• Proceedings of the Korea Contents Association Conference
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• 2016.05a
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• pp.259-260
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• 2016

Our research group, which was organized by the South Korean and Japanese researchers, have carried out research about natural disaster in our regional heritage villages derived from the concept of ICT(information communication technology)-based DPD(disaster prevention design). In this research, we performed simulation analysis on the fire safety diagnosis in Asan-Oeam folk and JeonjuHanok village for developing our research of ICT-based PBD. In order to do this, we used fire simulation program which was developed by BRI(Building Research Institute) of Japan. Based on the results of fire simulation of Asan-Oeam folk and JeonjuHanokvillage, we can demonstrated that the fire which broken out inregional heritage folk village will be easily expanded to adjacent houses, because the house which are built with wood structure.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2299-2301
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• 2001

광 디스크의 용량을 증가시기키 위해선, 레이저 다이오드의 단파장화와 렌즈의 개구수 증가가 수년 동안 시도되어왔다. 불행히도 이러한 노력들은 디스크 틸트(tilt)로 인해 야기되는 코마(coma) 수차로 인한 부작용을 유발하였다. 이런 문제를 해결하기 위해, 램(random access memory, RAM) 디스크의 경우 몇 가지 검출과 보상 방법이 제안되었다. 그러나, 롬(read only memory, ROM) 디스크의 경우 아직까지 뚜렷한 해결책이 제시되지 않고 있다. 본 논문에서는 8분할 광 검출기에 의해 생성되는 차동 위상 검출(differential phase detection, DPD) 신호를 이용한 고밀도 롬 디스크에서 래디얼(radial) 틸트를 검출하는 방법을 제안한다. 3축 렌즈 구동형 액츄에이터(actuator)를 이용하여 개발한 래디얼 틸트 서보로 검출된 래디얼 틸트를 보상한다. 액츄에이터의 회전이 트래킹(tracking) 서보(servo)에 미치는 영향을 소개한다. 끝으로 제안된 방법의 유용성을 고밀도 롬 드라이브에 대한 실험을 통해 검증한다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.1
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• pp.59-67
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• 2003

PMI(Privilege Management Infrastructure) certificates as well as Public-Key certificates must be validated before being used. Validation for a PMI certificate requires PMI certificate path validation, and PKC(Public-Key Certificate) path validations for each entity in the PMI certificate path. This validation work is quite complex and burdened to PMI certificate verifiers. Therefore, this paper suggests a delegated PMI certificate validation that uses specialized validation server, and defines a validation protocol which is used between validation server and client.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.26-32
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• 2010

Purpose: It is to find the way to minimize occupationally exposed dose for workers in vivo tests in each working stage within the range of the working environment which does not ruin the examination and the performance efficiency. Materials and Methods: The process of the nuclear tests in vivo using a radioactive isotope consists of radioisotope distribution, a radioisotope injection ($^{99m}Tc$, $^{18}F$-FDG), and scanning and guiding patients. Using a measuring instrument of RadEye-G10 gamma survey meter (Thermo SCIENTIFIC), the exposure doses in each working stage are measured and evaluated. Before the radioisotope injection the patients are explained about the examination and educated about matters that require attention. It is to reduce the meeting time with the patients. In addition, workers are also educated about the outside exposure and have to put on the protected devices. When the radioisotope is injected to the patients the exposure doses are measured due to whether they are in the protected devices or not. It is also measured due to whether there are the explanation about the examination and the education about matters that require attention or not. The total exposure dose is visualized into the graph in using Microsoft office excel 2007. The difference of this doses are analyzed by wilcoxon signed ranks test in using SPSS (statistical package for the social science) program 12.0. In this case of p<0.01, this study is reliable in the statistics. Results: It was reliable in the statistics that the exposure dose of injecting $^{99m}Tc$-DPD 20 mCi in wearing the protected devices showed 88% smaller than the dose of injecting it without the protected devices. However, it was not reliable in the statistics that the exposure dose of injecting $^{18}F$-FDG 10 mCi with wearing protected devices had 26% decrease than without them. Training before injecting $^{99m}Tc$-DPD 20 mCi to patient made the exposure dose drop to 63% comparing with training after the injection. The dose of training before injecting $^{18}F$-FDG 10 mCi had 52% less then the training after the injection. Both of them were reliable in the statistics. Conclusion: In the examination of using the radioisotope $^{99m}Tc$, wearing the protected devices are more effective to reduce the exposure dose than without wearing them. In the case of using $^{18}F$-FDG, reducing meeting time with patients is more effective to drop the exposure dose. Therefore if we try to protect workers from radioactivity according to each radioisotope characteristic it could be more effective and active radiation shield from radioactivity.

