• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.39 no.2
• /
• pp.143-151
• /
• 2003

A series of fishing experiments was carried out in the waters off the east coast of Korea from January, 2002 to March, 2003, using gill nets of different mesh sizes (m = 180, 210, 240, 270, and 300 ㎜) to determine the size selectivity of gill net for male snow crab Chionoecetes opilio. The maximum carapace length (RL) of each male snow crab caught in the fishing experiment was measured. The master curve of mesh selectivity was estimated by applying the extended Kitahara's method. Two kinds of functional models, quadratic function and cubic function were used to express logarithmic selectivity curve and were fitted to the data using the method of least squares. The obtained results were summarized as follows; 1. The cubic function of asymmetry was chosen to determine the selectivity curve of gill net for male snow crab from the model deviance comparison. 2. The result of size selectivity showed that the catch number of small male crab was getting decreased according to the increase of mesh size. 3. The optimum value (RL/m) was 0.549 and the RL/m was estimated to be 0.281, 0.296, and 0.356 when the retention probability were 0.2, 0.25 and 0.5, respectively.

• Journal of the Institute of Convergence Signal Processing
• /
• v.8 no.3
• /
• pp.156-162
• /
• 2007

The parallel beam SPECT system acquires projection data by using collimators in conjunction with photon detectors. The projection data of the parallel beam SPECT system is, however, blurred by the point response function of the collimator that is used to define the range of directions where photons can be detected. By increasing the number of parallel holes per unit area in collimator, one can reduce such blurring effect. This approach also, however, has the blurring problem if the distance between the object and the collimator becomes large. In this paper we consider correction methods for artifacts caused by non-circular orbit of parallel beam SPECT with many parallel holes per detector cell. To do so, we model the relationship between the object and its projection data as a linear system, and propose an iterative reconstruction method including artifacts correction. We compute the projector and the backprojector, which are required in iterative method, as a sum of convolutions with distance-dependent point response functions instead of matrix form, where those functions are analytically computed from a single function. By doing so, we dramatically reduce the computation time and memory required for the generation of the projector and the backprojector. We conducted several simulation studies to compare the performance of the proposed method with that of conventional Fourier method. The result shows that the proposed method outperforms Fourier methods objectively and subjectively.

• Journal of Broadcast Engineering
• /
• v.15 no.2
• /
• pp.205-216
• /
• 2010

In this paper, a method of MPEG-2 Transport Stream (TS) multiplexing for Ultra HDTV (UHDTV) and its design and implementation as a SW tool is described. In practice, UHD video may be divided into several HD videos and each video is encoded in parallel. Therefore, it is necessary to synchronize and multiplex multiple bitstreams encoding each HD video for transmitting and storing UHD video. In this paper, it is assumed that 4 HD videos partitioning a UHD spatially are encoded as H.264/AVC and two 5.0 channel audios are encoded by AC-3. Therefore, 4 H.264/AVC elementary streams (ESs) and 2 AC-3 ESs is mainly considered in the TS multiplexing of UHD. For the carriage of H.264/AVC and AC-3 over MPEG-2 TS, PES packetization and TS multiplexing are designed and implemented based on the extended specification of the MPEG-2 Systems and ATSC (Digital audio compressed standard), respectively. The implemented UHD TS multiplexing tool emulates real time HW operation in the time unit corresponding to the duration of one TS packet transmission in a given TS rate. In particular, in order to satisfy the timing model, the buffers defined in the TS System Target Decoder (T-STD) are monitored and their statuses are considered in the scheduling of TS multiplexing. For UHD multiplexing, two kinds of multiplexing structures, which are UHD re-multiplexing and UHD program multiplexing, are implemented and their strength and weakness are investigated. The developed UHD TS multiplexing tool is tested and verified in terms of the syntax and semantics conformance and functionalities by using a commercial analyzer and real-time presentation tools.

• Korean Journal of Environmental Biology
• /
• v.29 no.1
• /
• pp.17-22
• /
• 2011

The distributional pattern of benthic diatoms in tidal flats of Hampyeong Bay, Korea, was studied from January to October in 2009. As benthic diatoms of Hampyeong Bay tidal flats, 45 species were identified, and the most dominant species was Paralia sulcata. The most diverse flora was observed at Gaip and Songseok sites in April with 22 species, and the least at Hyeonhwa site in January. The ranges of chlorophyll-a concentration in tidal flats were 21.2~31.8 mg$m^{-2}$ at Hyeonhwa site, 23.6~35.4 mg $m^{-2}$ at Gaip site, and 24.2~34.3 mg $m^{-2}$ at Songseok site. The concentrations of pheopigment ranged between 25.3 and 45.2 mg$m^{-2}$. The standing crops of benthic diatoms showed highest density in April and lowest in January, February, and October. The cell volumes of benthic diatoms were highest in April. The taxa and biomass of benthic diatoms showed correlations with temperature. On temperature variables, the benthic diatoms showed optimal occurrences at the range of $14{\sim}17^{\circ}C$.

• Journal of the Korean Geographical Society
• /
• v.31 no.4
• /
• pp.648-661
• /
• 1996

The traditional von Thunen model has various shortcomings. Perhaps the greatest dificiency is the model's sole emphasis on the production side of the economy;that is, the agricultural markets are rarely closed for demand. In thes paoer a closed model for a three-activity, two-dimensional economy is developed. Equillibrium solutions are generated for prices, land areas, and outputs. Comparative static analysis then follows. Attention is next given to a maximum expected-return model under environmental uncertainty. Land uses for the traditional model and the closed model are then compared.

