• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.140.1-140
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• 2001

In order to survive in today's world of intense market competition, one of the major goals in the manufacture industry is to supply new products in an optimal time frame. To achieve this goal, there is an essential need to shorten delivery time through higher productivity, less trial and error in the designing process, and increase in efficiency in designing new products. For these purposes, AutoCAD is generally used; however, there are two basic limitations. First, AutoCAD requires individual designing for each product, and two, the program does not grant statistical results. The aim of this paper is to present both design and development of Automatic Specification Generation System(ASGS) for metal products. ASGS isan applied designing system that reproduces drawing ...

• Korean System Dynamics Review
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• v.1 no.1
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• pp.103-131
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• 2000

If a system such as a port has a large boundary and complexity, and the system's substance is considered as a black box, forecast accuracy will be very low. Futhermore various components in a port exert significant influence on each other. To copy with these problem the form of structure models were introduced by using SD method. The Competitive Ports Model had several sub-systems consisting of each Unit Port models, and each Unit Port model was made by quantitative, qualitative factors and their feedback loops. The fact that all components of one port have influence on the components of the other ports should be taken into account to construct Competitive Port Models. However, with the current approach that is impossible, and in this paper therefore, models were simplified by HFP adapted to integrate level variables of unit port models. Although many studies on modelling of port competitive situation have been conducted, both theoretical frame and methodology are still very weak. In this study, a new algorithm called ESD(Extensional System Dynamics) for the evaluation of port competition was presented, and applied to simulate port systems in northeast asia.

• Journal of Fisheries and Marine Sciences Education
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• v.21 no.4
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• pp.499-507
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• 2009

The purpose of this study was to improve teachers' instruction and to identify the characteristics of interaction between teachers and children. Field excellent class instructions, which were known as the best lectures from the competition of an instruction contest in Busan, were video recorded and openly released on the internet. A teacher who won a prize for his excellent teaching at the contest demonstrated a Korean subject class on sixth grade elementary school curriculum. His instruction was analyzed by two coders based on the frame of Flanders' language interaction system. Inter-coder reliability was .967 from Scott's coefficient. From the results of the Flanders index, the major and minor instruction sequences were 4-8-2-5 and 6-0-5-4, and the teacher tended to interact with students by accepting feeling and ideas. These results could provide effective cues and information on how to to improve instruction.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2005.09a
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• pp.155-159
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• 2005

High speed presses with high resolution in semiconductor lead frame manufacturing process are needed . But high speed operation accompanies mechanical vibration. therefore optimized kinematic structure to minimize vibration is required for a high speed press. And the growing competition in the industry asks a press with low cost, high speed, high resolution, and high pressing force, For this purpose a high speed press was modeled with 3D CAD solid modeling system and dynamic analysis were performed with CAE S/W for multibody dynamic analysis, Through these analyses a motor appropriate to a high speed press was selected and link structure for feeding system of the press was modified to reduce vibration. To perform this analysis working Model which is 2D kinematics and dynamic analysis software was used.

• Journal of the Korean Institute of Navigation
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• v.23 no.1
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• pp.75-84
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• 1999

