• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.33 no.3
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• pp.173-182
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• 1997

This study is a basic research in purse seine fishery : on the behaviour of fish schools of tilapia Tilapia mossambica in the process of catch of the purse seine fishing method. The experiment was carried out for the mackerel purse seine which using of power block by fishing fleet system in the near sea of Cheju Island and as a forecast in the near future on the purse seine fishing, using of triplex net winch by one boat system in the near sea of Norway. These model purse seines were made of the scale of 1/180 of its full scale. The model purse seine test on the escaping behaviour of fish school by gap, area reducing of gap and tension of purse line was carried out in the stagnant water of experimental water tank. Designing and testing for the model purse seines were based on the Tauti's law. The results obtained were as follows : 1. When the time for the completing of pursing was 20 minutes, average swimming speed of fish school through a gap was 9.71cm/sec for powerblock seine and 9.97cm/sec for triplex seine. 2. In the case of pursing time in actual value was 20minutes, at 50 percent of the pursing, swimming behaviour of fish school in purse seine was 10% to I section, 80% to II section, 10% to III sectional direction for powerblock seine and a similar tendency for triplex seine. 3. In the case of pursing time in actual value was 20 minutes, at the time of 10 minutes have proceeded since then, area reducing rate of gap of the seine in projected front view was 63.5% for powerblock seine and 67.5% for triplex seine. 4. In the case of pursing time in actual value was 20 minutes, escaping rate of fish school by gap in projected front view was 70% for powerblock seine and 30% for triplex seine. Maximum tension of purse line was about 8.1 tons for powerblock seine and about 8.3 tons for triplex seine.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.319-324
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• 2022

The objective of this study was to determine the proper night interruption of photoperiods and dark periods for accumulating bioactive compounds of Agastache rugosa without decreasing plant growth. Five-week-old seedlings were transplanted in a DFT system with white LEDs. A. rugosa was treated with night interruption time treatments of 18:1:2:3, 18:2:2:2, 18:3:2:1 (light:dark:light:dark), and 20:4 (control) for 4 weeks. There were no significant differences except for leaf length, leaf width, and the number of flowers. The content of antioxidants in the shoot of A. rugosa was high in tilianin and acacetin, and the content of rosmarinic acid (RA) was significantly higher in the underground part. The RA content per dry weight of A. rugosa was 47.92 and 51.46% higher than that of the control in 18:1:2:3 and 18:2:2:2, and tilianin and acactin per dry weight were significantly higher in 18:3:2:1. There was no significant difference in growth due to the same day light integral, but 18:2:2:2 showed high total polyphenol contents. Therefore, it is thought that the effect of increasing secondary metabolites of A. rugosa without degradation of growth can be expected through night interruption treatment in plant factory cultivation systems using artificial light.

• Journal of the Korea society of information convergence
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• v.5 no.2
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• pp.77-83
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• 2012

This study was cosmetic contact lens wear for up to 2 weeks in for the evaluation of the insertion. In 1 week during weeks 1 and 2 has been rated 'positive' or 'insert' easy insertion and removal of lenses in the mirror when I saw the 'red eye' negative 'rating in 18 patients (45 %), in 2 shown in 14 patients (35%) as a 'negative' rating over time, depending on the awareness hyperemia has been reduced could see. Future lens purchases from doctors' Week 1 at the 2nd week, came as a result of the positive> negative evaluation was positive = negative. Rating, but usually more than 1 week, 2 weeks, 26 patients (65%) showed no change. State upon insertion of sight, wearing period increased dryness and showed a more positive assessment, the Comfort showed similar ratings. Somewhat negative assessment upon removal of vision status, comfort, dryness, day-to-day life at present, but in both state vision, comfort, dryness positive assessment appears worn than when a positive evaluation appears was unknown.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.5
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• pp.464-473
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• 2001

Since DCT algorithm divides an image into blocks uniformly in both the spatial domain and the frequency domain, it has a weak point that it can not reflect HVS(Human Visual System) efficiently To avoid this problem, we propose a new algorithm, which combines only the merits of DCT and wavelet transform. The proposed algorithm uses the high compaction efficiency of DCT, and applies wavelet transform mode to DCT coefficients, so that the algorithm can utilize interband and intraband correlations of wavelet simultaneously After that, the proposed algorithm quantizes each coefficient based on the characteristic of each coefficient's band. In terms of coding method, the quantized coefficients of important DCT coefficients have symmetrical distribution, the bigger that value Is, the smaller occurrence probability is. Using the characteristic, we propose a new still image coding algorithm of symmetric and bidirectional tree structure with simple algorithm and fast decoding time. Comparing the proposed method with JPEG, the proposed method yields better image quality both objectively and subjectively at the same bit rate.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.6
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• pp.2015-2025
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• 1991

A long and light-weight forearm of the vertical 2 DOF robot manipulator with a heavy payload driven by parallel drive mechanism is modelled as a Euler-Bernoulli beam with a tip mass subjected to a high speed rotation. Governing equation is obtained by Hamilton's principle and represented as state variable form using the perturbed variables which describe the perturbed errors at the manipulator's final configuration. Digitial optimal control and observer theory are used to suppress the forearm vibration and control the positions of the joint angles with measured/estimated state feedback. Computer simulations and experimental results are obtained and compared each other.

