• Journal of Navigation and Port Research
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• v.26 no.1
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• pp.146-151
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• 2002

Efficiency of dredging work depends on the types of equipment used, the sediments encountered, whether the work to be performed is new or for maintenance, pre and/or post hydrographic surveying and so forth. Among those, surveying accuracy which is directly determined by the control of the dredge's position and depth surveying accuracy being surveyed at the dredging point are important factors. The purpose of this study is to develop an integrated process management system for pump dredge. The system is composed of 4 sub-systems such as LADGPS for dredge positioning dredging point determination, tidal gauge and angular depth sensor for depth determination, and GIS and ENC process management. The process management system for pump dredge developed was installed on the pump dredge "EUNJIN PD-2" but is now producing work data for comparison with performance of the existing dredge. The data retrieved from the pump dredge process management system up to now shows similar result from the grab dredge management system which was developed previously. It is easy to operate, achieves good accuracy with only 45cm unevenness, reduces working perioa by 20 percint,. More precise evaluation of the system comes later after the dredging work is completed.completed.

• Applied Microscopy
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• v.40 no.4
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• pp.177-183
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• 2010

A focused ion beam (FIB) system produces a beam of positive ions (usually gallium) which are heavier than electrons and can be focused by electrostatic lenses into a spot on the specimen. With its ability milling of the specimen material by 10 to 100 nm with each pass of the beam, FIB is widely adopted in materials science, semiconductor industry, and ceramics research. Recently, FIB has been increasingly employed in the field of biomedical sciences. Here we provide a brief introduction to FIB and its applications for a wide variety of biomedical research. The surface of specimen can be in situ processed and quasi-real time visualized by two beam combination of FIB and field emission scanning electron microscope (FESEM). Due to its milling process, internal structures can be exposed and analyzed: yeast cells, fungus-inoculated wheat leaf, mannitol particles in inhalation aerosols, and oyster shell. Serial blockface tomography with the system kindles 3-dimensional reconstruction researches in the realm of nervous system and life sciences. Two-beam system of FIB/FESEM is a versatile tool to be utilized in the biomedical sciences, especially in 3-dimensional reconstruction studies.

• Geophysics and Geophysical Exploration
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• v.20 no.2
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• pp.100-113
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• 2017

Induced polarization (IP) method is based on the measurement of a polarization effect known as overvoltage of the ground. IP techniques have been usually used to find mineral deposits, however, nowadays widely applied to hydrogeological investigations, surveys of groundwater pollution and foundation studies on construction sites. IP surveys can be classified by its source type, i.e., time-domain IP estimating chargeability, frequency-domain IP measuring frequency effect (FE), and complex resistivity (CR) and spectral IP (SIP) measuring complex resistivity. Recently, electromagnetic-based IP has been studied to avoid the requirement for spike electrodes to be placed in the ground. In order to understand IP methods in this study, we: 1) classify IP surveys by source type and measured data and illustrate their basic theories, 2) describe historical development of each IP forward modeling and inversion algorithm, and finally 3) introduce various case studies of IP measurements.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.148.1-148
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• 2003

