• Journal of Radiation Protection and Research
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• v.37 no.1
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• pp.10-15
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• 2012

Design and performance test results of a newly developed optically stimulated luminescence (OSL) measurement system are presented in this paper. Generally, different types of optical filters are used in OSL reader system to minimize the interference of the stimulation light in the OSL signal. For optically stimulation of $Al_2O_3:C$, we have arrived at an optimal combination of the filters, i.e., GG420 filter for filtering the stimulating light source, and a combined UG11 and BG39 filter at the detecting window (PMT). By using a high luminance blue LED (Luxeon V), sufficient luminous intensity could be obtained for optically stimulation. By using various control boards, the OSL reader device was successfully interfaced with a personal computer. A software was developed to deliver required commands to operate the OSL reader by using the LabView program (National Instruments, Inc.). In order to evaluate the reliability and the reproducibility of newly designed-OSL reader. Performance testing of the OSL reader was carried out for OSL efficiency, OSL decay curve and signal to noise ratio of the standard $Al_2O_3:C$ OSL material. It was found to be comparable with that of commercial Riso reader system.

• BMB Reports
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• v.42 no.1
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• pp.59-64
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• 2009

Hepatitis B virus (HBV) infection is highly prevalent worldwide. The major challenge for current antiviral treatment is the elevated drug resistance that occurs via rapid viral mutagenesis. In this study, we developed AAV vectors to simultaneously deliver two or three shRNAs targeting different HBV-related genes. These vectors showed markedly better antiviral effects than ones that delivered a single shRNA in vitro. A dual shRNA expression vector (AAV-157i/1694i), which simultaneously expressed two shRNAs targeted the S and X genes of HBV, reduced HBsAg, HBeAg and HBV DNA levels by $87{\pm}4$, $80.3{\pm}2.6$ and $86.2{\pm}7%$ respectively, eight days post-transduction. In a mouse model of prophylactic treatment, HBsAg and HBeAg were reduced to undetectable levels and the serum HBV DNA level was reduced by at least 100 fold. These results indicate that AAV-157i/1694i generates potent anti-HBV effects and that the strategy of constructing multi-shRNA expression vectors may lead to enhanced anti-HBV efficacy and overcome the evading mechanism of the virus and thus the development of drug resistance.

• The Journal of the Acoustical Society of Korea
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• v.24 no.6
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• pp.317-324
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• 2005

Detection and localization of a quiet target in shallow water environments is a challenging problem because of the complicated acoustic Propagation and the Prevalence of loud surface ship interference. Matched Field Processing (MFP) can help address the concern by using a Propagation model to determine the steering vectors, thus Providing optimal away gain and localization accuracy. However, Performance of MFP have yet realized in practice, for several reasons. The most important limitation is that precise information on the underwater environments is generally not available. To examine the Performance of MFP in the East Sea of Korea, we have accomplished a series of matched acoustic Properties and localization experiment (MAPLE). We analyzed the array data measured from MAPLE which is accomplished using a vertical line array and a towed acoustic source off the east cost of Korea in Oct. 2003. We localized the acoustic source using MFP. It is well known that the temperature structure in the experimental site is affected by the short period fluctuation such as internal wave. In this paper, it is found that the sidelobe level on the MFP ambiguity surface is increased being affected by the short period fluctuation.

• The Journal of the Acoustical Society of Korea
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• v.37 no.1
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• pp.73-81
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• 2018

The quality of side scan sonar images is determined by the frequency of a sonar. A side scan sonar with a low frequency creates low-quality images. One of the factors that lead to low quality is a high-level noise. The noise is occurred by the underwater environment such as equipment noise, signal interference and so on. In addition, in order to compensate for the transmission loss of sonar signals, the received signal is recovered by TVG (Time-Varied Gain), and consequently the side scan sonar images contain non-homogeneous noise which is opposite to optic images whose noise is assumed as homogeneous noise. In this paper, the SSCS (Structural Sparsity based Compressive Sensing) is proposed for removing non-homogeneous noise. The algorithm incorporates both local and non-local models in a structural feature domain so that it guarantees the sparsity and enhances the property of non-local self-similarity. Moreover, the non-local model is corrected in consideration of non-homogeneity of noises. Various experimental results show that the proposed algorithm is superior to existing method.

