• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.2
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• pp.37-44
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• 2004

In this paper, we performed the design and the development of the wide-band correlation board to be an important role in the autocorrelation spectrometer's building for the observation study of an extra-galaxy's spectral lines and the survey research of the special radio sources in field of the radio astronomy. In this research, the developed correlation board by using QUAINT correlator chip(made by NRAO) has maximum 100 MHz clock speed and operate at a intermediate frequency with 400 MHz bandwidth. For the Performance test we supply the 0.5 and 1.67 MHz rectangular wave, then we obtain the autocorrelation coefficients. The final results, which process by using FFT, get the almost same results compare with the theoretical correlation.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.8
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• pp.1165-1171
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• 2010

The OFDM system has better characteristics in transmission rate, power efficiency, bandwidth efficiency, impulse-noise immunity, and narrow band interference immunity etc. in comparison with other conventional systems. However, high PAPR of an OFDM signals causes some serious non-linear processing of RF amplifier. And performance of the communication system gets worse. Therefore, various methods reducing PAPR of an OFDM skills such as the clipping method, block coding method, and phase rotation method etc. have been researched. In this paper, we propose a high-speed adaptive PTS method which eliminates high PAPR. And we compare the proposed method with other conventional methods. The proposed method has decreased quantity of calculation compare with an adaptive PTS method. Of course, The more its calculation amount is decreased, the more its BER characteristic is not better than an adaptive PTS method. However, keeping up satisfactory BER performance, we highly improved calculation amount of a PTS method.

• Journal of Navigation and Port Research
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• v.34 no.10
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• pp.775-780
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• 2010

In the machinery, the brake system is as important part as machine's working. The situation of emergency stop, the machine doesn't stopped would be occur big accident. This is common things for all of machinery, also for the ships. There are two kind of mooring devices are existed on the ship. One of them, the windlass winch, is used to anchor. The other, the mooring winch is used to moor the ship in pier use the rope tied to bitt on dock. In case of previously been used mooring winch made of a steel plate, and the bolt which was connect brake band and lining broken. In this study, prevent an accident find the position of stress concentration by finite element analysis program. And removed stress concentration. And search the optimum position of the separation angle to be more efficient.

• KIISE Transactions on Computing Practices
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• v.22 no.9
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• pp.405-418
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• 2016

Recently, many researchers have studied the VSL decision method using traffic information in multiple detector zones. However, this method selects incorrect VSL starting points, leading to the selection of the wrong speed control zone and calculation of the wrong VSL, causing traffic congestion. Eventually, the Unstable VSL system causes more congestion on the freeway. This paper proposes an improved VSL algorithm stably operated in multiple detector zones on the Korea highway. The proposed algorithm selects a preliminary VSL start station (VSS) expected to end the congestion using the acceleration of stations. It also determines the VSS at each congestion area. Finally, it calculates the VSL relative to the determined VSS and controls the vehicles that enters the traffic congestion zone. The developed strategy is compared with Real-time Variable Speed Limits for Urban Freeway (RVSL) to test the stability and efficiency of the proposed algorithm. The results show that the proposed algorithm resolves the problems of the existing algorithm, demonstrated by the correct VSS decision and the reduction of total travel time by 1-2 minutes.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.4
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• pp.341-351
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• 2008

Communication in wireless sensor networks comprising a plurality of sensor nodes located in an ad hoc environment is unidirectional in that data gathered by sensor nodes are transmitted to a sink node and not vice versa. In those networks, it is not possible for a server or a gateway to send commands to the sensor nodes to determine whether some previously received data are valid when the data indicate unusual conditions, which makes it difficult to make appropriate reactions to the unusual situations. This paper proposes and implements a TDMA-based sensor network communication protocol named BiWSLP(Bidirectional Wireless Sensor Line Protocol) supporting bidirectional communication capability. The BiWSLP is an extension of the WSLP, a unidirectional sensor network communication protocol based on the TDMA protocol. To test the feasibility of the proposed BiWSLP, we construct a virtual bridge management system capable of sending commands to sensor nodes as well as collecting data from the sensor nodes. Based on the test results of the virtual bridge management system, we show the applicability and advantages of the BiWSLP in terms of energy efficiency and bidirectional communication capability.

• Journal of Broadcast Engineering
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• v.8 no.1
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• pp.91-100
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• 2003

In this paper, to improve the retrieval Performance, an efficient combination of the MPEG-7 visual descriptors, such as the edge histogram descriptor (EHD), the color layout descriptor (CLD), and the homogeneous texture descriptor (HTD), is proposed in the framework of the relevance feedback approach. The EHD represents spatial distribution of edges in local image regions and it is considered as an important feature to represent the content of the image. The CLD specifies spatial distribution of colors and is widely used in image retrieval due to its simplicity and fast operation speed. The HTD describes precise statistical distribution of the image texture. Both the feature vector for the query image and the weighting factors among the combined descriptors are adaptively determined during the relevance feedback. Experimental results show that the proposed method improves the retrieval performance significantly tot natural images.

