) samples (45%). Initial $\beta$-carotene content was greatest in the FRP group (259.82 mg%), and that of DRP decreased by 20% after 12 months. The color a/b value of SDRP (1.40) was greater than that of DRP (1.00).

• Korean Chemical Engineering Research
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• v.54 no.6
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• pp.863-870
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• 2016

We investigated the physical/chemical phenomena that a slow loss of $CO_2$ inventory into sodium after the sodium-$CO_2$ boundary failure in printed circuit heat exchangers (PCHEs), which is considered for the supercritical $CO_2$ Brayton cycle power conversion system of a sodium-cooled fast reactor (SFR). The first phenomenon is plugging inside narrow sodium channels by micro cracks and the other one is damage propagation referred to as wastage combined with the corrosion/erosion effect. Experimental results of plugging shows that sodium flow immediately stopped as $CO_2$ was injected through the nozzle at $300{\sim}400^{\circ}C$ in 3 mmID sodium channels, whereas sodium flow stopped about 60 min after $CO_2$ injection in 5 mmID sodium channels. These results imply that if pressure boundary of sodium-$CO_2$ fails a narrow sodium channel would be plugged by reaction products in a short time whereas a relatively wider sodium channel would be plugged with higher concentration of reaction products. Wastage by the erosion effect of $CO_2$ (200~250 bar) hardly occurred regardless of the kinds of materials (stainless steel 316, Inconel 600, and 9Cr-1Mo steel), temperature ($400{\sim}500^{\circ}C$), or the diameter of the $CO_2$ nozzle (0.2~0.8 mm). Velocities at the $CO_2$ nozzle were specified as Mach 0.4~0.7. Our experimental results are expected to be used for determining the design parameters of PCHEs for their safeties.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.1
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• pp.29-37
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• 2011

Purpose: In cases when implant supported overdenture is made by using standard size implant, additional procedure such as bone surgery and bone grafting can be required. And it gives burden to doctor and patient in terms of cost. Therefore, it is necessary to find the implant therapy for the edentulous patients in making denture with accordable cost and simple procedure. Materials and methods: Edentulous patients with upper and lower dentures participated in this study. Before the operation, survey about patient's satisfaction to the existing dentures was carried out. Surgical procedures included four small diameter implants installation anterior area and immediate loading. One and three month after the procedure, the same survey about patient's satisfaction was carried out, and radiography was taken. Results: We are doing research to the nine patients. Survival rate is 97.2 percent. The comparison of patient's satisfaction before and after surgery is performed based on oral health impact profile 49. We analyze mainly with masticatory discomfort, retention, aesthetics, social problem, psychological discomfort problems. As a result, satisfaction level is increased at all factors. Retention is the most increased satisfactory factor followed by mastication difficulty, pronunciation, psychological discomfort, social discomfort, aesthetics in order. Marginal bone loss is 0.21 mm at 12 weeks after implant placement. Conclusion: This research reveals that the denture supported by mini dental implant increases patient's satisfaction. This study will be continued with more patients for a long time and we are scheduled for taking additional radiography to check whether peri-implant bone resorption occurs or not.