• Journal of the Korean Society for Marine Environment & Energy
• /
• v.18 no.4
• /
• pp.291-297
• /
• 2015

The wave spectrum was generated from wave data measured at the Chagwi-do site in Jeju, where a 10MW class floating wave-offshore wind hybrid power generation system will be installed. The latching control technology (Sheng et al.[2015]) was applied in order to improve the extracted power from WEC (Wave Energy Converter), which is heaving in corresponding irregular waves. The peak period as a representative value of irregular waves was used when we determined the latching duration. From the numerical results in the time-domain analysis, the latching control technology can significantly improve the extracted power about 50%.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1995.04a
• /
• pp.813-821
• /
• 1995

본 연구의 목적은 심리육체적 방법(Psychophysical method)을 이용하여 다양한 중량물운반 유형에서의 최대허용하중을 구하는 것이며 이의 타당성을 생리학적 방법(physiological method)을 이용하여 검토하는 것이다. 또한, 인체측정과 근력측정 자료를 이용하여 각 운반유형에서의 최대허용 하중을 예측하는 모형을 개발하고자 한다. 본 연구에서는 네 가지의 운반유형(Front carrying, One-hand side carrying, Two-hands side carrying 그리고 Back carrying)과 두가지의 보행 속도 (50.0 그리고 79.2 m/min)를 주요변수로 8가지의 작업에 대해 무작위로 선택하여 각 작업에 대한 최대허용 하중을 시간과 경비의 감소측면에서 폭넓게 사용되고 있는 심리육체적 방법으로 구하였다. 피실험자는 운반작업의 경력이 있는 실제 작업자군(n=7)과 그렇지 않은 학생군(n=10)으로 구분하여 건강한 남성 피실험자를 대상으로 연구를 실시하였다. 주실험전에 인체측정과 근력측정을 실시하였다. 이후에 심리육체적 방법과 생리학적 방법을 실시간(on-line)으로 실시하였다. 연구결과로 학생군과 작업자군간의 신체조건은 뚜렷한 차이를 보이지 않았으나 근력은 작업자가 우월하였다. 심리육체적 방법을 사용하여 도출된 최대허용 하중은 학생군, 작업자군 모두 운반유형의 변화에 따라 유의함을 보였다.(학생군:p=.0001 작업자군:p=.0001). 반면에 속도의 변화는 유의하지 않았다(학생군:p=.7954 작업자군:p=.9231). 또한 학생군과 작업자군 모두 Back carrying에서 가증 큰 하중을 운반하였다(학생군:8.16kg 작업자군:12.9kg). 심박수를 이용한 생리학적 연구에서는 평균 심박수가 거의 100 이하를 유지하므로써 피실험자들이 8시간 작업기준으로 보아 무리가 없는 최대허용 하중을 결정하였음을 보였다. 또한 각 운반작업에 대한 최대허용 하중을 예측하는 회귀모형을 제시하였다.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.37 no.4
• /
• pp.65-71
• /
• 2000

Finite wordlength effect of the recursive implementation of SDFT(sliding-DFT) is analytically derived in this paper. Representation errors of the twiddle coefficients and the data registers are the two major causes of the spectral errors in the recursive implementation. The noise-to-signal ratio is analytically derived in terms of the coefficients wordlength, the data registers wordlength, and the DFT's block-length used in the computation Error dynamic equation is obtained from the recursive DFT and the probabilistic models for the coefficients error and the round-off error are introduced for the NSR derivation, The result of the NSR derivation is verified with the simulation data.

• Geophysics and Geophysical Exploration
• /
• v.18 no.3
• /
• pp.133-142
• /
• 2015

Displacement of the Earth's surface due to atmospheric loading has been recognized since a century years ago, and its accurate estimation is required in present day geodesy and surveying, particularly in space geodesy. Atmospheric load deformation in continental region can readily be calculated with the given atmospheric pressure field and the load Green's function, and, in near coastal area, approximate model is used for the calculation. The changes in the Earth's atmospheric circulation and the seasonal variation of atmospheric pressure on two hemispheres of the Earth are the each main causes of variation of the Earth's spin angular velocity and polar motion respectively. Wind and atmospheric pressure do the major role in other periodic and non-periodic perturbations of the positions in the Earth's reference frame and variations in the Earth's spin rotational state. In this reviewing study, the developments of related theories and models are summarized along with brief description of phenomena, and the geodetic perturbing effects of a hypothetical typhoon passing Korea are shown as an example. Finally related existing problems and further necessary studies are discussed in general.