• Korean Journal of Social Welfare
• /
• v.35
• /
• pp.107-131
• /
• 1998

This study tried to formulate and operate an interdisciplinary case management team in Eun-Pyung Gu, Seoul. This was a part of an effort to promote efficiency of service delivery system for low-income elderly or the handicapped by linking. coordinating. and integrating various health and human services providers. In-depth qualitative analysis described the process of which the interdisciplinary case management team was formed, along with the process of the team operation. The interdisciplinary team consisted of home helpers, visiting nurses, and social workers from Health Center and Social Welfare Centers. Issues dealt with by the team include: 1) information exchange of clients' social, economic, and medical situations; 2) identification of types of service provision to clients; 3) clients' needs assessment and its prioritization; 4) assignment of a leading case manager for each case; 5) identification of problems and issues regarding integration of service delivery system The team approach to case management contributed to the systematic delivery of services to the elderly and the handicapped by avoiding service duplication and fragmentation. This study argued that public agency played a key role in constituting and operating the interdisciplinary case management team Suggestions for further studies were presented.

• Journal of Digital Convergence
• /
• v.10 no.11
• /
• pp.427-432
• /
• 2012

The article herein suggested a compound repository and a descriptive method to develop a compound knowledge process. A data target saved in a compound knowledge repository suggested in this article includes all compound knowledge meta data and digital resources, which can be divided into the three following factors according to the purpose: user roles, functional elements, and service ranges. The three factors are basic components to describe abstract models of repository. In this article, meta data of compound knowledge are defined by being classified into the two factors. A component stands for the property about a main agent, activity unit or resource that use and create knowledge, and a context presents the context in which knowledge object are included. An agent of the compound knowledge process performs classification, registration, and pattern information management of composite knowledge, and serves as data flow and processing between compound knowledge repository and user. The agent of the compound knowledge process consists of the following functions: warning to inform data search and extraction, data collection and output for data exchange in an distributed environment, storage and registration for data, request and transmission to call for physical material wanted after search of meta data. In this article, the construction of a compound knowledge repository for recommendation system to be developed can serve a role to enhance learning productivity through real-time visualization of timely knowledge by presenting well-put various contents to users in the field of industry to occur work and learning at the same time.

• Korean Journal of Food Science and Technology
• /
• v.28 no.3
• /
• pp.399-404
• /
• 1996

Encapsulation of lysozyme using lecithin vesicles and its stimilated release properties were studied. Lecithin vesicles were prepared by the dehydration-rehydration (DR)method. The highest encapsulation efficiency (EE) value of 80.1% was obtained by sonicating the multilamellar vesicles (MLVs) at 100 KHz for 120 min in bath sonicator. The value of entrapment progressively increased with the concentration of lysozyme, while the EE value decreased with the increase of enzyme concentration up to 50mg per 100mg per 100mg of lecithin, and then became nearly constant. At the pH of 5.9, only a small amount of lysozyme was released from DR vesicles during incubation at $37^{\circ}C$ As the pH decreased to 3.0, lysozyme was released more rapidly. Lysozyme release was accelerated for 24h and reached a plateau after 72h incubation with 1% Tween 80, $Ca^{2+}$ gave a pulse-like-release in the first hour, which was followed by a slow release.

• Journal of the Korean association of regional geographers
• /
• v.21 no.2
• /
• pp.379-393
• /
• 2015

The fire damage has been increased as the frequency of fire incidence decreases with increasing in death and economic loss. Local governments are dependent on the activities of fire-fighters with crude preparedness and prevention for fire incidence. Most of researches on fire safety have focused on descriptive statistics which show general trends in fire incidence and condition. Here we tried to make a mutual causal model for fire damage, to make three big hypotheses with laying three small hypotheses under each big hypothesis. Five years statistics from public domains in the form of hardcopy or softcopy were collected and fifteen independent variables were selected to explain the number of death, the number of fire incidence and the amount of economic loss from fire incidence. The significances of statistics are different among the regional characteristics. The hypotheses were partially rejected and the meanings of rejected factors will refresh the tentative prejudice. It is necessary to revise the principle that the number of population and size of area are regarded as the most important criteria to allocate resources for fire control and to have the criteria flexible with results of our research such as the number of the weak to fire disaster.

• Journal of Korean Society of Forest Science
• /
• v.104 no.2
• /
• pp.248-253
• /
• 2015

This study applied the portfolio approach as a means to provide decision-making information for the establishment of the optimal production plan for non-timber products. The target items of non-timber forest product were Chestnut, Jujube, Walnut and Astringent Persimmon. The data used in this study were the annual report of forestry production cost survey which contains the annual production, annual gross income, and annual product cost from 2008 to 2013. These data were used to calculate the expected return of non-timber forest product. The objective function in the portfolio models was to minimize the expected return volatility, called risk and the constrain was to achieve the minimum expected return rate. Results indicated that the production ratio of the nuts and fruits in 2013 was 7% for Chestnut, 20% for Jujube, 5% for Walnut and 68% for Astringent Persimmon. Furthermore, portfolio presented that the production ratio was 10% for Chestnut, 9% for Jujube, 3% for Walnut and 78% for Astringent Persimmon in the near future. The cause was analyzed due to maintain stable production and income of Astringent Persimmon and Chestnut. Meanwhile, the revenue of Walnuts and Jujube was in great variation with relatively higher revenues.