• Journal of the Institute of Convergence Signal Processing
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• v.19 no.3
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• pp.139-146
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• 2018

Underwater acoustic communication can be applied to various area such as scientific, commercial and military survey using Autonomous Underwater Vehicles and Unmanned Underwater Vehicles. Underwater communication is studying very actively by advanced country like United States. But differ from wireless communication in the air, underwater acoustic communication has some difficult problems, ISI(Inter Symbol Interference) due to multipath and limit of transmission bandwidth due to slow propagation of sound wave. In this paper, SC-FDE and OFDM transmission system for the cancellation of ISI in conjunction with underwater acoustic channel modeling are applied to the underwater simulation of communication. The performance of these methods in the simulation guide to possibility of adopting in underwater acoustic communication algorithm. For this purpose, we compare SER performance of SC-FDE with that of OFDM for modelled underwater channel. Underwater channel is generated by Bellhop model. Simulation results show above 5dB SNR gain at 10-3 SER. And it demonstrate SC-FDE is efficient method for underwater acoustic communication.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06c
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• pp.265-267
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• 2006

사용목적(Purpose)은 최근 개인 프라이버시 보호와 관련하여 데이타 수집과 수집 후 보안관리에 있어서 중요한 요소로 사용되고 있다. W3C(World Wide Web Consortium)는 데이타 제공자가 자신이 방문한 웹 사이트에 개인정보를 제공하는 것을 통제할 수 있도록 하는 표준을 제시하였다. 그러나 데이타 수집 후 유통과정에서 개인정보에 대한 보안관리에 대한 언급이 없다. 현재 히포크라테스 데이타베이스(Hippocratic Databases), 사용목적기반 접근제어(Purpose Based Access Control)등은 W3C의 데이타 수집 메커니즘을 따르고 있으며, 데이타 수집 후 보안관리에 대하여 사용목적 관리와 접근제어 기법을 사용하여 관리를 하고 있으나 사용목적에 대한 표현과 사용목적 관리의 미흡함으로 인하여 그에 따르는 개인정보의 프라이버시 보호에 있어서 효과적인 해결책을 제시하지 못하고 있다. 본 논문은 사용목적의 표현력을 향상시키면서. 사용목적의 효과적인 관리기법을 제시한다. 또한 개인의 프라이버시 보호를 위한 방법으로 사용목적의 분류화를 통해 최소권한의 원칙을 따르는 접근제어 기법을 제시한다. 본 논문에서는 사용목적을 상속적, 시간적 그리고 독립적 구조로 분류화하였으며, 이렇게 분류화된 사용목적에 대한 각기 다른 관리기법을 제시한다. 또한 접근제어의 유연성을 위해 RBAC의 역할계층 구조를 사용하였으며, 일의 최소 단위인 태스크(task)의 최소권한을 얻기 위한 조건으로 몇몇 특성의 사용목적을 사용하여 만족할 경우 태스크를 처리하기 위한 기존 모델보다 향상된 최소사용권한을 제공하는 기법을 제시한다. Interference Contrast)에 의한 내부구조 관찰이 최종 동정기준이 되어야할 것으로 나타났다.cillus로 구성되었다. 한편, DAL세균군(42균주)은 high G+C 및 low G+C gram positive 계통군 이외에도 proteobacteria -subdivision에 속하는 Afipia와 Ralstonia, proteobacteria -subdivision에 속하는 Variovorax, proteobacteria $\beta$-subdivision에 속하는Pseudomonas로 구성되어 계통학적으로 다양한 세균임이 확인되었다. 40%까지 대체가 가능하였으며, 아울러 높은 라이신 부산물의 대체 수준에 있어서 사료효율과 단백질 전환효율을 고려한다면 아미노산 첨가(라이신과 아르지닌)와 중화 효과에 좋은 결과가 있을 것으로 사료된다.의한 적정 양성수용밀도는 각고 5~6cm 크기의 경우 10~15개체가 적합하였다. 수증별 성장은 15~20 m 수층에서 빨랐으며, 성장촉진과 폐사를 줄이기 위해서는 고수온이 지속되는 7~10월에는 20~30m수층으로 채롱을 내려 양성하고 그 외 시기에는 15 m층 내외가 좋은 것으로 나타났다. 상품으로 출하 가능한 크기 인 각고 10 cm이상, 전중량 140 g 내외로 성장시 키기까지는 채묘후 22개월이 소요되었고, 출하시기는 전중량 증가가 최대에 이르는 3월에서 4월 중순이 경제적일 것으로 판단된다.er 90 % of good relative dynamic modulus of elasticity due to fineness of formation caused by the

• Journal of the Korean Magnetics Society
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• v.17 no.1
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• pp.47-50
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• 2007

