• Investigative Magnetic Resonance Imaging
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• v.4 no.1
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• pp.7-13
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• 2000

Purpose : To assess the distortion of MRI with the Leksell stereotactic radiosurgery system in variable pulse sequence and imaging plane through phantom study, to find most adequate imaging plane and pulse sequence for stereotactic radiosurgery system. Materials and methods : We made the phantoms for MRI and get images in variable conditions and analyzed the image distortion using image analysis program, and statistically using paired student t-test. Results : The transeverse plane images had acceptable error ranges bless than 1.5mm) in all pulse sequence in both the analysis of fiducial marker in stereotactic G-frame and the phantom study. The coronal plane images had unacceptable large errors (more than 1.7mm) in the analysis of fiducial marker in the stereotactic G-frame, but had corrected small errors (less than 1.5mm) in the phantom study. Conclusion : We find from the phantom study that the present MR machines are adequate for stereotactic surgery system in frequently used pulse sequences, and imaging planes.

• Journal of Internet Computing and Services
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• v.21 no.1
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• pp.179-190
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• 2020

In the Unix-like system environment, the GOT overwrite attack is one of the traditional control flow hijacking techniques for exploiting software privileges. Several techniques have been proposed to defend against the GOT overwrite attack, and among them, the Full Relro(Relocation Read only) technique, which blocks GOT overwrites at runtime by arranging the GOT section as read-only in the program startup, has been known as the most effective defense technique. However, it entails loading delay, which limits its application to a program sensitive to startup performance, and it is not currently applied to the library due to problems including a chain loading delay problem caused by nested library dependency. Also, many compilers, including LLVM, do not apply the Full Relro technique by default, so runtime programs are still vulnerable to GOT attacks. In this paper, we propose a GOT protection scheme using the Control Flow Integrity(CFI) technique, which is currently recognized as the most suitable technique for defense against code reuse attacks. We implemented this scheme based on LLVM and applied it to the binutils-gdb program group to evaluate security, performance and compatibility. The GOT protection scheme with CFI is difficult to bypass, fast, and compatible with existing library programs.

• Korean Journal of Ecology and Environment
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• v.46 no.4
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• pp.581-587
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• 2013

The amounts of carbon (C), nitrogen (N) and phosphorus (P) in relation to dry weight (D.W.) were measured in zooplankton from the large four rivers (Han R., Geum R., Yeongsan R. and Seomjin R.) during 2004~2008. The stoichiometry of total zooplankton in four river systems was highly variable. The ranges of average C, N and P-contents were $70{\sim}620mgC\;mg^{-1}$ D.W., $7.1{\sim}85.5{\mu}gN\;mg^{-1}$ D.W. and $2.5{\sim}7.4{\mu}gP\;mg^{-1}$ D.W., respectively. The mean C :N: P atomic ratios reflected large spatial differences. The C : P and N : P ratios of the zooplankton community ranged from 38 to 392 : 1 and from 4 to 65 : 1 in all sampling sites. Self-Organizing Map (SOM) was applied to the survey data, and the study sites were clearly classified into 3 clusters. Clustering was largely affected by the distribution pattern of C, N, P-contents, which is related with characteristics of river systems on the basis of stoichiometry.

• Journal of Animal Environmental Science
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• v.8 no.3
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• pp.199-208
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• 2002

This paper introduces the method to make management network about milking cow farm tasks. The object of this research was to design of biological measuring system and managing network system in a livestock farm. This auto-management system provides informations about individual cows' temperature, conductivity of milk and weight for efficient management of feeding, and milking works by a micro-processor and RS -485 type serial COM. ports. And measured bio-data which are basic informations for remote raising management are saved to user PC by serial communication between the PLC and user PC. Milking cow farm is divided into three working place to each measurement work and feed. The first working place is milking station which has two thermometers, a conduct meter and a scale set. The second working place is feeding station, and the third place is cattle cage. These are combined by network system and the PLC which is used to drive network and sub-modules. Sub-modules have a micro-process to control the sensor and to interface with network. The PLC which drive network and control sequence has two serial communication port to be linked with user PC for sending the measured data and for receiving data. Above all, in this study tells the sequence operating method by the driving scenario of breeding milk cow for livestock auto-management using the PLC and network system.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.3
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• pp.26-31
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• 2009

