• Journal of Navigation and Port Research
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• v.27 no.3
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• pp.283-288
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• 2003

Recently, the growth of applications and services over high-speed Internet increases, ATM networks as wide area back-bone has been a major solution. As the conventional TCP/IP suite is still the standard protocol used to support upper application on current. Internet, the issues regarding whether TCP/IP will operate efficiently on top of an ATM infrastructure and how to control its QoS still remain for studies. TCP uses a window-based protocol for flow control in the transport layer. When TCP uses the UBR service in ATM layer, the control method is only buffer management. If a cell is discarded in ATM layer, one whole packet of TCP will be lost; this fact occur the most TCP performance degradation. Several dropping strategies, such as Tail Drop, EPD, PPD, SPD, FBA, have been proposed to improve the TCP performance over ATM. In this paper, to improve the TCP performance, we propose a packet dropping scheme that is based on comparison with EPD, SPD and FBA. Our proposed scheme is applied to schemes discussed in the previous technology. Our proposed scheme does not need to know each connection's mean packet size. When the buffer exceeds the given threshold, it is based on comparison between the number of dropped packet and the approved packet. Our results are reported and discussed for comparing these discarding schemes under similar conditions. Although the number of virtual channel (VC) is increased, the simulation results showed that the proposed scheme can allocate more fairly each VC than other scheme.

• Journal of Engineering Education Research
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• v.19 no.1
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• pp.47-53
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• 2016

New occupational qualification system built on NCS(National Competency Standard) aimed to induce industries, the final appliers of qualification, to play a leading role in designing qualification and to spontaneously apply such qualification standard to employment and promotion so as to reinforce universality of qualification. In this study, we verified the validity of NCS level of qualification categories for 130 occupational fields by redesigning NCS-based new occupational qualification system with a focus on 7 major areas, including mechanical field, which were found to have wide-ranging social ripple effect throughout society and high acceptability in 2014. The results of study on suitability at qualification level suggested the followings: First, there is a difference in number of competency units for each qualification category, depending on area. New qualification covering 7 major areas included 15.3 competency units for each qualification category, which exceeds the number of competency units(about 10 units) in subdivided NCS. By field, some difference was found with 7.9 competency units for cultural field and 22.6 competency units for information and communication area. Second, preference above normal level was observed in the criteria, procedure and method for determining qualification redesigning. However, preference below normal level was exhibited in connection with possibility of linkage with overseas qualifications, although preference was above normal level in relation to the suitability of design/qualification level and qualification categories based on lifelong career development path within scope of NCS as the criteria for determining the redesign of qualification categories. Second, we compared NCS level and SC(Sector Council level, and the results showed that NCS level was found to be somewhat well-defined. For the qualifications with different definitions, it was deemed difficult to determine superiority between NCS level and SC level. However, majority opinion indicated that it would be desirable to follow NCS level because NCS was created through collection of opinions for a prolonged period.

• 한국디지털정책학회:학술대회논문집
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• 2005.06a
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• pp.107-143
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• 2005

Mobile service that geography, position by development of space Information Technology and technology of communications, space are various to us now becoming limelight as point contents and infra information that customers do demand based on radio superhigh speed authentication net on highly information society by offer infringement problem about individual's privacy or information by political and scientific interest be injured. Purpose of this study grasps use factor of LBS application Mobile service, and it is that analyze actual proof through questionnaire to grasp whether some relation is with value and action determination that is felt of LBS application Mobile service. Distributed all question of 190 copies but disk floret inclination did valid data 171 that clear question and omission remove a lot of questions by type of study among questionnaire of collected 182 wealths. Analyzed factor analysis and authoritativeness to search validity and confidence of questionnaire and used single regression analysis and multiple regression analysis for hypothetical verification. According to verification result, Mobile service that apply position base service usefulness and system quality, adaptedness of Mobile service that apply position base service by leading person affecting in use, acted for connection healthy and felt value is important factor immediately. Usability and social effect, felt expense, privacy did not appear by leading person that keep in mind in this study. Is been related with step that Mobile service that apply position base service is placed. That is, as present childhood, a person who have experience that use service to look for friend is few and usability fairly in last in wide application boundary and this very important person was removed finally in model. This study has sense in terms of study systematically about LBS application service use leading person that is getting into the spotlight worldwide among Mobile service that is injured newly.