• 대한근관절건강학회:학술대회논문집
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• 2002.11a
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• pp.238-246
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• 2002

최근 경제의 발전과 의학의 발달로 인하여 인간의 수명은 점차 연장됨에 따라, 노인인구도 급격히 증가하고 있다. 40세 이상 여성 인구도 8.998천명으로 전체 여성의 38%를 차지하며 이는 매년 증가할 것이다. 그리하여 전체 인구에 대한 폐경 여성의 점유율도 급격히 증가하고 있다. 폐경 이후 $5{\sim}10$년 동안 매년 $2{\sim}4%$씩 골농도가 감소하고 있기 때문에 폐경기 여성을 위협하는 주요 질환 중 하나가 골다공증이다. 하지만 골다공증은 뚜렷한 자각증상이 없어 골 기형 및 골절이 발생하기 전에는 조기발견이 어렵다. 골다공증은 모든 중년 여성의 건강문제이므로 지역사회에서 골절 발생 위험율을 줄일 수 있도록 골다공증 예방을 위한 건강관리가 필요하다. 본 연구의 목적은 지역사회에서 적용할 수 있는 골다공증 예방 프로그램을 개발하여 그 효과를 검정한 후 지역사회 중년 여성 건강증진 프로그램으로 활용코저 함에 있다. 골다공증 예방 프로그램은 운동과 교육으로 구성하였으며, 12주 동안 점핑 동작 위주의 에어로빅과 스텝퍼 운동과 근력강화운동(최대 심박수의 $70%{\sim}80%$, $70{\sim}80$분, 3회/주)을 병행하여 실시하였고, 교육은 운동과 칼슘 섭취의 중요성을 건강 신념 이론에 근거하여 자기 효능감을 증대시키는 교육을 하여 지속적인 운동 실천과 칼슘식이 섭취를 하도록 하였다. 대상자는 서울시 일개 보건소에서 골감소증으로 진단받은 폐경 여성으로 실험군 19명과 대조군 19명이었다. 골다공증 예방 프로그램의 효과는 골밀도, DPD ratio, osteocalcin, 일일 평균 칼슘섭취량, 일일 열량 소모량, 배근력, 최대 산소 섭취량, 제지방량과 건강신념 변수로 측정하였다. 수집된 자료는 PC SPSS 8.0 프로그램을 이용하여 대상자의 일반적 특성은 실수와 백분율로 실험군과 대조군의 동질성 검사는 t-test, $x^2-test$ 및 Fisher exact test를 이용하였고, 두 집단 간 결과변수들의 중재 전후의 차이는 t-test로 분석하였다. 연구 결과는 다음과 같다. 1) $L_{2-4}$ 골밀도는 실험군이 대조군에 비하여 유의하게 높았다. 2) DPD ratio와 osteocalcin은 두 집단간 유의한 차이가 없었다. 3) 배근력은 실험군에서 대조군보다 유의하게 증가하였으나, 제지방량과 최대 산소 섭취량은 유의한 차이가 없었다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.1
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• pp.19-26
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• 1970

During the summer of 1969, a series of experiments on the spawning and development of the eggs of grass carp and silver carp was performed with the following results, but the complete development of eggs Iras not accomplished: 1. The season of maturity for both species is estimated to be from the end of June to the beginning of August. 2. Pituitary glands for the use of inducing maturation should be obtained before the maturation season of its donor. 3. Silver carp as small as 40 cm in body length (48 cm in total length) with an age of 6 years were found to have reached maturity, and the number of eggs in the ovaries were from about 23 to 26 thousand for those with body lengths of 40-44.5 cm. 4. The conical-shaped net cloth incubator worked better than others, and each incubator was most effective when installed in parallel series to the water supply pipe with a valve for each incubator to control water flow. 5. During the egg development, if any cell or cells were displaced, the eggs eventually died. 6. The proper manipulation of brood fish before the egg-taking seems to be very Important, and close care should be paid to feeding them well and keeping them in a pond of proper water depth.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.2
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• pp.123-130
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• 2016

In this paper, a novel flexible microfluidic metamaterial absorber is proposed for remote chemical sensor applications. The proposed metamaterial absorber consists of a periodic of split-ring-cross resonators(SRCRs) and a microfluidic channel. The SRCR patterns are inkjet-printed using silver nanoparticle inks on paper. The microfluidic channels are laser-etched on polydimethylsiloxane(PDMS) material. The proposed absorber can detect change of the effective permittivity at different liquids. Therefore, the absorber can be used for a remote chemical sensor by detecting change of the resonant frequencies. The performance of the proposed absorber is demonstrated with full-wave simulation and measurement results. The experimental results shows that the resonant frequency is 10.49 GHz at the empty channel. When ethanol and DI-water are injected into the channel, the resonant frequencies are 10.04 GHz and 8.9 GHz, respectively.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.3
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• pp.53-61
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• 2006

This paper is proposed adaptive fuzzy-neuro controller for high performance of induction motor drive. The design of this algorithm based on fuzzy-neural network controller that is implemented using fuzzy control and neural network. This controller uses fuzzy nile as training patterns of a neural network. Also, this controller uses the back-propagation method to adjust the weights between the neurons of neural network in order to minimize the error between the command output and actual output. A model reference adaptive scheme is proposed in which the adaptation mechanism is executed by fuzzy logic based on the error and change of error measured between the motor speed and output of a reference model. The control performance of the adaptive fuzzy-neuro controller is evaluated by analysis for various operating conditions. The results of experiment prove that the proposed control system has strong high performance and robustness to parameter variation, and steady-state accuracy and transient response.