Although many studies on modelling of port competitive situation have been conducted, both theoretical frame and methodology are still very weak. In this study, therefore, a new algorithm called ESD (Extensional System Dynamics) for the evaluation of port competition was presented, and applied to simulate port systems in northeast asia. The detailed objectives of this paper are to develop Unit fort Model by using SD(System Dynamics) method; to develop Competitive Port Model by ESD method; to perform sensitivity analysis by altering parameters, and to propose port development strategies. For these the algorithm for the evaluation of part's competition was developed in two steps. Firstly, SD method was adopted to develop the Unit Port models, and secondly HFP(Hierarchical Fuzzy Process) method was introduced to expand previous SD method. The proposed models were then developed and applied to the five ports - Pusan, Kobe, Yokohama, Kaoshiung, Keelung - with real data on each ports, and several findings were derived. Firstly, the extraction of factors for Unit Port was accomplished by consultation of experts such as research worker, professor, research fellows related to harbor, and expert group, and finally, five factor groups - location, facility, service, cargo volumes, and port charge - were obtained. Secondly, system's structure consisting of feedback loop was found easily by location of representative and detailed factors on keyword network of STGB map. Using these keyword network, feedback loop was found. Thirdly, for the target year of 2003, the simulation for Pusan port revealed that liner's number would be increased from 829 ships to 1,450 ships and container cargo volumes increased from 4.56 million TEU to 7.74 million TEU. It also revealed that because of increased liners and container cargo volumes, length of berth should be expanded from 2,162m to 4,729m. This berth expansion was resulted in the decrease of congested ship's number from 97 to 11. It was also found that port's charge had a fluctuation. Results of simulation for Kobe, Yokohama, Kaoshiung, Keelung in northeast asia were also acquired. Finally, the inter port competition models developed by ESB method were used to simulate container cargo volumes for Pusan port. The results revealed that under competitive situation container cargo volume was smaller than non-competitive situation, which means Pusan port is lack of competitive power to other ports. Developed models in this study were then applied to estimate change of container cargo volumes in competitive relation by altering several parameters. And, the results were found to be very helpful for port mangers who are in charge of planning of port development.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.12C
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• pp.280-291
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• 2001

LL (Leased Line service) is a facility-based service as a traditional business data service, but new competition services, such as FR (Frame Relay), VPN (Virtual Private Network), and ATM (Asynchronous Transfer Mode), are value-added services. Because of different service classifications, it is hard to gather necessary data for the service providers to plan their market strategies and regulations and policies are also applied asymmetrically to each service provider. Therefore an appropriate market classification is required for the business data services. After various methods of market classification are reviewed, the Hendry model is selected in this paper to analyze substitution-degree among brands or among services. Since the structure of virtual competitions is required for the Hendry model to be applied to data service market, the market is analyzed first by the well-known Porter's model. By the analysis of Porter's model, two virtual competition structures are set up - one is for the competitions among leased line service providers, and the other is for the competitions among business data services such as LL, FR, VPN and ATM. After the Hendry model is applied to each competition structure, it is confirmed that 7 LL service providers do not compete directly, but 2 sub-markets exist for the LL service provisions. However, it is shown that 4 business data services compete directly. Using the Switching Probability Matrix from Hendry model, future market shares of LL service providers and market shares of business data services are forecasted. These empirical results are helpful for service providers to set competitive strategies with the minimization of cannibalization effect and they can easily and efficiently predict their market demands.

• Journal of the Korea Society for Simulation
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• v.21 no.2
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• pp.1-9
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• 2012

Subterranean termites forage by constructing tunnel networks in soil and encounter food resources during tunnel excavation. Some species of termites can travel up to 150 m underground. They often travel to the surface to find wood cellulose to feed their colony, which in turn causes extensive damage to wooden architecture, such as timber-frame houses. This type of damage has been constantly increasing along with global warming because higher temperatures provide an ecological niche for termites. The damage is closely related to termite territory size and distribution. Recently, as a way to research termite control, the necessity of a mathematical model to simulate termite territory formation in relation to damage has increased. So far, however, few studies have been conducted on the development of a model because it is difficult to quantify or characterize the relationship between territorial behavior and field conditions including complicated environmental factors. In the present study, we suggest a simulation model of the territoriality of the Formosan subterranean termites, Coptotermes formosanus (Shiraki), and Reticulitermes flavipes (Kollar), based on empirical data. The model consists of 2 procedures. One describes tunnel network growth for each colony, and the other represents territoriality based on tunnel-tunnel interactions between different colonies. Using the model, we show changes in territorial competition according to the termination probability of tunnel growth.

