• 대한간호학회지
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• 제32권3호
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• pp.344-354
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• 2002

This study is a fact-finding research to understand the status of visiting nursing services operated by health centers in Korea and it aims to provide basic information for policy development on operation and management of visiting nursing services in health centers. Method: This study investigates the results of visiting nursing services in 242 health centers from Jan. 10 through Dec. 30, 2000, where 3,106 visiting nurses were employed by the public work program. Result: In 2000, 129,401 new household as service recipients was identified and that was 0.9% of Koreas total households (15,137,000), and 5.8% of low income households (2,242,000). The highest high risk group was dementia patients(aver. 55.2/1,000 person). Average number of households visited by visiting nurse were 4.5 households per day and the first-visited houses per visiting nurse were 1.1 households per day. The re-visiting rate was 71.3%. Total 4,059,130 service items were provided and assessment ranked the highest with 33.7%. The satisfaction level of clients on the nurses was an average of 3.17 points in the scale of 4 and the nursing service was a 2.60 points in a scale of 3. Conclusion: Visiting nursing service should continue to provide comprehensive healthcare services in cost-effective ways while cooperating with others

• Earthquakes and Structures
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• 제12권6호
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• pp.699-712
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• 2017

This study evaluates the effectiveness of a newly developed retrofitting scheme for masonry-infilled non-ductile RC frames experimentally and by numerical simulation. The technique focuses on modifying the load path and yield mechanism of the infilled frame to enhance the ductility. A vertical gap between the column and the infill panel was strategically introduced so that no shear force is directly transferred to the column. Steel brackets and small vertical steel members were then provided to transfer the interactive forces between the RC frame and the masonry panel. Wire meshes and high-strength mortar were provided in areas with high stress concentration and in the panel to further reduce damage. Cyclic load tests on a large-scale specimen of a single-bay, single-story, masonry-infilled RC frame were carried out. Based on those tests, the retrofitting scheme provided significant improvement, especially in terms of ductility enhancement. All retrofitted specimens clearly exhibited much better performances than those stipulated in building standards for masonry-infilled structures. A macro-scale computer model based on a diagonal-strut concept was also developed for predicting the global behavior of the retrofitted masonry-infilled frames. This proposed model was effectively used to evaluate the global responses of the test specimens with acceptable accuracy, especially in terms of strength, stiffness and damage condition.

• Asian-Australasian Journal of Animal Sciences
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• 제13권5호
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• pp.575-579
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• 2000

First lactation records of 683 Murrah buffaloes maintained at NDRI, Karnal which were progeny of 84 sires used for comparing the heritability estimates of age at first calving, first lactation milk yield and first service period under single and multiple trait models using restricted maximum likelihood (REML) method of estimation under an individual animal model. The results indicated that the heritability estimates may vary under single and multiple trait models depending upon the magnitude of genetic and environmental correlation among the traits being considered. Therefore, a single or multiple trait model is recommended for estimation of variance components depending upon the goal of breeding programme. However, there may not be any advantage of considering a trait with zero or near zero heritability and having no or very low genetic correlation with other traits in the model. Lower heritability estimates of part lactation yield (120-day milk yield) implied that there may not be any advantage of considering this trait in place of actual 305-day milk yield, whereas, comparable heritability estimates of predicted 305-day milk yield suggested that it could be used for sire evaluation to reduce the cost of milk recording under field conditions.

• 한국전기전자재료학회논문지
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• 제29권5호
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• pp.284-288
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• 2016

Among the various physiological information that could be obtained from human body, heartbeat rate is a commonly used vital sign in the clinical milieu. Photoplethysography (PPG) sensor is incorporated into many wearable healthcare devices because of its advantages such as simplicity of hardware structure and low-cost. However, healthcare device employing PPG sensor has been issued in susceptibility of light and motion artifact. In this paper, to develop the real-time heart rate measurement device that is less sensitive to the external noises, we have fabricated an ultra-small wireless LC resonant pressure sensor by MEMS process. After performance evaluation in linearity and repeatability of the MEMS pressure sensor, heartbeat waveform and rate on radial artery were obtained by using resonant frequency-pressure conversion method. The measured data using the proposed heartbeat rate measurement system was validated by comparing it with the data of an commercialized heart rate measurement device. Result of the proposed device was agreed well to that of the commercialized device. The obtained real time heartbeat wave and rate were displayed on personal mobile system by bluetooth communication.

• Journal of Power Electronics
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• 제17권5호
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• pp.1244-1255
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• 2017

The space vector pulse width modulation (SVPWM) technique is a popular PWM method for medium voltage drive applications. Conventional SVPWM (CSVPWM) and bus clamped SVPWM (BCSVPWM) are the most common SVPWM techniques. This paper evaluates the performance of various advanced BCSVPWM strategies in terms of their harmonic distortion and switching loss based on a uniform frame work. A uniform frame work, pulse number captures the performance parameter variations of different SVPWM strategies for various number of samples with heterogeneous pulse numbers. This work compares different advanced BCSVPWM techniques based on the modulation index and location of the clamping position (zero vector changing angle ) of a phase in a line cycle. The frame work provides a fixed fundamental frequency of 50Hz. The different BCSVPWM switching strategies are implemented and compared experimentally on a 415V, 2.2kW, 50Hz, 3-phase induction motor drive which is fed from an IGBT based 2 KVA voltage source inverter (VSI) with a DC bus voltage of 400 V. A low cost PIC microcontroller (PIC18F452) is used as the controller platform.