• Journal of Nutrition and Health
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• v.48 no.5
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• pp.381-389
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• 2015

Purpose: The objective of this study was to investigate the effects of a high fructose and fat diet on bone growth and maturation in growing female rats. Methods: Three-week-old female SD rats were randomly assigned to four experimental groups; the control group (CON: fed control diet based on AIN-93G, n = 8); the high-fructose diet group (HFrc: fed control diet with 30% fructose, n = 8); the high-fat diet group (Hfat: fed control diet with 45 kcal% fat, n = 8); and the high-fat diet plus high fructose group (HFrc + HFat: fed diets 45 kcal% fat with 30% fructose, n = 8). Each group was assigned their respective diets for the remaining eight weeks. Bone-related parameters (bone mineral density (BMD) and structural parameters, osteocalcin (OC), deoxypyridinoline (DPD)) and morphologic changes of kidney were analyzed at the end of the experiment. Results: Final body weights and weight gain were higher in the HFat and HFrc + HFat groups and showed higher tendency in the HFrc group compared with those of the CON group (p < 0.05); however, no significant difference in caloric intake was observed among the four experimental groups. The serum OC levels of the HFrc and HFrc + HFat groups were lower than those of the CON and HFat groups (p < 0.05). Urinary levels of DPD did not differ among the experimental groups. BV/TV and Tb.N of trabecular bone were higher in the HFrc + HFat group and showed a higher tendency in the HFrc group than those of the CON and HFat groups (p < 0.05). Tb.Pf of trabecular bone were lower in the HFrc + HFat group than those in the CON and HFat groups (p < 0.05). However, no difference in trabecular BMD was observed among the experimental groups. Cortical bone volume was higher in the HFat and HFrc + HFat groups than in the CON and HFrc groups (p < 0.05). No morphology change in kidney was observed among the experimental groups. Conclusion: Our study suggests that 8 weeks of high-fructose and high fat intake could improve the bone quality (Structural parameters) of trabecular and cortical bone of tibia in growing female rats.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1363-1370
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• 2006

This study was designed to evaluate the effect of Agaricus blazei $\beta-glucan$ and egg shell calcium complex on bone metabolism in ovariectomized (OVX) rats. Forty Sprague-Dewley female rats, 10 weeks of age $(248{\pm}1.7g)$, were divided into 4 groups and fed on the experimental diets for 6 weeks: sham operated control treated with normal diet containing 0.5% calcium (Sham-C), OVX-control treated with normal diet containing 0.5% calcium (OVX-C), $OVX-\beta-glucan$ group treated with $\beta-glucan$ diet containing 0.5% calcium (OVX-G), and $OVX-\beta-glucan$ egg shell calcium complex treated with $OVX-\beta-glucan$ egg shell calcium complex containing 0.5% calcium (OVX-GE). Bone weight of femur was higher in the OVX-GE group than in the other OVX groups. Bone mineral density of femur was significantly different (p<0.05) among the experimental groups and showed the highest level in the OVX-GE group. Calcium absorption rate and retention were higher in the $\beta-glucan$ supplement groups than in the other groups (p<0.05). Alkaline phosphatase activities and osteocalcin levels of serum showed lower in the $\beta-glucan$ supplement groups than in the OVX-C group. Deoxypyridinoline crosslink values of urine, indicator of bone absorption, showed the lowest in the OVX-GE group. The $\beta-glucan$ supplemented groups had a lower bone resorption ratio than in the OVX-C group. We concluded that bioavailability of calcium is higher in $\beta-glucan$ supplement groups compared to those in OVX rats. From the above results, these findings suggest the possibility of using $\beta-glucan$ egg shell calcium complex as a functional food material related to bone metabolism, even though there is no significant difference between the groups of $\beta-glucan$ and $\beta-glucan-egg$ shell calcium complex supplementation.

• Journal of IKEEE
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• v.25 no.1
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• pp.156-167
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• 2021

In this paper, we propose a digital transceiver unit design for in-building of 5G optical repeaters that extends the coverage of 5G mobile communication network services and connects to a stable wireless network in a building. The digital transceiver unit for driving the proposed 5G optical repeater is composed of 4 blocks: a signal processing unit, an RF transceiver unit, an optical input/output unit, and a clock generation unit. The signal processing unit plays an important role, such as a combination of a basic operation of the CPRI interface, a 4-channel antenna signal, and response to external control commands. It also transmits and receives high-quality IQ data through the JESD204B interface. CFR and DPD blocks operate to protect the power amplifier. The RF transmitter/receiver converts the RF signal received from the antenna to AD, is transmitted to the signal processing unit through the JESD204B interface, and DA converts the digital signal transmitted from the signal processing unit to the JESD204B interface and transmits the RF signal to the antenna. The optical input/output unit converts an electric signal into an optical signal and transmits it, and converts the optical signal into an electric signal and receives it. The clock generator suppresses jitter of the synchronous clock supplied from the CPRI interface of the optical input/output unit, and supplies a stable synchronous clock to the signal processing unit and the RF transceiver. Before CPRI connection, a local clock is supplied to operate in a CPRI connection ready state. XCZU9CG-2FFVC900I of Xilinx's MPSoC series was used to evaluate the accuracy of the digital transceiver unit for driving the 5G optical repeater proposed in this paper, and Vivado 2018.3 was used as the design tool. The 5G optical repeater digital transceiver unit proposed in this paper converts the 5G RF signal input to the ADC into digital and transmits it to the JIG through CPRI and outputs the downlink data signal received from the JIG through the CPRI to the DAC. And evaluated the performance. The experimental results showed that flatness, Return Loss, Channel Power, ACLR, EVM, Frequency Error, etc. exceeded the target set value.