• Journal of Korean Society of Water and Wastewater
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• v.10 no.2
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• pp.47-54
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• 1996

UASB reactor was operated for treating wastewater containing high sulfate to assess their performance, competition between sulfate-reducing bacteria(SRB) and methane-producing bacteria(MPB), and the change in the characteristics of microbial granules according to change of hydraulic retention time(HRT) in the reactor. The reactor was fed with a synthetic moderate strength wastes(glucose, 2000 mgCOD/l) containing high sulfate($2400mgSO_4{^{2-}}/l$). The organic loading rate(OLR) ranged from 1.5 to 3.0 gCOD/l.d as HRT maintained 15 to 30 hrs in the stage I. The COD removal efficiency was between 80 to 92%. During this period, methane yield rapidly decreased from 0.3 to 0.1 1 $CH_4$/gCODremoved. While sulfide concentration in the effluent increased from 80 to 200 mgS/l. This indicates that SRB becomes dominant over MPB at a relatively long HRT in the excess sulfate. When OLR of reactor maintained from 5 to 8 gCOD/l.d in the stage II, methane yield increased from 0.1 to 0.17 1 $CH_4$/gCODremoved regardless of decrease of COD removal efficiency. This indicates that SRB is more sensitive to the change of a short HRT than MPB. In the competition between SRB and MPB, about 30% of the removed COD was utilized by SRB at HRT of 30 hrs during the start-up period, while about 73% was used by SRB at HRT of 15hrs at the final step of second experimental stage. Whereas after shock exposure of OLR about 62% was utilized by SRB at HRT of 5hrs. It indicates that SRB is strongly suppressed by the wash-out of significant dispersed SRB since a large electron flow is distributed to the MPB. In addition, the granulation in the presence of high sulfate is unfavoured at a long HRT because of substrate transport limitations into MPB like Methanothrix spp. which is an important factor in the composition of the granules. Accordingly, granule sizes in the UASB reactor decreased with time due to weak network frame of granules by the decreased activity of MPB.

• Korean journal of communication and information
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• v.63
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• pp.5-25
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• 2013

Korean society suffers from severe divisions represented by bi-polarization and collapse of the middle class. Intensive demanding on expanding social welfare budget has emerged in accordance with such a dramatic shift. Social consensus moving toward well-financed welfare policy, however, happens to meet political opposition supported by the discourse of fiscal soundness. This paper thus pays particular attention to deciphering the discursive structure in way of understanding how discourses bring public policy into play. For this purpose, news articles about fiscal soundness collected from 8 national newspapers have been analyzed in terms of frame, attitude, perspective and world view. Research results show, first of all, that there exist persistent competition between two frames identified as 'reduced tax with fiscal discipline' and 'increased tax with welfare money.' While the 'reduced tax' frame favors in maintaining tax cut at the expense of welfare budjet, the frame of 'increased tax' supports such arguments as the flexible employment of fiscal soundness and prosperity of national community helped by widening tax revenues. Also did these frames include a number of sub-frames like welfare populism, partisan politics, trickle down effect, tax bonanza for the rich, universal welfare and market over-reactions in order to bolster its logical authority. Media's active taking a part in penetrating supportive frames in line with political stance was found as well. Taking into account both the discursive structure upheld by frames and politics materialized by the media, the authors argue that public policies should be considered more as discourse than fixed reality. Shedding additional light on understanding the interplay among public opinion, policies and media discourse is of another importance for further study.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.787-790
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• 2015

Recently, M2M (Machine to Machine) communication is possible the development of MTC (Machine Type Communication) devices becomes active. MCT devices in the form of home appliances have a low power consumption, low cost, short-range wireless communication in wireless home network. For purpose, MTC devices based on IEEE 802.15.4/Zigbee are composed in the form of cluster-tree topology, which consists of one PAN (Personal Area Network), one or other router and end of nodes. It happens that transmission delay, packet drop, and lacking data resulted from collision originated by a competition for allocating channels among MTC devices that greatly increased. At last performance of entire network can be degradated. This paper proposes that the beacon frame-based grouping algorithm using multiple channels in a MTC devices in the presence of wireless home network interference. The proposed algorithm decreases the transmission delay, dropped packet and throughput is more increase, so the proposal algorithm is more efficient than the IEEE 802.15.4/ Zigbee standard.