• Journal of Korean Society of Coastal and Ocean Engineers
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• v.11 no.1
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• pp.56-67
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• 1999

It is desired to use a domestically manufactured ocean data buoy for the long-term operational ocean monitoring. The ocean data buoy manufacturing technology was introduced through the research cooperation with the Qingkong University of Taiwan. The introduced ocean data buoy system was further expanded and improved for more efficient application for the marine environmental monitoring in Korea. The size of the ocean data buoy is 2.5 m in diameter, which is smaller compared to the NOAA's 3.0 m discus buoy to allow easy land transportation and ocean deployment as well. From the dynamic response test of the buoy carried out numerically, it was shown that the measurement of waves with period greater than 4 seconds is acceptable. The measurement and control system of the data buoy were improved to increase the number of measuring parameters, to reduce power consumption and to enhance better data analysis and management. Each component of the improved data buoy system was described in detail in this paper. Water quality sensors of water temperature, salinity, DO, pH and turbidity were added to the system in addition to the marine meteorological sensors of wind speed and direction, air temperature, humidity, air pressure and wave. Inmarsat satellite communication system is used for the real-time data telemetry from the buoy deployed offshore. A field performance test of the improved and domestically manufactured buoy was carried out for a month at the open sea off Pohang together with DatawelI's Wave-rider buoy to compare the wave data. The results of the test were satisfactory.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.6
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• pp.374-386
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• 2010

Recently, the theoretical and experimental research is being made actively in control character of waves of perforated-wall caisson breakwater like the slit caisson. This study showed that the character of reflection coefficient and the wave pressure acting on the front and inner of slit caisson were estimated in two and three dimensional numerical wave flume and compared each other. The numerical experiment was set and conducted by various cases as to a variety of wave steepness under 7 sec, 9 sec, 11sec and 13 sec period condition. In this study using a 2 and 3 dimensional numerical wave flume, it applied the Model for the immiscible two-phase flow based on the Naveir-Stokes Equations. This technique can easily reproduce a complicated physical phenomenon more than others and organize the program simply. According to the results of the experiment, the reflection coefficient was estimated high in short-period waves. However, 2-dimensional numerical experiment and 3-dimensional numerical experiment were the same in case of the long-period waves and high wave steepness. And to conclude in case of short-period waves the pressures were a relatively small difference between the two, but there was a big gap in longperiod waves and high wave steepness.

• Archives of design research
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• v.12 no.2
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• pp.133-144
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• 1999

Considering product as mass of information, it is very critical for designers to have good means of accessing to and organizing information on products. However, designers conventionally depend on their experience, bunch of catalogues, or short visit to some fairs for gathering information on products. There are no systematically organized information for designing new products. If any, those are ones developed by market researchers or engineers who speak fundamentally different language from designers. It is needed to develop the information system through which designer can get insights on the essence of product and communicate information with various persons involved in new product planning. At first, the design information in product planning is discussed and the necessity of development of new design information system is emphasized. Then, product is understood as a composite of various attributes and a set of fundamental attributes of product is defined by surveying and summarizing existing theories of product attributes: namely technological, human, and market attributes. The possibility of new design information system is explored by analyzing various relationships between attributes of different products. Computer program 'DISPP' displays various visual information of product itself, perceptual map, trend slope, profile chart and general information of manufacturer, style, color, price, size. Finally, findings of thesis are concluded and further prospects of the study are proposed.

• Journal of the Society of Disaster Information
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• v.15 no.4
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• pp.524-530
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• 2019

Purpose: In this paper, we construct a detailed three-dimensional interface element using a three-dimensional analysis program, and evaluate the composite behavior stability of the connector by applying physical properties such as the characteristics of general members and those of reinforced members Method: The analytical model uses solid elements, including non-linear material behavior, to complete the modeling of beam structures, circular flanges, bolting systems, etc. to the same dimensions as the design drawing, with each member assembled into one composite behavior linkage. In order to more effectively control the uniformity and mesh generation of other element type contact surfaces, the partitioning was performed. Modeled with 50 carbon steel materials. Results: It shows the displacement, deformation, and stress state of each load stage by the contact adjoining part, load loading part, fixed end part, and vulnerable anticipated part by member, and after displacement, deformation, The effect of the stress distribution was verified and the validity of the design was verified. Conclusion: Therefore, if the design support of the micro pile is determined based on this result, it is possible to identify the Vulnerable Parts of the composite behavior connector and the degree of reinforcement.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.8A
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• pp.739-752
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• 2002

