• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.4
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• pp.62-70
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• 2015

Recently the demand for projected capacitance touch screens is sharply growing especially for large screens for medical devices, PC monitors and TVs. Large touch screens in general need a controller of higher complexity. They usually have a larger number of driving and sensing lines, and hence it takes longer to scan one frame for touch detection leading to a low frame scan rate. In this paper, a novel touch screen control technique is presented, which scans each frame in two steps of simultaneous multi-channel driving. The first step is to drive all driving lines simultaneously and determine which sensing lines have any touch. The second step is to sequentially rescan only the touched sensing lines, and determine exact positions of the touches. This technique can substantially increase the frame scan rate. This technique has been implemented using an FPGA and an AFE board, and tested using a commercial 23-inch touch screen panel. Experimental results show that the proposed technique improves the frame scan rate by 8.4 times for the 23-inch touch screen panel over conventional methods.

• Journal of Food Hygiene and Safety
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• v.34 no.1
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• pp.73-86
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• 2019

Seafaring is an important occupation that requires stringent hand hygiene practices as a basic method for preventing food-borne illness and infectious diseases when the diseases occur on board. The purpose of this study is to provide fundamental data for the prevention of food-borne illness and infectious disease on the ship by investigating the level of hand hygiene practices and influencing factors. A total of 222 seafarers were surveyed at a seafarers' educational institution between July and August 2017. Their hand hygiene practice were examined by a modified method using the guidelines which are recommended by the World Health Organization, the Centers for Disease Control and Prevention, and Hand Hygiene Australia. The mean of hand hygiene practice was 47.97 out of 75 points. By category, the most frequent hand hygiene practice was measured as 4.04 on a 5-point scale as 'after working'. Factors affecting hand hygiene practices were ship tonnage relating to in job characteristics, exercise in health-related characteristics, and soap in relation to the characteristics of the hand hygiene environment on board. To improve hand hygiene among seafarers, it is necessary to raise awareness of hand hygiene among seafarers who work on small ships in particular, and to improve the systems of hand hygiene on ships with continuous education, hygiene practice evaluation and feedback.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.4
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• pp.456-465
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• 2019

PHEV(Plug in Hybrid Electric Vehicle) and BEV(Battery Electric Vehicle) equip high voltage batteries to drive motor and vehicle electric system. Those vehicle require OBC(On-Board Charger) for charging batteries and LDC(Low DC/DC Converter) for converting from high voltage to low voltage. Since the charger and the converter actually separate each other in electrical vehicles, there is a margin to reduce the vehicle weight and area of installation by integration two systems. This paper studies a 1.5kW LDC converter that can be integrated into an OBC using an isolated current-fed converter by simplifying the design of LDC transformers. The proposed LDC can control the final output voltage of the LDC by using a fixed arbitrary output voltage of the bidirectional buck-boost converter, so that Compared to the existing OBC-LDC integrated system, it has the advantage of simplifying the transformer design considering the battery voltage range, converter duty ratio and OBC output turn ratio. Prototype of the proposed LDC was made to confirm normal operation at 200V ~ 400V input voltage and maximum efficiency of 91.885% was achieved at rated load condition. In addition, the OBC-LDC integrated system achieved a volume of about 6.51L and reduced the space by 15.6% compared to the existing independent system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.2
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• pp.104-110
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• 2019

In this paper, a complementary metal oxide semiconductor(CMOS) power amplifier(PA) integrated circuit operating in the 900 MHz band for long-term evolution(LTE) communication systems is presented. The output matching network based on a transformer was implemented on a printed circuit board for low loss. Simultaneously, to achieve high efficiency of the PA, the second harmonic impedances are controlled. The CMOS PA was fabricated using a $0.18{\mu}m$ CMOS process and measured using an LTE uplink signal with a bandwidth of 10 MHz and peak to average power ratio of 7.2 dB for verification. The implemented CMOS PA module exhibits a power gain of 24.4 dB, power-added efficiency of 34.2%, and an adjacent channel leakage ratio of -30.1 dBc at an average output power level of 24.3 dBm.

• Journal of Advanced Navigation Technology
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• v.24 no.6
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• pp.566-572
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• 2020

In a wireless power transmitter, the characteristics and effects of wireless power transmission between two induction coils are investigated, and a power converter circuit and a battery charger/discharger circuit using wireless power transmission technology are proposed. The advantage of wireless power transmitters and wireless chargers is that, instead of the existing plug-in-mounted wired charger (OBC; on-board charger), the user can wirelessly charge the battery without connecting the power source when charging power to the battery. There is. In addition, the advantage of wireless charging can bring about an energy efficiency improvement effect by using the secondary side rectifier circuit and the receiving coil, but the large-capacity long-distance wireless charging method has a limitation on the transmission distance, so many studies are currently being conducted. The purpose of the study is to study the transmitter circuit and receiver circuit of a wireless power transmission device using a primary coil, a secondary coil, and a half bridge series resonance converter, which can transmit power of a non-contact type power transmitter. As a result, a new topology was applied to improve the power transmission distance of the wireless charging system, and through an experiment according to each distance, the maximum efficiency (95.8%) was confirmed at an output of 3 kW at an 8 cm transmission distance.