버섯은 균사체와 자실체를 가진 고등균류로서 옛날부터 식용은 물론 약용으로 많이 사용되어 왔으며 부작용이 없는 저칼로리 식품으로서, 영양적인 측면과 의약품으로서의 효능을 가진 식품으로 인식되어 소비량이 날로 증가하는 추세이다. 버섯은 항균자용, 항암작용, 면역증강작용, 혈압강하 효과 및 혈중 콜레스테롤합성 억제효과 등의 다양한 생리활성을 나타내고 있어 국내에서도 버섯의 균사체 배양이 활기를 띄고 있다. 본 연구에서는 5종류의 버섯(아가리쿠스, 상황, 노루궁뎅이, 운지, 동충하초)의 균사체 배양원액을 10%, 30%, 50%, 100% 함유한 음료로서 전자공여능, 아질산염소거능, MDA cell과 A549 cell에 대한 암세포 증식억제 작용을 조사하였다. 5종류의 버섯 균사체 음료의 전자공여능은 발효원액을 30% 함유한 경우에 72∼89%였으며 100% 원액의 경우는 87∼93%의 탁월한 항산화능을 나타내었다. 균사체 음료의 아질산염 소거능은 노루궁뎅이버섯이 가장 높아서 균사체 원액은 73%, 112 희석액은 51%였으며 다음은 동충하초의 균사체 원액이 52%를 나타내었고 나머지 3종류의 버섯 균사체는 28∼36%의 아질산염소거능을 나타내었다. 균사체 발효음료 원액은 MBA cell에 대하여 5종류의 버섯 모두에서 82∼85%의 높은 암세포 증식억제작용을 나타내었고 동충하초는 1/2 희석액에서도 80%이상의 증식억제활성을 나타내었다. 균사체 발효음료 원액의 A549 cell에 대한 증식억제능은 동충하초 발효원액이 68%, 상황 발효원액이 50%로서 MDA cell에 대한 증식억제효과 보다는 효능이 낮은 편이었다. 전체적으로 5종류의 버섯 균사체 발효음료는 항산화작용, 아질산염소거능, 항암활성이 우수한 기능성 음료로 활용될 수 있을 것으로 생각된다.적으로 평가하는데 적합하나 아직 국내에선 X-선을 이용한 가공용 감자의 내부 결함특성에 대한 연구는 이뤄지지 않고 있다. 이에 본 연구에서는 가공용 감자의 내부결함 특성중 하나인 내부동공의 X-선에 의한 특성을 본 연구소에 있는 X-선 발생장비로 측정해 보고 비파괴적인 방법으로 실시간 가능성을 시험하였다. 감자는 수원 농산물 도매시장에서 2003년산 가공용 감자 (품종:선농)를 구매하여 사용하였다. 감자내 내부동공은 35 ∼ 40 kV와 5.25 mA값으로 발생된 X-선에 의해 잘 검출되는 것으로 나타나, 현장에서 충분히 활용가능 할 것으로 판단되었다. 금후, 실시간으로 내부동공을 검출할 수 있는 시스템을 개발할 계획이다.정한 결과 메탄올에서는 5% 농도차이가 그 추출효율에 유의적인 영향을 주지 않는 것으로 나타났다. 에탄올에서는 40%에서 가장 높은 함량이 측정되었고 아세톤에서는 50%에서 측정되었다. 따라서 시료의 상태와 상관없이 배 과피의 페놀성물질 추출용매로는 40∼70%의 함수 아세톤이 적합한 것으로 사료된다.en delicious는 상온에서60일 동안 보관하였을 경우, 사과표피의 색도 변화를 현저히 지연시킴을 확인하였다. 또한 control과 비교하여 성공적으로 사과에 코팅하였으며, 상온에서 보관하여을 때 사과의 품질을 30일 이상 연장하는 효과를 관찰하였다. 이들 결과로부터 대두단백질 필름이 과일 등의 포장제로서 이용할 가능성을 확인하였다.로 [-wh] 겹의문사는 복수 의미를 지닐 수 없 다. 그러면 단수 의미는 어떻게 생성되는가\ulcorner 본 논문에서는 표면적 형태에도 불구하고 [-wh]의미의 겹의문사는 병렬적 관계의 합성어가 아니라 내부구조를 지니지 않은 단순한 단어(minimal $X^{0}$ elements

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.5
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• pp.345-353
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• 2003

When designing network processors or implementing network equipments such as routers are implemented, IP lookup operations cause the major impact on their performance. As the organization of the IP address becomes simpler, the speed of the IP lookup operations can go faster. However, since the efficient management of IP address is inevitable due to the increasing number of network users, the address organization should become more complex. Therefore, for both IPv4(IP version 4) and IPv6(IP version 6), it is the essential fact that IP lookup operations are difficult and tedious. Lots of researcher for improving the performance of IP lookups have been presented, but the good solution has not been came out. Software approach alleviates the memory usage, but at the same time it si slow in terms of searching speed when performing an IP lookup. Hardware approach, on the other hand, is fast, however, it has disadvantages of producing hardware overheads and high memory usage. In this paper, conventional researches on IP lookups are shown and their advantages and disadvantages are explained. In addition, by mixing two representative structures, a new hybrid parallel architecture for fast IP lookups is proposed. The performance evaluation result shows that the proposed architecture provides better performance and lesser memory usage.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.7
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• pp.486-493
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• 2003

Schottky type A $l_{0.33}$G $a_{0.67}$N ultraviolet photodetectors were fabricated on the MOCVD grown AlGaN/ $n^{＋}$-GaN and AlGaN/AlGaN interlayer/ $n^{＋}$-GaN structures. The grown layers have the carrier concentrations of -$10^{18}$, and the mobilities were 236 and 269 $\textrm{cm}^2$/V.s, respectively. After mesa etching by ICP etching system, the Si3N4 layer was deposited for passivation between the contacts and Ti/AL/Ni/Au and Pt were deposited for ohmic and Schottky contact, respectively. The fabricated Pt/A $l_{0.33}$G $a_{0.67}$N Schottky diode revealed a leakage current of 1 nA for samples with interlayer and 0.1$\mu\textrm{A}$ for samples without interlayer at a reverse bias of -5 V. In optical measurement, the Pt/A $l_{0.33}$G $a_{0.67}$N diode with interlayer showed a cut-off wavelength of 300 nm, a prominent responsivity of 0.15 A/W at 280 nm and a UV-visible extinction ratio of 1.5x$10^4./TEX>.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.6
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• pp.126-134
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• 2015