Recently, to utilize the limited bandwidth effectively, the concept of partial response (PR) signaling has widely been adopted in both the high-speed data transmission and high-density digital recording/playback systems such as digital microwave, digital subscriber loops, hard disk drives, digital VCR's and digital versatile recordable disks and so on. This paper is concerned with adaptive equalization of partial response channels particularly for the magnetic recording channels. Specifically we study how the PR channel equalizers work for different choices of desired or reference signals used for adjusting the equalizer weights. In doing so, we consider three different configurations that are actually implemented in the commercial products mentioned above. First of all, we show how to compute the theoretical values of the optimum Wiener solutions derived by minimizing the mean-squared error (MSE) at the equalizer output. Noting that this equalizer MSE measure cannot be used to fairly compare the three configurations, we propose to use the data MSE that is computer just before the final detector for the underlying PR system. We also express the data MSE in terms of the channel impulse response values, source data power and additive noise power, thereby making it possible to compare the performance of the configurations under study. The results of extensive computer simulation indicate that our theoretical derivation is correct with high precision. Comparing the three configurations, it also turns out that one of the three configurations needs to be further improved in performance although it has an apparent advantage over the others in terms of memory size when implemented using RAM's for the decision feedback part.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.908-908
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• 2012

국내 기후 특성상 하절기에 집중되는 강우로 인해 댐의 건설을 홍수조절, 용수확보 및 전력생산 등의 목적에 있어서 불가피하다. 이와 같은 저수지와 하류하천은 댐 수문 개폐에 따라 흐름변화로 인하여 수체의 거동 및 수질 변화가 발생하며, 일반적인 하천과는 다른 특성을 지니게 된다. 또한 수심이 깊은 저수지의 경우에는 흐름방향과 더불어 수심 방향의 특성도 중요하며, 수리 및 수질 모형의 연계를 통한 3차원적인 해석을 필요로 한다. 유역 내 지상 또는 대기에서 발생한 모든 오염물질은 강우에 의해 하천과 호수와 같은 수체로 유입되며, 강우가 발생했을 때 유역의 토지피복 상태와 수리, 지형, 강우강도, 토양의 특성에 의해 하천으로 유입되는 오염물질의 농도와 부하특성이 달라진다. 비점오염물질의 축적이 가능한 호수나 저수지에서는 비점오염원의 유입이 더 큰 문제가 되며, 유량이 극히 미미한 하천의 경우에는 강우초기에 일시에 집중적으로 유입되는 초기 오염 부하량이 문제가 된다. 강우유출수의 하천 유입은 강우 현상과 밀접한 관계를 맺고 있으므로 그 제어가 쉽지 않다. 이러므로 이를 총괄하는 유역통합관리기술이 필요로 하며, 기존의 유역통합관리기술은 댐 상류유역을 중심으로 개발되고 있으며, 댐 상류유역과 저수지, 하류하천으로 구분되어 연구되어 왔다. 또한 각각의 모형이 개별적으로 적용되어 통합적인 평가시스템이 표준화되지 않은 관계로 댐 상하류 모니터링 자료가 연계된 실무 적용이 이루어지지 않고 있다. 따라서 하천 수리 수문학적 역학구조를 이해하고 그 특성에 적합하게 평가할 수 있는 표준화된 시스템이 구축되어야 한다. 또한 효과적인 유역통합관리를 위해서는 하천의 현재 뿐만 아니라 장래에 대한 예측부분도 포함되어야 한다. 본 연구에서는 댐 유역에서의 유출과 수질 변화를 모의하고 이를 이용하여 저수지 내에서의 오염물질 거동에 대해서 해석하였다. 또한 기후변화에 따른 유역, 저수지 및 하천에 미치는 영향을 고려하기 위하여 고해상도 지역기후전망 모의자료를 이용하여 수문학적 스케일로 통계적 상세화한 후 지역별 상세수문시나리오를 생산하여 미래 예측에 활용하였다. 기후변화 시나리오의 상세화를 통한 상세지역의 기후를 예측하고, 예측된 기상자료를 이용하여 유역모델을 모의하여 미래의 유출 및 수질 변화를 파악할 수 있는 기술 개발로 인해 저수지의 운영에 도움을 주고, 주수지의 치수증대 사업 등 유출의 변화에 따른 하류하천 변화를 파악할 수 있고, 기후변화에 따른 하류하천에 대한 홍수기 때 치수, 이수 및 방재에 대하여 기초자료를 제공할 수 있을 것으로 판단된다.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.549-555
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• 2010