A new LFSR based test compression scheme is proposed by reducing the maximum number of specified bits in the test cube set, smax, virtually. The performance of a conventional LFSR reseeding scheme highly depends on smax. In this paper, by using different clock frequencies between an LFSR and scan chains, and grouping the scan cells, we could reduce smax virtually. H the clock frequency which is slower than the clock frequency for the scan chain by n times is used for LFSR, successive n scan cells are filled with the same data; such that the number of specified bits can be reduced with an efficient grouping of scan cells. Since the efficiency of the proposed scheme depends on the grouping mechanism, a new graph-based scan cell grouping heuristic has been proposed. The simulation results on the largest ISCAS 89 benchmark circuit show that the proposed scheme requires less memory storage with significantly smaller area overhead compared to the previous test compression schemes.

• Journal of the Korea Society for Simulation
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• v.16 no.2
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• pp.27-35
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• 2007

When sensor networks are deployed in open environments, all the sensor nodes are vulnerable to physical threat. An attacker can physically capture a sensor node and obtain the security information including the keys used for data authentication. An attacker can easily inject false reports into the sensor network through the compromised node. False report can lead to not only false alarms but also the depletion of limited energy resource in battery powered sensor networks. To overcome this threat, Fan Ye et al. proposed that statistical on-route filtering scheme(SEF) can do verify the false report during the forwarding process. In this scheme, the choice of a security threshold value is important since it trades off detection power and energy, where security threshold value is the number of message authentication code for verification of false report. In this paper, we propose a fuzzy rule-based system for security threshold determination that can conserve energy, while it provides sufficient detection power in the SEF based sensor networks. The fuzzy logic determines a security threshold by considering the probability of a node having non-compromised keys, the number of compromised partitions, and the remaining energy of nodes. The fuzzy based threshold value can conserve energy, while it provides sufficient detection power.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.106-106
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• 2002

미토콘드리아는 세포내의 에너지대사에서 중요한 역할을 수행하는 세포내 소기관이며, 자체의 유전물질이 모계를 통해 유전되는 특징을 가지고 있다. 포유류 초기 배아의 발생과정에서 미토콘드리아의 역할과 기능에 대한 연구는 미진한 상태이다. 본 연구에서는 생쥐 초기 배아의 발생과정에서 관찰할 수 있는 미토콘드리아 미세구조의 변화 양상을 살펴보고, 이와 초기 배아의 발생 능력과의 관련성을 밝혀보고자 하였다. 과배란 유도된 ICR 생쥐로부터 배란된 난자와 2-세포기 배아를 수획하여 76 배양액으로 포배기까지 체외배양하면서, 각각의 발생단계에 따라 시료를 수획하였다. 미토콘드리아 미세구조의 변화는 일반적인 투과전자현미경방법(TEM)을 이용하여 관찰하였다. 미토콘드리아의 미세구조는 배란 난자에서 4-세포기 배아까지는 구형이고 크리스타가 발달하지 않은 원시형태였지만, 포배기로 발달함에 따라 크리스타가 발달된 막대형의 전형적인 미토콘드리아로 분화됨이 관찰되었다. 체외배양 중에 발생이 지연되거나 정지된 배아에서 관찰한 미토콘드리아의 미세구조는 공포화 (vacuolization), 크리스타 발달 지연, 손상된 미토콘드리아의 세포막 등과 같은 비정상적인 변형을 관찰할 수 있었다. 또한, 극체에 존재하는 미토콘드리아의 미세구조는 정상적인 핵내의 유전자와의 상호작용이 없어 미분화 상태로 포배기까지 유지되는 것을 관찰하였다. 이상의 결과를 통해 미토콘드리아의 정상적인 분화 과정이 초기 배아의 발생능력과 관련되어 있음을 알 수 있었으며, 포유류 초기 배아의 체외배양시스템을 개선하는데 미토콘드리아 미세구조의 관찰과 변화에 대한 고려가 있어야 될 것으로 생각된다. buffer A 용액으로 세척하여 유리 petri dish의 바닥에 부착된 macrophage만을 cell scraper로 분리하였다. 분리한 macrophage는 0.5-1 $\times$ $10^{6}$ cells/$m\ell$가 되게 조정하여, IL-I 을 0.001, 0.01, 0.1 또한 1 ng/$m\ell$를 첨가하여 농도에 따른 효과를 조사하였고, 각각 24, 48, 72, 96 또한 120시간을 배양하여 시간에 의한 효과도 실시하였다. 각 배치구에서 얻어진 배양액은 TGF-$\beta$를 조사하기 전까지 -2$0^{\circ}C$에 동결 보존하였다. TGF-$\beta$의 측정은 TGF-$\beta$ kit(promega, USA)를 이용하여 실시하였으며, 통계학적 분석은 Anova test를 Statview program을 이용하여 분석하였다. 시험의 결과 대조구에 비해 IL-I 첨가구는 2-3배의 TGF-$\beta$생산을 보였으며, 배양시간에 따른 생산은 시간이 지남에 따라 약간 상승하는 경향을 보였으나, 유의적인 차이를 보이지는 않았다. 또한 IL-I의 농도에 따른 생산의 변화는 IL-I의 농도에 따라 약간의 차이를 보였고 유의적인 차이는 인정되지 않았다. 임신 및 비임신의 경우 임신우의 비장 macrophage가 비임신보다는 약간 상승하는 거스로 나타났다. 이상의 결과로 볼 때 IL-I $\alpha$ 는$\bet