• International Journal of Industrial Entomology and Biomaterials
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• v.30 no.1
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• pp.17-25
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• 2015

This study aimed to investigate the effects of silk fibroin on bone metabolism in ovariectomized rats. A total of 30 Sprague-Dawley rats were randomized into sham-operated (SHAM), ovariectomized control (OVX), alendronate (OVX+ALEN, 10 mg/kg body weight/d), low silk fibroin (OVX+SF100, 100 mg/kg body weight/d), and high silk fibroin (OVX+SF300, 300 mg/kg body weight/d) groups. All the rats were fed by gavage for 12 wk. At the end of 12 wk, blood and urine were collected for analysis of bone turnover markers, and bone mineral density (BMD) was measured by micro-computed tomography. The results show that the OVX group (p < 0.05) displayed the highest mean body weight gain. Among the five groups, serum levels of bone alkaline phosphatase (ALP) and urine levels of deoxypyridinoline (DPD) were highest in the OVX group (p < 0.05). Bone ALP levels in the ALEN group were significantly lower than that of the silk-treated groups. On the other hand, DPD levels were not significantly different between the ALEN and silk-fibroin-treated groups (p < 0.05). The trabecular BMD was significantly higher in the ALEN and silk-treated groups compared to the OVX group (p < 0.05). In conclusion, this study showed that silk fibroin has similar effects as alendronate, which is used in osteoporosis medication. Therefore silk fibroin might be a new candidate for the prevention and treatment of osteoporosis in patients.

• Journal of Nutrition and Health
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• v.48 no.2
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• pp.149-156
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• 2015

Purpose: This study examined the effects of combined intervention of isoflavones and exercise on bone mineral density, bone mineral content, and biochemical bone markers. Methods: Forty rats were divided into four groups; Control, Isoflavones (IF), Isoflavones + Running (IFR), and Isoflavones + Swimming (IFS). All of the rats in this study were fed an experimental diet and deionized water ad libitum for nine weeks. Bone mineral density (BMD) and bone mineral content (BMC) were estimated using PIXImus (GE Lunar Co, Wisconsin.) in spine and femur nine weeks after feeding or training. Results: The combined intervention did not affect weight gain, mean food intake, or food efficiency ratio. The serum concentrations of ALP and osteocalcin were not significantly different by combined intervention. The urinary DPD crosslinks values were not significantly different by combined intervention. There were no significant differences in serum PTH, calcitonin, and estradiol among all groups. Spine BMD, spine BMC and femur BMC were not significantly different by combined intervention. However, femur BMD was significantly higher in the IFR group than in the control group. Compared with the control group, spine BMD, spine BMC, and femur BMD per weight were markedly increased in the isoflavones supplementation and combined intervention group. In addition, femur BMC per weight was significantly higher in the IFS group than in the control group. Compared with the isoflavones supplemented group, BMD and BMC were not significantly different by combined intervention. Conclusion: It can be concluded that isoflavones supplementation or combined intervention of isoflavone and exercise had a beneficial effect on spine and femur peak bone mass in growing female rats.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.8
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• pp.854-861
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• 2008

We have described a high power hybrid envelope elimination and restoration(H-EER) transmitter for IEEE 802.16e Mobile World Interoperability for Microwave Access(WiMAX) using an efficiency optimized power amplifier(PA). The PA has been designed to have maximum PAE at the important power generation $V_{ds}$, region using Nitronex 100-W PEP GaN HEMT. For the high power application, H-EER transmitter should be considered the regenerative oscillation problem due to the PA's bias fluctuation effect and bias modulator stability issue. Therefore, the bias modulator for H-EER transmitter has been designed to suppress the regenerative oscillation. For the interlock experiment, the bias modulator has been built with the efficiency of 72% and peak output voltage of 30 V for the envelope signal with a PAPR of 8.5 dB. The H-EER transmitter for WiMAX application has been achieved a high PAE characteristic, 38.8 % at an output power of 41.25 dBm. By using digital predistortion(DPD) technique, the Relative Constellation Error (RCE) has been satisfied the specification of -34.5 dB. This is the first work at 2.655 GHz high power H-EER transmitter for WiMAX application.