• Journal of Biomedical Engineering Research
• /
• v.17 no.1
• /
• pp.19-24
• /
• 1996

The purpose of this paper is to design high-order (or radial) surface gradient coil (SGC), which can provide multi-dimensional spatial selection. Although the spatial Selection with High-Order gradienT (SHOT) can provide a 2-D selection with only one selective RF pulse, the high-order gradient pro- duced by conventional cylindrical-shape coils has not been clinically useful due to the large selection size caused by the limited radial gradient intensity. However, by using the proposed high-order SGCs located near the imaging region, the size of volume selection can be reduced to a clinically useflll size of 1-2 cm in diameter by applying stronger radial gradient field with much less gradient driving power. So far radial SGCs have been designed by using the field component method and may cause distortion in the selection shapes. In this paper, by using the target field approach for the coil design, selected volumes became almost circular. A 40 cm-by-40 cm $z^2$_surface gradient coil has been designed and implemented by using the target field approach. Phantom and volunteer studies have been performed Experimental results using spatially localized MRI show good agreement to the theoretically predicted behavior.

• The Journal of the Korea Contents Association
• /
• v.14 no.5
• /
• pp.1-7
• /
• 2014

Nowadays hospitals have been improving their job performances through informatization and also establishing an advanced, integrated medical information system through their manager's decision making support system in order to play roles as a hub hospital providing high quality medical services integrated with ICT technology. This study connects the OCS system and HIS system to the integrated medical information system to design an optimized, customized mobile health care and medical treatment environment and also investigates the systematic medical system that can perform patients' cure and medical treatment promptly and accurately in order to maximize convenience of treatment by inquiring into patients' information and information of medical treatment promptly.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38A no.1
• /
• pp.26-32
• /
• 2013

Blind algorithms based on Information potential of output samples and a set of symbols generated in random order at the receiver go through performance degradation when biased impulsive noise is added to the channel since the cost function composed of information potentials has no variable to deal with biased signal. Aiming at the robustness against biased impulsive noise, we propose, in this paper, a modified information potential, and derived related blind algorithms based on augmented filter structures and a set of random-order symbols. From the simulation results of blind equalization for multipath channels, the blind algorithm based on the proposed information potential produced superior convergence performance in the environments of strong biased impulsive noise.

• Journal of the Korean Society for Library and Information Science
• /
• v.27
• /
• pp.183-214
• /
• 1994

The purpose of this study is to suggest the schemes to enhance information service functions by the utilization of CD-ROM in medical school libraries. The results of the study are summarized as follows : 1. The selection and evaluation of CD-ROM database are necessary steps in the planning of a CD-ROM. Before the CD-ROM is selected, therefore, medical libraries must make a practical evaluation criteria in important order of information services environment, characteristics of hardware/software, service requirements, price and cost, etc. 2. If possible, CD-ROM MEDLINE must be suited for the information services environment. 3. In case of the popular core journals, full-text CD-ROM should be gradually purchased. 4. In order to reduce the time required from search of bibliographic informations to receipt of original articles, CD-NET system and library holding administration program must be built up and developed. And channel of information search and order/receipt of original article should be varied. 5. Search education program for medical librarians and users should be enforced, and librarians must play an important role in CD-ROM retrieval consultant and intermediator.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.58 no.1
• /
• pp.48-55
• /
• 2009

In order to keep safe driving conditions under road networks, there are several formations such as road structure, road surface condition, traffic occupancy and supplement of an accurate information of traffic status ahead To support safe-driving on each road formation, each formation is supplied with various information to help the driver. However, in some cases like rapid status change at local-scale geography, traffic information systems often displays insufficient information because of the lack of information correlation. In order to accurately aware the driver, all road formation must be in sync. It is important to supply accurate information to the driver because this information directly impacts the drivers on the road. This paper discusses the amber information to keep the least safety driving over road formations including tunnels and bridges. This paper also will propose the informations for safe-driving conditions, information linkage on the road and rule-base safety information, as ITS technology, being displayed for all drivers under the worst weather conditions.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.18 no.6
• /
• pp.1542-1550
• /
• 1994

For a class of singularly perturbed uncertain system, an output feedback control law is designed. The controller structure is designed based on the uncertain reduced-order system, and the controller parameters are determined by information on the reduced-order and full-order systems. It has been shown that the reduces-order system with the designed controller possesses a stability property(specifically, a global uniform attractivity). Furthermore, the stability property of this control scheme is robust with respect to singular perturbation ; i.e., the full-order system, subject to the same controller, possesses the global uniform attractivity, provided the singular perturbation parameter $\mu<\mu^{*}$, where a threshold value $\mu^{*}$ can be computed from the information available on the full-order system.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.26 no.6B
• /
• pp.794-801
• /
• 2001

