• Journal of radiological science and technology
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• v.28 no.1
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• pp.1-7
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• 2005

High-quality single crystals of pure $Li_2B_4O_7$ as well as $Li_2B_4O_7$ doped with Cu, Mn and Mg impurities (1.0mol%, respectively) have been grown from the melt of $Li_2CO_3+2B_2O_3$ by Czochralski method in platinum crucibles. To study the thermoluminescent properties, $Li_2B_4O_7$ series single crystal TLDs were made by cutting in the size of $4{\times}5{\times}1\;mm^3$. The glow curves show two or three peaks which can be easily deconvoluted. It is observed that room temperature($20{\sim}30^{\circ}C$) fadings of the dosimetric peaks of $Li_2B_4O_7$ series single crystal TLDs were about 10 % for 30 days. The relative photon energy response for $Li_2B_4O_7$ series single crystal TLDs were about 85 % when the responses were normalized to that measured with $^{60}Co\;(1.25\;MeV)\;{\gamma}-rays$. The measured data are in a good agreement with theoretical ones. The $Li_2B_4O_7$ series single crystal TLDs fabricated in this work can be used for monitoring personal and environmental radioactivity.

• Journal of radiological science and technology
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• v.28 no.1
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• pp.45-53
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• 2005

This study is aimed at analyzing the relationship between personal factors of radiological technologists and their job stressors. For this aim, a survey was conducted by means of 890 questionnaires from the middle of July to the end of August 2003 to the subjects of radiological technologists who are working for 44 general hospitals in 16 cities and provinces across the country. The results of the survey could be summed up as follows: 1. The biggest stressor that affects a radiological technologist personally under the working situation turned out to be position, job satisfaction and physical symptom(p<0.001), while job satisfaction and physical symptom also played an important role in personal relationship(p<0.001). 2. In terms of job conflicts, colleagues, immediate seniors, job satisfaction and physical symptoms appeared to exercise great impact(p<0.001), As for job autonomy, age, position and job satisfaction were known to be heavily influential(p<0.001). 3. With regard to job load, job satisfaction and behavioral symptom turned out to have great influence while, in job stability, position and job satisfaction seemed to be immensely influential(p<0.001). The present study has a limit in that it covers only radiological technologists who are working at the 3rd reference hospitals but excludes those who are working at the first and second reference hospitals. The findings, however, are surely believed to be able to serve as basic data to improve the medical service quality as they will help reduce the stressors of and enhance mental and physical health for radiological technologists who play important roles as teammates with expertise in the medical field. These outcomes could also be referred to in future studies in this area.

• Journal of radiological science and technology
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• v.29 no.1
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• pp.21-28
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• 2006

I made inquires about mammographic equipments and circumstances of mammography rooms in the 64 medical facilities in areas of Seoul and Kyong Gi Do. Moreover I had experments about exposure dose with patients and radiologic technologists. so there is the data indicated follows. 1. There are inclined to improve in quality and function of mammographic equipments, it has been proven that s/f system exchanged to DR system. 2. It is certain that the number of examinations are becoming increasingly significant. 3. The Space Scattered Dose of mammography rooms are much more larger than portable equipments. 4. I worry about the affection of expose dose about Space Scattered Dose of mammography room. 5. There is need of study how to cope with the situation about increasing exposure dose of radiologic technologists in small space and numeruous number of examinations.

• Journal of radiological science and technology
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• v.29 no.1
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• pp.29-37
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• 2006

The breast cancer has the highest occurrence rate among the female cancers, and as the living style changes, the occurrence is increasing gradually. For the breast cancer test among women, who comprises up to 50% of the total population, the mammography is mainly used as the screening test, and the accuracy control is the most important aspect of the testing. Therefore this research divided the northern part of Kyeongsangbuk-do into 4 regions and investigated the accordance ratio of examination field and light examination field, the total focus using the optical density and compression rate, and the overall maintenance of mammography within the regions. The equipments of 11 hospitals were investigated, and the 7 hospitals passed the standard level of the accordance ratio of examination field. 6 hospitals passed the standard optical density, and 7 hospitals had the passing performance in the compression rate. Fibers, group of specks, and masses within the Mammographic Accreditation Phantom scored 10, being within the standard range. However, only 3 hospitals were equipped with private development processor and illumination. The result reflects the fact that the image quality of breast is not correctly being maintained. Moreover, only 27.27% satisfied all the three categories of compression fitting, accordance ratio of examination field, and phantom image evaluation at the same time. The accuracy control must be maintained more precisely for the accurate diagnosis of breast cancer.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.11
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• pp.2603-2608
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• 2015

Mushroom is a high in protein, low calorie food and has dietary fiber, vitamins, iron and minerals such as zinc. It is called that mushroom is one of the biggest concerns for healthy foods. When we make the artificial cultivation of mushroom, one of the greatest influence element is temperature. In this regard, farmers passively measure temperatures in the greenhouse as inaccurate way such as by the naked eyes. In this paper, we constructed a display system in order to improve the efficiency of manual management of temperature based on the influence of temperature on the mushroom. In related to the methods of mushroom cultivation, the recent technology apply the new technology such as sensors and IT convergence services. And then cultivating mushroom is managed effectively. In this paper, we implement an automatic display system for sensing data. By using this function, farmers could effectively manage environment needed to be grown mushroom, and anticipate the improvement of sales by increasing quality of mushrooms as well.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.1
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• pp.185-191
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• 2015