• Korean Journal of Clinical Pharmacy
• /
• v.19 no.2
• /
• pp.81-88
• /
• 2009

Objectives: With more and more health economic evaluations being performed in many countries, the question of whether the results from the foreign studies can be transferred to other country is becoming important. The objective of this study was to conduct a case study using three transferability diagnosis tools for economic evaluation on rheumatoid arthritis. Methods: Three diagnosis tools were used to assess transferability: Welte's tool, Boulenger's and Urdahl's. Five researchers who have experience on economic evaluation made consensus on the evaluation through the semi-delphi method. Results: With Welte's tool, absolute and relative prices in healthcare, practice variation, health-status preference, productivity and work-loss time were evaluated as biased. The transferability information score by Boulenger's was 85.9%, which means qood quality reporting. In case of Urdahl's, research questions were well defined and reporting was transparent and explicitly stated. However, both the relevance of data inputs to Korea and robustness of model were relatively low. In conclusion the UK study on rheumatoid arthritis could be partially transferable to Korea, and will need modeling-based adjustments.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• v.29 no.1
• /
• pp.153-161
• /
• 2005

Recently, The government of Korea declared to develop RFID(Radio Frequency IDentification) as one of key strategic technology to perform U-Government using Ubiquitous technology. But, most of the related technologies for RFID are mainly focused on the inlaned application excepting marine applications. The last target of this study is to implement new Marine RFID(M-RFID) that can cover all of EEZ areas as large five times as inland volume. In this paper, as a basic study for the M-RFID, we carried out an establishing the concept design of M-RFID, developing the construction method of M-RFID and, extending the idea of M-RFID. As studying results, it is known that the M-RFID can be use in many practical areas such as the protection of EEZ area and aqua culture, the safety of fisher man, the disaster control for inlander and, fisheries ligistics with real-time.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.5 no.5
• /
• pp.419-426
• /
• 2000

Generally diode rectifier has been used as Preregulator of arc- welding machine. Its defect is the generation of high current harmonics which result In utility pollution. In this parer, using the three-phase PWM converter, the input performance of arc-welding machine is improved by increasing the input power factor. When the diode rectifier in the arc-welding machine is replaced with three-phase PWM converter, PWM converter should control DC voltage of the output side. If PI controller is used for the output DC voltage regulator, the output DC voltage has high ripple voltage due to the instantaneous load variation in the arc-welding machine. In this paper, the feedforward compensator has been introduced to reduce the DC voltage ripple. It lessens the influence of load current which is the disturbance of the output DC voltage regulator. Theoretical prediction of this analysis has been verified by comparing with experimental data

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.26 no.1
• /
• pp.29-37
• /
• 1989

This paper presents an application of the extended DP matching method to the on-line recognition of cursive Hangeul (Korean characters). We decrease the number of matching's objects by performing rough classification matching which makes the best use of features in the first and the last segment of Hangeul. By adding the extraction function of the basic character patterns to DP matching method, we try to calculate precisely the difference among Hangeul. The extraction of the basic character patterns is done by examining the features of segments in character. Applying the extended DP matching method to the on-line recognition of cursive Hangeul, absorption of writing motion and stable separation of strokes can be performed with flexibility.

• Journal of Mushroom
• /
• v.9 no.1
• /
• pp.39-43
• /
• 2011

Soybean curd was mixed with mushroom powder to develop new healthful foods, and changes in quality characteristics were investigated. The yields of the soybean curds containing 3~12% powder of Pleurotus ostreatus(PPo), 3, 6% of powder of Pleurotus cornucopiae(PPc), Pleurotus salmoneostramineus(PPs), Agrocybe aegerita(PAa) were higher than those of the control. The hardness level was highest in the 3% of dried mushroom power, The addition of mushroom powder to curd evidenced a significantly lower L value(lightness) than was detected in the control. In particular, PPs added soybean curd observed the highest a value(redness). In terms of overall acceptability, the preferred soybean curd samples were the 6% PPo, 3% of PPc, PPs and, PAa.

• Korean Journal of Agricultural Science
• /
• v.40 no.4
• /
• pp.377-383
• /
• 2013

Premature-green rice is typically obtained by early harvest when culms of rice still appear green in color, and the rice and its food products have been considered as wellbeing foods. This study was carried out to determine the quality characteristics of cookies made from flour added with 10, 20, and 30% whole green rice powde r(WGRP) of two kinds of Hopum and Shinsun waxy rice. The quality characteristics of cookies, including pH, spread factor, color, hardness, and sensory properties, were estimated. WGRP with different levels of 10, 20, and 30% was added into powder for preparing cookies, and their quality properties were evaluated. The pH and hardness of the cookies increased, while spread factor showed highest added with 20% Hopum and Shinsun waxy rice. The color (L) of cookies decreased 20% added with Hopum and Shinsun waxy rice. The sensory properties of cookies was highest added with 20% Hopum and 10% Shinsun waxy rice. The result of this study suggest that addition of 20% Hopum and 10% Shinsun waxy rice are available rice cookies. It was concluded that WGRP may have a potential in bakery industry as a new food material.