• 한국통신학회논문지
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• 제28권5B호
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• pp.466-474
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• 2003

본 논문에서는 최근 효율적이고 경제적인 초고속 광가입자망 기술로서 부각된 Ethernet-PON 시스템을 위한 시뮬레이션 모델을 OPNET을 이용하여 구현한다. 설계한 Ethernet-PON 시스템은 IEEE 802.3ah EFM을 기반으로 요청/허가 TDMA MAC 프로토콜을 사용하며 제어 패킷들의 교환을 통해 등록, 레인징, 동적 대역 할당 등의 기능을 수행한다. 시뮬레이션 모델을 사용하여 초기 등록 절차에서의 성공률과 나중 등록을 위한 지연에 관한 결과를 분석하였다. 또한 사용자의 요구 대역 정보를 기반으로 대역을 동적으로 할당하는 Dynamic TDMA 프로토콜과 사용자의 요구에 관계없이 동등한 대역을 할당하는 Static TDMA 프로토콜의 성능을 채널 이용률 및 큐잉 지연 관점에서 비교하였다. 본 논문에서 구현한 시뮬레이터는 Ethernet-PON 시스템의 설계 과정에서 논의될 수 있는 여러 기술 사항들에 대한 적절한 선택 기준을 모의 실험을 통해 제시할 수 있을 것으로 기대된다.

• 전기학회논문지P
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• 제67권1호
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• pp.21-26
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• 2018

Due to the international environmental regulations and changes in policies, the demand for generators using the renewable energy is increasing. However, renewable energy generators with intermittent output characteristics such as solar and wind power generators, need the buffer facilities such as ESS during system operations. However, because of low price competitiveness in energy storage system, it is difficult to operate the renewable energy generator with ESS. Therefore, the government has recently proposed a policy to compensate the REC for renewable energy system with ESS. For all this, since the initial cost of the ESS is high, it is the most important to calculate and operate the optimal capacity of the ESS through an economic analysis. In this paper, we proposed the method of calculation the optimal capacity of ESS and analyzed economic feasibility of renewable energy system using the ESS according to depreciation in ESS price.

• Smart Structures and Systems
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• 제6권7호
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• pp.851-866
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• 2010

This paper presents a new concept of using PZT (lead zircornate titanate) transducers as a non-destructive testing (NDT) tool for evaluating quality of concrete. Detection of defects in concrete is very important in order to check the integrity of concrete structures. The electro-mechanical impedance (EMI) response of PZT transducers bonded onto a concrete specimen can be used for evaluating local condition of the specimen. Measurements are carried out by electrically exciting the bonded PZT transducers at high frequency range and taking response measurements of the transducers. In this study, the compression test results showed that concrete specimens without sufficient compaction are likely to fall below the desired strength. In addition, the strength of concrete was greatly reduced as the voids in concrete were increased. It was found that the root mean square deviation (RMSD) values yielded between the EMI signatures for concrete specimens in dry and saturated states showed good agreement with the specimens' compressive strength and permeable voids. A quality metric was introduced for predicting the quality of concrete based on the dry-saturated state of concrete specimens. The simplicity of the method and the current development towards low cost and portable impedance measuring system, offer an advantage over other NDE methods for evaluating concrete quality.

• Journal of Electrical Engineering and Technology
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• 제9권5호
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• pp.1501-1510
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• 2014

Low voltage direct current (LVDC) distribution system is a suitable techno-economic candidate which can create an innovative solution for distribution network development with respect to rural electrification. This research focuses on the use of LVDC distribution system to replace some of KEPCO's existing traditional medium voltage alternating current (MVAC) distribution network for rural electrification in South Korea. Considering the technical and economic risks and benefits involved in such project, a comparative techno-economic analysis on the LVDC and the MVAC distribution networks is conducted using economic assessment method such as the net present value (NPV) on a discounted cash flow (DCF) basis as well as the sensitivity analysis technique. Each would play a role in an economic performance indicator and a measure of uncertainty and risk involved in the project. In this work, a simulation model and a computational tool are concurrently developed and employed to aid the techno-economic analysis, evaluation, and estimation of the various systems efficiency and/or performance.

• 한국운동역학회지
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• 제26권4호
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• pp.391-396
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• 2016

Objective: This study aimed to evaluate and identify variables for the standing balance of elderly subjects with different balancing abilities by using Kinect and Wii Balance Board. Method: The Berg Balance Scale (BBS) test was performed in 40 elderly subjects aged ${\geq}65years$ who can perform daily activities. The participants were divided into two groups, the healthy seniors (n = 20, BBS score ${\geq}52$) and the seniors with balancing problems (n = 20, BBS score < 52). Each group performed two standing tests (eyes open and eyes close) with two devices (Kinect and Wii Balance Board). The root mean square (RMS), mean distance (MDIST), range of distance (ROD), mean velocity, and 95% ellipse area were calculated from the measured data. Results: Among the calculated variables, RMS, MDIST, and ROD in the mediolateral direction showed significant differences between the two groups and a negative correlation with BBS scores. Conclusion: The results of the present study show that simple standing balance of the elderly can be measured with Kinect and Wii Balance Board, which are low-cost, easy to carry, and easy to use, by using the selected variables.