• 한국지능시스템학회논문지
• /
• 제24권5호
• /
• pp.462-469
• /
• 2014

본 논문은 공감각의 공학적인 응용 및 표현방법에 관한 기초연구로서, 인간이 인지할 수 있는 감각들 중 근감각을 시각 및 청각 요소로 변환하는 기본 시스템의 구축을 목표로 한다. 구축방법으로서, 근감각 신호를 3축 가속도 센서 및 2축 자이로센서로부터 계산된 롤(roll), 피치(pitch) 신호를 통하여 근감각 신호 데이터를 획득하고 그 데이터에서 시각적 컬러 정보와 청각적 정보로 변환하는 방법을 제안한다. 롤 신호는 HSI 컬러 모델의 명도(Intensity)와 청각의 요소인 옥타브(Octave)로 변환하고, 피치 신호는 HSI 컬러 모델의 색상(Hue)과 청각의 음계(Scale)에 대응하여 변환한다. 추출된 HSI 컬러모델의 요소성분들을 기반으로 RGB 컬러모델로 변환한 후 실시간 컬러 출력신호를 얻는다. 또한, 청각의 요소인 옥타브 및 음계 성분을 기반으로 MIDI 신호로 변환, 합성한 후 실시간 사운드 출력신호를 얻는다. 실험에서, 신체의 움직임 즉 근감각을 표현하는 롤과 피치 값에서 색과 음 사이의 유사성에 기초한 변환관계에 따라 정상적인 색과 음이 출력되는 것을 확인하였다.

• 한국정밀공학회지
• /
• 제15권4호
• /
• pp.134-140
• /
• 1998

The authors have shown that the performance of discrete-time observer-based monitoring systems can be represented by the performance index k$_2$(P) (condition number of the eigensystem P of the observer matrix in terms of L$_2$ norm). The observers with the minimized performance index can be defined as robust observers in the sense that the observer performance can be guaranteed in harsh environments. In this paper, based on the performance index, a design methodology for the robust discrete-time observer is developed. Similar to the continuous-time case, the methodology determines the structure and eigenvalues of the observer matrix simultaneously. A complete design procedure is given for single-output case and is illustrated with a spindle-driver example. The simulation results demonstrate the improved performance compared with a traditional pole-placement observer technique.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
• /
• pp.694-697
• /
• 2003

In applying LCD to TV application, one of the most significant factors to be improved is image sticking on the moving picture. LCD is different from CRT in the sense that it's continuous passive device, which holds images in entire frame period, while impulse type device generate image in very short time. To reduce image sticking problem related to hold type display mode, we made an experiment to drive LCD like CRT. We made articulate images by turn on-off backlight, and we realized the ratio of Back Light on-off time by adjusting between on time and off time for video signal input during 1 frame (16.7ms). Conventional CCFL (cold cathode fluorescent lamp) cannot follow fast on-off speed, so we evaluated new fluorescent substances of light source to improve residual light characteristic of CCFL. We realized articulate image generation similar to CRT by blinking drive. As a result, reduced image sticking phenomenon was validated by naked eye and response time measurement.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 하계학술대회 논문집 B
• /
• pp.1169-1171
• /
• 2004

Voltage source inverters are required dead time to prevent the short current in the dc link. In recent years, the dead time effect has been investigated in many literatures. This paper presents on the novel space vector PWM inverter without dead time. The proposed inverter don't need to sense load current and to calculate for dead time compensation. Transformers are inserted each leg in the proposed inverter. The proposed method is analyzed each mode and then the simulation results verify the proposed method.

• 한국경영과학회지
• /
• 제28권2호
• /
• pp.75-89
• /
• 2003

Media Access Control (MAC) Protocol in IEEE 802.11 Wireless LAN standard supports two types of services, synchronous and asynchronous. Synchronous real-time traffic is served by Point Coordination Function (PCF) that implements polling access method. Asynchronous nonreal-time traffic is provided by Distributed Coordination Function (DCF) based on Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol. Since real-time traffic is sensitive to delay, and nonreal-time traffic to error and throughput, proper traffic scheduling algorithm needs to be designed. But it is known that the standard IEEE 802.11 scheme is insufficient to serve real-time traffic. In this paper, real-time traffic scheduling and admission control algorithm is proposed. To satisfy the deadline violation probability of the real time traffic the downlink traffic is scheduled before the uplink by Earliest Due Date (EDD) rule. Admission of real-time connection is controlled to satisfy the minimum throughput of nonreal-time traffic which is estimated by exponential smoothing. Simulation is performed to have proper system capacity that satisfies the Quality of Service (QoS) requirement. Tradeoff between real-time and nonreal-time stations is demonstrated. The admission control and the EDD with downlink-first scheduling are illustrated to be effective for the real-time traffic in the wireless LAN.