Here we focused on tip-burn and blossom-end rot (BER) symptoms in the tomato plants expressing the constitutively active form of $Ca^{2+}/H^+$ antiporter (sCAX1) and/or a Ca-binding protein (calreticulin, CRT) genes during their whole growth period. Conclusively we demonstrated that CRT is able to suppress the tip-burn and BER symptoms that were induced by sCAX1. Under poor nutrition condition, tomato plants overexpressing sCAX1 showed severe necrotic collapses in both roots and shoot polar tissues, which are in accordance with $Ca^{2+}$ deficient symptoms frequently observed in an agricultural cultivation of tomato. Reciprocal grafting trials using sCAX1 and wild type plants revealed that the tip-burn symptom by sCAX1 overexpression is not caused by hindrance of $Ca^{2+}$ uptake from soil. We constructed CRT overexpressing transgenic tomatoes, and crossed them with sCAX1 transgenic plants to investigate the effects of CRT on the symptoms of sCAX1 transgenic plants. Co-expression of sCAX1 and CRT significantly suppressed the $Ca^{2+}$ deficient symptoms of sCAX1 transgenic plants. Those results suggest the model that $Ca^{2+}$ homeostasis disturbed by the overexpression of sCAX1 may be suppressed by the co-expression of CRT.

• Korean Journal of Ecology and Environment
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• v.47 no.spc
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• pp.1-9
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• 2014

Lake Suwa is a natural lake which is well-known for sightseeing and fisheries. It had suffered severe eutrophication during 1960s and 1970s with the occurrence of cyanobacterial blooms and the extinction of some benthic animals. Since 1980 water quality has been improved due to efforts of local government, scientists, and citizens. Of various methods that were attempted to improve the water quality of Lake Suwa biological methods received much attention, because it can improve the lake ecosystem integrity and fisheries in addition to the water quality. The aim of this paper is to introduce the biological methods for water quality improvement that had been employed in Lake Suwa, Japan, and their contribution to the economic benefit of local residents. Until now a significant restoration of water quality has been achieved, but there are insufficient recovery of the sediment and biota due to anoxic hypolimnion of the lake. This study proposed suspended cage culture of bivalves as a feasible method of water quality improvement. Increased grazing by bivalves will contribute to the improvement of water quality and fisheries production, which will contribute both to the ecological restoration and economy of local residents.

• Journal of Biomedical Engineering Research
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• v.19 no.2
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• pp.163-170
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• 1998

The ultimate goal of total artificial heart is permanent substitute for a failed heart in a patient without any other therapeutic modality. Until now, infection has been the main problem related to the mechanical circulatory support system. The best way to solve this catastrophic complication and to improve the quality of life of TAH patients in terms of tethering must be implantation of TAH totally. The EH-TAH has been developed in NCVC from 1987 for this purpose. The system consists of an energy converter and pumps, which are designed to be placed in abdomen and pericardial space separately for a good anatomical fit. To evaluate the anatomical fit and hemodynamic performance of the EH-TAH, in vivo test was done. General condition of the animal and hemodynamic status had been stable until the TAH stopped on the 11th pumping day. The estimated cardiac output was about 7.7L/min. The values of mean aortic pressure, left and right atrial pressure were 93$\pm$10, 19$\pm$3 and 15$\pm$4 mmHg, respectively. The correlation coefficient between left and right atrial pressure was 0.96, which represents the dynamic function of the interatrial shunt in controlling left-right imbalance of cardiac output. During pumping days, the temperature on the surface of actuator had been maintained at 39.7$\pm$0.4$^{\circ}C$, less than 1$^{\circ}C$ higher than the rectal temperature. The TAH stopped on the 11th day due to mechanical problems. We concluded that the EH-TAH possessed satisfactory basic performance including anatomic fit and hemodynamic adequacy, although there were several mechanical problems to be solved yet.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4656-4663
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• 2010

In this study, the 3D computational fluid dynamics (CFD) was performed in relation to the internal fluid characteristics, flow distribution, air mean ages, and residence time for the development of the most optimal model in the complex post-disposal device. As it is expected that a channeling (drift) would be made by the semi-dry reactor due to the large difference in the flow distribution by the compartment in the bag filter, a structural improvement should be urgently made for more uniformed flow distribution in the bag filter. In addition, it showed the possibility that the velocity field and distribution characteristics of the residence time could be improved through a modification to inlet structure of the spray dryer reactor. The complex post-disposal device, modified and supplemented with this analysis, integrated the semi-dry reactor and the bag filter in a single body, so it follows that the improvement can make the device compact, the installation area, the operation fee, and management more convenient.