This paper suggest the safety class communication board in order to design the safety network of the nuclear safety class controller. The reactor protection system use the digitized networks because from analog system to digital system. The communication board shall be provided to pass the required performance and test of the safety class in the digital network used in the nuclear safety class. Communication protocol is composed of physical layer(PHY), data link layer(MAC: Medium Access Control), the application layer in the OSI 7 layer only. The data link layer data package for the cyber security has changed. CRC32 were used for data quality and the using one way communication, not requests and not responses for receiving data, does not affect the nuclear safety system. It has been designed in accordance with requirements, design, verification and procedure for the approving the nuclear safety class. For hardware verification such as electromagnetic test, aging test, inspection, burn-in test, seismic test and environmental test in was performed. FPGA firmware to verify compliance with the life-cycle of IEEE 1074 was performed by the component testing and integration testing.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.7
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• pp.1639-1645
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• 2015

In UHD high-speed video transmission system, when a signal within certain frequency region coincides electrically and structurally, the system becomes unstable because the energy is concentrated, and signal flux is interfered and distorted. For the instability, power integrity analysis should be conducted. To remove the signal distortion for MLB, using a high-frequency design technique for EMI phenomenon, EMI which radiates electromagnetic energy fluxed into power layer was analyzed considering system stabilization. In this paper, we proposed an adaptive MLB design method which minimizes high-frequency noise in MLB structure, enhances signal integrity and power integrity, and suppresses EMI. The characteristic impedance for multi-layer circuit board proposed in this study were High-Speed Video Differential Signaling(HSVDS) line width w = 0.203, line gap d = 0.203, beta layer height h = 0.145, line thickness t = 0.0175, dielectric constant ε_r = 4.3, and characteristic impedance Zdiff = 100.186Ω. When high-speed video differential signal interface board was tested with optimized parameters, the magnitude of Eye diagram output was 672mV, jittering was 6.593ps, transmission frequency was 1.322GHz, signal to noise was 29.62dB showing transmission quality improvement of 10dB compared to previous system.

• Journal of the Korea Institute of Building Construction
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• v.14 no.2
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• pp.127-134
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• 2014

This study had the goal of analyzing the economic feasibility and constructability of a fire resistant curtain wall system using Light-weight Inorganic Composite Foam Board(LI-CFB). LI-CFBs, new materials with excellent fire resistance are being developed for use as the back panel of curtain wall and their fire resistance has already been analyzed through actual tests in earlier studies. In this study, a mock-up test involving the installation of the fire resistant curtain wall system on an actual building was conducted, and the system was compared with a common curtain wall system. This system is applied in the same way as a common curtain wall system. But the cutting LI-CFBs, which are brought from a factory, are used in the system and attached on the frame (mullion and transom). Even though the system requires more working time than the existing system, the LI-CFBs back panels are easy to cut and do not produce dust. Also, the panels are able to be assured the quality by checking damaged parts easily. Besides having a high level of fire resistance, the system's economic feasibility and constructability meets or exceeds those of the existing system.

• Journal of the Korea Institute of Building Construction
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• v.10 no.2
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• pp.97-104
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• 2010

This study evaluated the energy efficiency of a windows system using built-in blinds, with regard to their insulation performance and their blocking of solar radiation. The study took advantage of the "Physibel Voltra" program as a physical simulation of heat transfer. To simulate the "Physibel Voltra" program, I practiced a mock-up test to determine heating quality and translation condition. I analyzed the propensity to annual energy consumption, the annual quantity of heat transfer, and the annual cooling and heating cost through a computer simulation for one general household in an apartment building. In the test, it was found that compared to a general windows system, a windows system with built-in blinds reduced the annual heat transfer by 10% in cooling states and by 11% in heating states when the blind was up. When the blind was down, the windows system with built-in blinds reduced the annual heat transfer by 25% in cooling states and 30% in heating states. When a windows system with built-in blinds is compared with a general windows system, the quantity of cooling and heating loads is reduced by 283.3kw in cooling states and 76.3kw in heating states. This leads to a reduction in the required cooling and heating energy of 359.6kw per house. It is thus judged that the use of a windows system with built-in blinds is advantageous in terms of reducing greenhouse gas emissions, because the annual TOE (tons of oil equivalent) per house is reduced by 0.078TOE, while $tCO_2$ is reduced by $0.16tCO_2$. In addition, compared with a general windows system, the cost of cooling and heating loads in the system reduces the annual cooling cost by 100,000won, and the annual heating cost by 50,000won. Ultimately, this means that cooling and heating loads are cut by 150,000won per year.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.4
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• pp.497-504
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• 2008

This study was conducted for the optimization of ingredients in salad dressing using Bokbunja (Rubus coreanum Miquel) juice. The experiment was designed according to the D-optimal design of mixture design, which included 14 experimental points with 4 replicates for three independent variables (Bokbunja juice $15.70\sim47.10%$, oil $23.50\sim39.20%$, vinegar $3.90\sim19.60%$). The compositional and functional properties of the prepared products were measured, and these values were applied to the mathematical models. A canonical form and trace plot showed the influence of each variable on the quality attribute of final mixture product. By the use of F-test, viscosity, color values (L, a, and b), emulsion stability and sensory characteristics (color) were expressed by a linear model, while the color values (L) and sensory characteristics (smell, taste, and overall acceptance) were by a quadratic model. The optimum formulations by numerical and graphical method were analogous: Bokbunja juice, oil and vinegar of 36.02%, 26.48%, and 12.00% by numerical method, respectively; those of 36.00%, 26.44%, and 12.06% by graphical method, respectively.