[ $ZnCr_2O_4$ ] shows geometrically frustrated magnet. Recently, $CoCr_2O_4$ has been investigated for multiferroic property and dielectric anomalies by spin-current model. Polycrystalline $CoCr_2O_4$ and $CoCrFeO_4$ compounds was prepared by wet-chemical process. Crystallographic and magnetic properties of $CoCr_2O_4$ and $CoCrFeO_4$ were investigate by using the x-ray diffractometer(XRD), vibrating sample magnetometer(VSM), superconducting quantum interference device magnetometer(SQUID), and $M\"{o}ssbauer$ spectroscopy. The crystal structure was found to be single-phase cubic spinel with space group of Fd3m. The lattice constants of $CoCr_2O_4$ and $CoCrFeO_4$ $a_0$ were determined to be 8.340 and 8.377 ${\AA}$, respectively. The ferrimagnetic transition temperature for the both samples were observed at 97 K and 320 K. The $M\"{o}ssbauer$ absorption spectra at 4.2 K show that the well developed two sextets are superposed with small difference of hyperfine field($H_{hf1}=507\;and\;H_{hf2}=492\;kOe$). Isomer shift values($\delta$) of the two sextets are found to be 0.33 and 0.34 mm/s relative to the Fe metal, respectively, which are consistent with the high spin $Fe^{3+}$ charge state.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7549-7554
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• 2015

The aim of this study was to develop gastric retentive bi-layered tablet using floating drug delivery technique. Metformin was selected as a model drug due to its narrow absorption window as well as very highly water solubility. These properties of metformin led to be difficult controlling the drug release. The bi-layered tablet was prepared with bi-layered compression machine to minimize interference between floating part and controlling part. The tablet weight, appearance and hardness were evaluated after compression process. The times of 'time to floating' and 'Floating duration' were tested for floating ability and drug release study was also carried out to understand drug release behavior. Furthermore, the drug release of bi-layered tablet was compared with marketed metformin tablet with sustained release pattern (Glucopharge XR$^{(R)}$).The floating ability and drug release behaviors were well controlled by changing amounts of $NaHCO_3$ (floating substance) and hydroxypropyl methylcellulose (HPMC; release control material). Bi-layered tablet had 13s of time to float, over 10h of floating duration and very similar drug release behavior compared with Glucopharge XR$^{(R)}$($f_2$: 89.6). Consequently, the bi-layered tablet with floating ability was successfully prepared and these properties can maximize the efficacy of metformin.

• Convergence Security Journal
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• v.18 no.1
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• pp.117-128
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• 2018

The purpose of this paper is to analyze the behavior of North Korea's cyber attack against South Korea since 2009 based on major international security theories and suggest South Korea's policy option. For this purpose, this paper applied the behavioral domain and characteristics of 'cyber power' and 'coercion dynamics' model, which are attracting attention in international security studies. The types of cyber attacks from North Korea are classified into the following categories: power-based incarceration, leadership attacks and intrusions, military operations interference, and social anxiety and confusion. In terms of types and means of cyber power, North Korean GPS disturbance, the Ministry of Defense server hacking and EMP are hard power with high retaliation and threat and cyber money cashing and ransomware are analyzed by force in the act of persuasion and incentive in the point of robbing or asking for a large amount of money with software pawns. North Korea 's cyber attack has the character of escape from realistic sanctions based on the second nuclear test. It is important for South Korea to clearly recognize that the aggressive cyberpower of North Korea is changing in its methods and capabilities, and to ensure that North Korea's actions result in far greater losses than can be achieved. To do this, it is necessary to strengthen the cyber security and competence to simultaneously attack and defend through institutional supplement and new establishment such as cyber psychological warfare, EMP attack preparation, and enhancement of security expertise against hacking.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.2
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• pp.29-39
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• 2021

The global aging phenomenon and new lifestyles have a worldwide attention to the new tourism form of health tourism. The purpose of this study is to analyze and suggest the competitive types of health tourism. Through the literature review, the theoretical base on the concept and type of health tourism and hierarchical spatial types such as medical space, semi-medical space, non-medical space, and natural healing space, based on medical intervention was established. A questionnaire survey was conducted for the professionals in Jeju area about tourism, health care, policy. As a result of analysis based on competitiveness advantage factors of Jeju health tourism, Jeju health tourism was confirmed to have higher importance in the natural healing space than the health service center space. Three kinds of resources such as natural resources, healing resources, and active resources of Jeju type health tourism were derived and applied to two hierarchical spaces, natural healing space and non-medical healing space, based on medical intervention.