A sleep disorder is being recognized as one of the major health issues related to high levels of stress. At the same time, interests about quality of sleep are rapidly increasing. However, diagnosing sleep disorder is not a simple task because patients should undergo polysomnography test, which requires a long time and high cost. To solve this problem, an accelerometer embedded wrist-worn device is being considered as a simple and low cost solution. However, conventional methods determine a state of user to "sleep" or "wake" according to whether values of individual section's accelerometer data exceed a certain threshold or not. As a result, a high miss-classification rate is observed due to user's intermittent movements while sleeping and tiny movements while awake. In this paper, we propose a novel method that resolves the above problems by employing a dynamic classifier which evaluates a similarity between the neighboring data scores obtained from SVM classifier. A performance of the proposed method is evaluated using 50 data sets and its superiority is verified by achieving 88.9% accuracy, 88.9% sensitivity, and 88.5% specificity.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.7
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• pp.1777-1783
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• 2014

In this paper, we designed and fabricated a high-speed semiconductor sensor for use in power control devices and analyzed the characteristics with pulsed radiation tests. At first, radiation sensitive circular Si PIN diodes with various diameters(0.1 mm ~5.0 mm) were designed and fabricated using Si epitaxial wafer, which has a $42{\mu}m$ thick intrinsic layer. The reverse leakage current of the diode with a radius of 2 mm at a reverse bias of 30 V was about 20.4 nA. To investigate the characteristic responses of the developed diodes, the pulsed gamma-radiation tests were performed with the intensity of 4.88E8 rad(Si)/sec. From the test results showing that the output currents and the rising speeds have a linear relationship with the area of the sensors, we decided that the optimal condition took place at a 2 mm diameter. Next, for the selected 2 mm diodes, dose rate tests with a range of 2.47E8 rad(Si)/sec to 6.21E8 rad(Si)/sec were performed. From the results, which showed linear characteristics with the radiation intensity, a large amount of photocurrent over 60mA, and a high speed response under 350ns without saturation, we can conclude that the our developed PIN diode can be a good candidate for the sensor of power control devices.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.5
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• pp.673-681
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• 2011

Among the network information services combined with a number of security technologies and required security policies, Infrastructure as a Service, a hardware plat-form service of Cloud Computing, has been provided since 2011. It is more or less similar to the existing central concentration method services, in terms of the specifications and technical aspects for given hardware category, but it is entirely different from them in that it overcomes the spatial limitations of specific network and targets the public network. Information security technology has also been prospering so that it could ensure the stability of offered hardware plat-forms. As currently supported hardware, Internet Data Center has been provided by virtualizing the previously offered servers and discs (backup discs), but the hardware plat-forms offered are somewhat limited. Meanwhile, the areas of security fields for offered services are confined to the center or include the TCP/IP-based SSL (Secure Sockets Layer) for the public network connected with clients, which shows that microscopic access security policies have been used. Therefore, this study was aimed to provide a realistic security mechanism for realizing defense policy, by expanding service areas into security devices and suggesting Diskless and Stateless security policy based high-speed synchronous network infrastructure.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.7 s.349
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• pp.93-103
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• 2006

Network solutions for protecting against worm attacks that complement partial end system patch deployment is a pressing problem. In the content-based worm filtering, the challenges focus on the detection accuracy and its performance enhancement problem. We present a worm filter architecture using the bloom filter for deployment at high-speed transit points on the Internet, including firewalls and gateways. Content-based packet filtering at multi-gigabit line rates, in general, is a challenging problem due to the signature explosion problem that curtails performance. We show that for worm malware, in particular, buffer overflow worms which comprise a large segment of recent outbreaks, scalable -- accurate, cut-through, and extensible -- filtering performance is feasible. We demonstrate the efficacy of the design by implementing it on an Intel IXP network processor platform with gigabit interfaces. We benchmark the worm filter network appliance on a suite of current/past worms, showing multi-gigabit line speed filtering prowess with minimal footprint on end-to-end network performance.