본 논문에서는 rank-order 필터의 구현을 위해 세 가지 신경회로망의 구조를 제시하고 분석하며 용도를 제안한다. 첫 번째 신경회로망을 이용하여 2-입력 정렬기를 제안하고 이를 이용하여 계층적인 N-입력 정렬기를 구성한다. 두 번째로 입력 신호간의 상대적인 크기 정보를 이용하여 학습 패턴을 구성한 후 역전파 학습 기법을 이용하여 구현되는 순방향 신경회로망을 이용한 rank-order 필터를 구현한다. 세 번째로 신경회로망의 구조의 출력층에 외부 입력으로 순위 정보를 가지도록 하는 rank-order 필터를 순방향 신경회로망을 이용하여 구현한다. 그리고 이러한 제안된 기술들에 대해 확장성, 구조의 복잡도와 시간 지연 등에서의 성능을 비교, 평가한다. 2-입력 정렬기를 이용하는 방식은 확장이 용이하고 비교적 구조가 간단하나 입력 신호들의 정렬을 위해 신경회로망은 순환하는 구조를 가지며 입력 신호의 수에 비례하는 반복 연산 후에 결과를 얻게 된다. 반면에, 순방향 신경회로망을 이용한 rank-order 필터의 구현 방식은 이러한 반복 연산으로 인한 시간 지연을 줄일 수 있으나 상대적으로 복잡한 구조를 가진다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.21 no.2
• /
• pp.357-364
• /
• 1996

This paper presents a new blind identification method of nonminimum phase FIR systems without employing higher-order statistics. It is based on the observation that the absolute mean of a second-order white sequence can measure the higher-order whiteness of the sequence. The proposed method may be a new alternative way to the higher-order statistics approaches. Some computer simulations show that the absolute mean is exactly estimated and the proposed method can overcome the disadvantages of the higher-order statistics approaches.

• Journal of Positioning, Navigation, and Timing
• /
• v.4 no.1
• /
• pp.33-41
• /
• 2015

Compact Network Real-Time Kinematic (RTK) is a method that combines compact RTK and network RTK, and it can effectively reduce the time and spatial de-correlation errors. A network RTK user receives multiple correction information generated from reference stations that constitute a network, calculates correction information that is appropriate for one's own position through a proper combination method, and uses the information for the estimation of the position. This combination method is classified depending on the method for modeling the GPS error elements included in correction information, and the user position accuracy is affected by the accuracy of this modeling. Among the GPS error elements included in correction information, tropospheric delay is generally eliminated using a tropospheric model, and a combination method is then applied. In the case of a tropospheric model, the estimation accuracy varies depending on the meteorological condition, and thus eliminating the tropospheric delay of correction information using a tropospheric model is limited to a certain extent. In this study, correction information modeling accuracy performances were compared focusing on the Low-Order Surface Model (LSM), which models the GPS error elements included in correction information using a low-order surface, and a modified LSM method that considers tropospheric delay characteristics depending on altitude. Both of the two methods model GPS error elements in relation to altitude, but the second method reflects the characteristics of actual tropospheric delay depending on altitude. In this study, the final residual errors of user measurements were compared and analyzed using the correction information generated by the various methods mentioned above. For the performance comparison and analysis, various GPS actual measurement data were collected. The results indicated that the modified LSM method that considers actual tropospheric characteristics showed improved performance in terms of user measurement residual error and position domain residual error.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.21 no.2
• /
• pp.88-96
• /
• 2013

The objective of this research was to evaluate the suitability of sigmoidal and firstorder kinetic equations for simulating the methane production from solid wastes. The sigmoidal kinetic equations used were modified Gompertz and Logistic equations. Statistical criteria used to evaluate equation performance were analysis of goodness-of-fit (Residual sum of squares, Root mean squared error and Akaike's Information Criterion). Akaike's Information Criterion (AIC) was employed to compare goodness-of-fit of equations with same and different numbers of parameters. RSS and RMSE were decreased for first-order kinetic equation with lag-phase time, compared to the first-order kinetic equation without lag-phase time. However, first-order kinetic equations had relatively higher AIC than the sigmoidal kinetic equations. It seemed that the sigmoidal kinetic equations had better goodness-of-fit than the first-order kinetic equations in order to simulate the methane production.