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.8
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• pp.117-125
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• 2015

In this paper, we propose a classification algorithm based on the obtained EEG(Electroencephalogram) signal for the control of 'left' and 'right' turnings of which a driving system composed of EEG sensor, Labview, DAQ, Matlab and driving robot. The proposed algorithm uses features extracted from frequency band information obtained by DWT (Discrete Wavelet Transform) and selects features of high discrimination by using Fisher score. We, also propose the number of feature vectors for the best classification performance by using SVM(Support Vector Machine) classifier and propose a decision pending algorithm based on MLD (Maximum Likelihood Decision) to prevent malfunction due to misclassification. The selected four feature vectors for the proposed algorithm are the mean of absolute value of voltage and the standard deviation of d5(2-4Hz) and d2(16-32Hz) frequency bands of P8 channel according to the international standard electrode placement method. By using the SVM classifier, we obtained 98.75% accuracy and 1.25% error rate. Also, when we specify error probability of 70% for decision pending, we obtained 95.63% accuracy and 0% error rate by using the proposed decision pending algorithm.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.10
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• pp.758-765
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• 2018

This paper presents a 24-GHz frequency-modulated continuous wave(FMCW) radar transceiver with two Rx and one Tx channels in 65-nm complementary metal-oxide-semiconductor(CMOS) process and implemented it on a radar system using the developed transceiver chip. The transceiver chip includes a $14{\times}$ frequency multiplier, low-noise amplifier, down-conversion mixer, and power amplifier(PA). The transmitter achieves >10 dBm output power from 23.8 to 24.36 GHz and the phase noise is -97.3 GHz/Hz at a 1-MHz offset. The receiver achieves 25.2 dB conversion gain and output $P_{1dB}$ of -31.7 dBm. The transceiver consumes 295 mW of power and occupies an area of $1.63{\times}1.6mm^2$. The radar system is fabricated on a low-loss Duroid printed circuit board(PCB) stacked on the low-cost FR4 PCBs. The chip and antenna are placed on the Duroid PCB with interconnects and bias, gain blocks and FMCW signal-generating circuitry are mounted on the FR4 PCB. The transmit antenna is a $4{\times}4$ patch array with 14.76 dBi gain and receiving antennas are two $4{\times}2$ patch antennas with a gain of 11.77 dBi. The operation of the radar is evaluated and confirmed by detecting the range and azimuthal angle of the corner reflectors.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.2
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• pp.357-368
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• 2018

For well over 100 years, oil has enabled remote communities to generate electricity and enjoy the benefits of a consistent electrical supply. Relying solely on oil for electricity generation has left island and remote communities exposed to several risks and drawbacks. Oil-based electricity generation is often more expensive and subject to price volatility, which can result in the use of risky fuel hedging strategies. The residents of islands and remote communities express concern over the future impacts of climate change or insist on their opinions for the corresponding action with reduction of carbon emissions. These risks and drawbacks can be overcomed with continuing cost reductions in solar, wind, and energy storage technologies by maker. Reducing costs is not always a straightforward process, relying on more diversely and renewably arranged renewable energy sources led to reduced local construction cost in every situation reviewed in this study. In this paper, a convenient and simple design solution which will facilitate the optimum location and transmission route of renewable energy facility using GIS(Geographic Information System) is proposed. The suggested solutions exercised to the case of geomoon island using GIS and identified by local site survey.