• Journal of the Korean Wood Science and Technology
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• v.32 no.2
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• pp.9-18
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• 2004

This study was carried out to find the efficient methods for preventing resin exudation from spruce board during high temperature environment service.In the dry-air oven test, in-use temperature related to resin exudation of 110℃ could be obtained by the appropriate kiln drying without any special treatment, and the in-use temperature of the radio-frequency/vacuum (RF/V)-dried boards was about 20℃ higher than that of the conventional kiln-dried boards.In the autoclave test, resin exudation was not found from any board dried in the conventional kiln and in the RF/V kiln after the low pressure steam explosion (SE) treating, while for the control resin exudations were more severe in the autoclave test above 130℃ than in the dry-air oven test. It, therefore, would be suggested that resin exudation during high temperature service condition can be prevented more effectively by super-heated steaming green boards than by high-temperature drying boards with low moisture.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.1013-1022
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• 2022

Recently, with the worldwide development of the fourth industry, the development of technologies for smart and eco-friendly ships is accelerating. With the emergence of autonomous vessels with complete unmanned or minimum personnel on board and eco-friendly fuel (methane, ammonia, electricity, etc.), the role of existing seafarers on board is expected to change significantly. To improve the competitiveness of seafarers in the future, predicting future seafarer occupation groups, improving the educational curriculum, and creating an educational system are necessary. In this study, eight occupational groups that seafarers may have in the future were derived through a review of earlier studies and brainstorming of maritime university students, incumbent seafarers and expert groups. A survey was conducted on the eight occupational groups using the Likert scale, and based on the results, a leading occupational group related to future seafarer was derived. The most likely occupational groups with high scores were remote control centre operators and cargo remote manager. In addition, essential educational elements to be educated first for these occupational groups were derived and presented.

• Journal of Nutrition and Health
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• v.9 no.4
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• pp.19-27
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• 1976

Perilla (frutescens) seed oil, which is widely used as a source of vegetable oil in Korea, contains a strikingly large amount (58.4% of total fatty acids) of polyunsaturated linolenic acid (18 : 3) which is one of the essential fatty acids. Our hypothesis was that vitamin E contained in this oil would not be enough to prevent peroxidation of this polyunsaturated oil. A comparative study was carried out using rats and chicks devided into seven groups with various diet combinations emphasizing fat sources for the period of four weeks. The level of fat in each diet was 15% and animals were fed ad libitum. Various diet combinations were as follows; perilla seed oil and sesame seed oil with and without vitamin E supplementation, tallow as a saturated fat source and perilla seed hull group (10% at the expense of carbohydrate). The fat constituents of control group were consisted of 50% vegetable oil and 50% animal fat. A few important findings are as follows: 1. Rats fed perilla seed oil lost their hair focally around the neck and suffered from a bad skin lesion at the same place. In chicks, yellow pigmentation both of feather and of skin was clearly observed only in groups fed perilla seed oil with or without vitamin E supplementation. The basis of biochemical mechanisms of this phenomena remains as an important research interest. 2. The mean value for hematocrit was significantly lower for the chicks fed perilla seed oil than for those fed control diet. This result seems to be attributable to the effect on the red cell membrane known as peroxidation-hemolysis of vitamin E deficiency. 3. The serum cholesterol level was higher for the rats fed perilla seed oil than for those fed control diet, whereas in chicks the group fed perilla seed oil showed lower value than the control group indicating that different animal species could vary in their responses to the same diet. 4. In pathological examinations, the sign of hepatic fibrosis was seen in the perilla seed hull group and it was noticeable that the level of hepatic RNA was significantly increased in the rat recovering from vitamin E deficiency. It is hoped that more detailed studies on perilla seed oil and hulls will soon be carried out in many aspects especially i) at various levels of fat in the diet, ii) in relation to dietary selenium level and iii) to find an optimum level of dietary essential fatty acids in terms of P/S ratio using various animal species. In the mean time, the public should be informed to preserve this particular oil with care to minimize fatty acid oxidation and should be discouraged from overconsuming this oil. This study was supported by UB (United Board) Research Grant (Graduate School, Yonsei University, Seoul, Korea)

• Journal of Food Hygiene and Safety
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• v.3 no.3
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• pp.117-129
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• 1988

Packaged meal manufacturing establishments in Seoul city and Kyungkido province were assessed in terms of the sanitary conditions and practices, time and temperature, and microbiological quality. Sanitary check-lists were developed to evaluate the sanitary condition of sampled packaged meal manufacturing establishments. Microbiological tests on.food containers, equipments, and foods in various phases of product flow were done. The results of the study are summarized as follows; 1) Sanitary condition of kitchen.and sanitary practices of employees in.large and medium establishments were evaluated as the some improvement required in order to meet all standards. But sanitary practices of employees in small establishments were evaluated as the unsatisfactory state with negligence or ignorance of safe practice. 2) The microbiological quality of basic ingredients and food materials after pre-preparation were poor. 3) Time and temperature data indicated that phases of holding ingredients at room temperature after cooking, assembly and packaging before delivery were critical. 4) Microbiological test results for food containers, equipments indicated that sanitary conditions of stainless steel ware, knife, wiping clothes and cutting board should be improved promptly. 5) Critical control points identified were ingredients, pre-preparation, Holding, and assembly and packaging. 6) Guidelines were suggested for effective quality control of packaged meals production.

• Journal of Internet Computing and Services
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• v.8 no.1
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• pp.33-45
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• 2007

Using switches and sensors informing the current on or off state, this paper suggests a sleeping control and remote monitoring system that not only can recognize the sleeping situations but also can control for keeping an appropriate sleeping situation remotely, And we show an example that this system is applied to the healthcare sleeping mat, Our system comprises the following 3 parts: a part for detecting the sleeping situations, a part for extracting sensing data and sending/receiving the relating situated data, and a part controlling and monitoring the all of sleeping situations. In details, in order to develop our system, we used the touch and pressure-sensitive sensors with On/Off functions for a purpose of the first part, The second part consists of the self-developed embedded board with the socket based communication as well as extracting real-time sensing data. And the third part is implemented by service modules for providing controlling and monitoring functions previously described. Finally, these service modules are implemented by the TMO scheme, one of real-time object-oriented programming models and the communications among them is supported using the TMOSM of distributed real-time middleware.