• The Korean Journal of Mycology
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• v.27 no.2 s.89
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• pp.107-111
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• 1999

Vinyl mulching was used on Oyster mushroom beds in an attempt to control bacterial diseases of Pleurotus ostreatus. Beds were covered with perforated, transparent vinyl sheets (0.03 mm thick, 180 cm wide); holes (10 cm diameter) were 10 cm apart. There were $25\;holes/m^2$. Vinyl mulching made management of the crop easier. Discrete mushroom flushes formed with high quality bunches of mushrooms formed through the holes; this made picking quicker and made more efficient use of labor. Total yield of mushrooms increased by 5.7% to $10.8\;kg/m^2$. Mushroom mycelium under vinyl remained healthy and white; whereas mycelium grown using conventional methods changed from white to yellow-brown during the cropping cycle. The mean weight of a mushroom bunch from vinyl mulched beds was 283 g (33 fruitbodies) compared to 117 g (15 fruitbodies) obtained using conventional growing methods.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.3
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• pp.111-120
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• 2015

Recently, self-adaptive system researches have been done to solve the problems occurred in the dynamic environment. Designing requirement in the self-adaptive system is necessary to recognize and solve the problem for the system, and if a developer reuses existing adaptation strategy to design the requirement, the designing time and cost would be reduced. Therefore, this paper proposes the system which extracts reusable adaptation strategy from the existing self-adaptive system. For the proposal, this paper conceptualizes the self-adaptation elements, defines the adaptation strategy ontology and target system ontology, and presents the process of extracting reusable strategy. This paper also implements proposed system and evaluates the reuse rate of the extracted strategy. As a result, the adaptation strategies extracted by proposed system are exactly operated, and the extraction method of proposed system shows higher reuse rate than a previous method.

• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.3
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• pp.119-135
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• 2005

Design of location erea(LA) in a cellular network is to partition the network into clusters of cells so as to minimize the cost of location updating and paging. Most research works dealing with the LA design problem assume that the call. arrival rate and mobile flow rate are fixed parameters which can be estimated independently. In this aspect, most Problems addressed so far are deterministic LA design problems(DLADP), known to be NP hard. The mobile flow and call arrival rate are, however, varying with time and should be treated simultaneously because the call arrival rate in a cell during a day is influenced by the change of a population size of the cell. This Paper Presents a new model on IA design problems considering the time-dependent call arrival and mobile flow rate. The new model becomes a stochastic LA design problem(SLADP) because It takes into account the possibility of paging waiting and blocking caused by the changing call arrival rate and finite paging capacity. Un order to obtain the optimal solution of the LA design problem, the SIADP is transformed Into the DLADP by introducing the utilization factor of paging channels and the problem is solved iteratively until the required paging quality is satisfied. Finally, an illustrative example reflecting the metropolitan area, Seoul, is provided and the optimal partitions of a cell structure are presented.

• The Journal of the Korea Contents Association
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• v.4 no.4
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• pp.89-97
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• 2004

Web-Mail Services are implemented with SMTP and POP3 in these days. These web mail services provide not only the basic sending and receiving functions but also additional functions for user. However, the sent and received data are stored in the web mail server. So general web mail users can't process their mail data if they have not access ID for the web mail server. In this paper, we design and implement WMIS (Web Mail Integration System) using XML. In the proposed system, mail data and user's environments in the old web mail system are transformed into XML documents and inserted into database. In order to store XML data into database, we use dynamic document processing method and analyze XML file by record unit. When the users change their mail accounts, they easily can establish the web environments and their mail data. Because the transformed XML document is converted into WML easily, the WMIS can reduce development cost, labors and time.

• Journal of the Society of Naval Architects of Korea
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• v.33 no.2
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• pp.1-12
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• 1996

Hydrodynamic characteristics of shipping water on deck are investigated by using a simplified two-dimensional model. Formulation of the shipping water on deck leads to a nonlinear hyperbolic system of equations based on the shallow-water wave theory. Time-domain solution of these equations are obtained numerically using a finite difference method which adopts predictor-corrector method for time-marching and 2nd upwind differencing method for convection term calculation. To confirm the validity of the present numerical method, we calculated some shallow-water wave problems accompanying a bore and compared the obtained results with the analytic solutions. We found good agreements between them. Though the calculation results of shipping water on deck, we show that the shipping water flows into the deck as a rarefying wave arid grows into a bore after colliding with a deck structure. Also we examined the effects of acceleration and slope of deck and found that they have significant influences on the flow of shipping water.