• 한국경영과학회:학술대회논문집
• /
• 한국경영과학회 1996년도 추계학술대회발표논문집; 고려대학교, 서울; 26 Oct. 1996
• /
• pp.307-309
• /
• 1996

This paper analyses a deterministic scheduling problem concerned with manufacturing two types of components at a pre-assembly stage which consists of two independent feeding machines each producing its own type of component. Each type represents a unique component which may have variations in its size or quality. Therefore, the completion time of each component depends on both its type and quality (size) variations. Such manufactured components are subsequently assembled into various component dependent products. The problem has the objective measure of minimizing the total weighted completion time of a finite number of jobs(products) where the completion time of each job is measured by the latest completion time of its two components at the pre-assembly stage. The problem is shown to be NP-complete in the strong sense. A WSPT rule coupled with a machine-aggregation idea is developed for good heuristics which show the error bound of 2.

• 대한가정학회지
• /
• 제33권4호
• /
• pp.301-313
• /
• 1995

The purpose of this study was to investigate the differences of child care and it's costs between the full time housewives and employed wives' families with preschool children. the results of this study were as follows ; 1) The child care was performed primarily by herselves in the case of full time housewives' families, whereas the child care of employed wife families was done by babysitter or nursing facilities. 2) Most of unemployed wives' families undertook the burden of time cost, whereas the families of employed wives had to pay heavy expenses of money cost f9or the child care arrangements 3) In the estimation of money cost for the child care arrangements income had the highest effect. In contrast with this, in the case of time cost, occupational status of housewives had the highest effect. It was suggested for enhancing the sense of well - being of housewife it is necessary to perceive the value of household production and the social support for child care arrangements in all families, whether unemployed or employed.

• 한국식물학회:학술대회논문집
• /
• 한국식물학회 1996년도 제10회 식물생명공학심포지움 고등식물 발생생물학의 최근 진보
• /
• pp.4-9
• /
• 1996

The majority of plants sense environmental signals, such as day length or temperature, to select their transition timing from vegetative growth t flowering. Here, we report the identification of a regulatory gene, OsMADS1, that controls the photoperiod sensitivity of flowering time. Constitutive expression of OsMADS1 in a long-day flowering plant, Nicotiana sylvestris, resulted in flowering in both short-day long-day conditions. Similarly, ectopic expression of the gene in a short-day flowering plant, N. tabacum cv. Maryland Mammoth, also induced flowering regardless of the day length. The transition time was dependent on the level of the OsMADS1 transcript in transgenic plants. These suggest that OsMADS1 is a key regulatory factor that determines the transition from shoot apex to floral meristem and that it can be used for controlling flowering time in a variety of plant species.

• Journal of Welding and Joining
• /
• 제18권1호
• /
• pp.97-103
• /
• 2000

Time series analysis results show the SVD is a candidate of on-line monitoring of welding penetration when the covariance matrix of a full penetration is used as a mapping function. As the reconstructed embedding vectors from the chaotic scalar time series are manipulated by the covariance matrix, the mapped tim series lie on a hyper-ellipsoid which the lengths of semi-axes are the squared eigenvalues of the covariance matrix in the case of full penetration. These visualize by two dimensional stroboscope views. The other cases like partial penetration, are different in the sense of sizes and shapes. Here we test two types of time series; the ion current and the X-ray. The ion current is better than the X-ray as an on-line monitoring signal, because the difference of the eigenvalue spectrum of the ion(between the pull penetration and partial penetration) is bigger than those of the X-ray.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2002년도 춘계학술대회 논문집
• /
• pp.259-262
• /
• 2002

This paper provides the experimental verification of a non-destructive time domain approach to examine structural damage. Time histories of the vibration response of structure were used to identify the presence of damage. Damage in a structure cause changes in the physical coefficients of mass density, elastic modulus and damping coefficient. This paper examines the use of beam like structures with PVDF sensor and PZT actuator to perform identification of those physical parameters, and hence to detect the damage. Experimental results are presented from tests on cantilevered composite beams damaged at different location and with damage of different dimensions. It is demonstrated that the method can sense the presence of damage, and characterize the damage to a satisfactory precision.