• Journal of Korean Neurosurgical Society
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• v.61 no.2
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• pp.277-281
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• 2018

Objective : Craniovertebral junctional anomalies constitute a technical challenge. Surgical opening of atlantoaxial joint region is a complex procedure especially in patients with nuchal deformity like basilar invagination. This region has actually very complicated anatomical and functional characteristics, including multiple joints providing extension, flexion, and wide rotation. In fact, it is also a bottleneck region where bones, neural structures, and blood vessels are located. Stabilization surgery regarding this region should consider the fact that the area exposes excessive and life-long stress due to complex movements and human posture. Therefore, all options should be considered for surgical stabilization, and they could be interchanged during the surgery, if required. Methods : A 53-year-old male patient applied to outpatients' clinic with complaints of head and neck pain persisting for a long time. Physical examination was normal except increased deep tendon reflexes. The patient was on long-term corticosteroid due to an allergic disease. Magnetic resonance imaging and computed tomography findings indicated basilar invagination and atlantoaxial dislocation.The patient underwent C0-C3-C4 (lateral mass) and additional C0-C2 (translaminar) stabilization surgery. Results : In routine practice, the sites where rods are bound to occipital plates were placed as paramedian. Instead, we inserted lateral mass screw to the sites where occipital screws were inserted on the occipital plate, thereby creating a site where extra rod could be bound.When C2 translaminar screw is inserted, screw caps remain on the median plane, which makes them difficult to bind to contralateral system. These bind directly to occipital plate without any connection from this region to the contralateral system.Advantages of this technique include easy insertion of C2 translaminar screws, presence of increased screw sizes, and exclusion of pullout forces onto the screw from neck movements. Another advantage of the technique is the median placement of the rod; i.e., thick part of the occipital bone is in alignment with axial loading. Conclusion : We believe that this technique, which could be easily performed as adjuvant to classical stabilization surgery with no need for special screw and rod, may improve distraction force in patients with low bone density.

• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.4
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• pp.433-445
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• 2014

Single phase voltage source converter (VSC) is an important power electronic converter (PEC), including single-phase voltage source inverter (VSI), single-phase voltage source rectifier (VSR), single-phase active power filter (APF) and single-phase grid-connection inverter (GCI). As the fundamental part of large scale PECs, single-phase VSC has a wide range of applications. In the paper, as first, on the basis of the concept of the discontinuous pulse-width modulation (DPWM) for three-phase VSC, a new DPWM of single-phase VSR is presented by means of zero-sequence component injection. Then, the transformation from stationary frame (abc) to rotating frame (dq) is designed after reconstructing the other orthogonal current by means of one order all-pass filter. Finally, the presented DPWM based single-phase VSR is established analyzed and simulated by means of MATLAB/SIMULINK. In addition, the DPWMs presented by D. Grahame Holmes and Thomas Lipo are discussed and simulated in brief. Obviously, the presented DPWM can also be used for single-phase VSI, GCI and APF. The simulation results show the validation of the above modulation algorithm, and the DPWM based single-phase VSR has reduced power loss and increased efficiency.

• Journal of Korea Port Economic Association
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• v.31 no.4
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• pp.227-240
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• 2015

Asia's cruise industry is growing rapidly with the number of tourists increasing every year. This growth has encouraged intense competition among leading port cities in Asia to retain cruise tourists and cruise lines. The purpose of this study is to analyze the development of the cruise industry around Busan as a hybrid port city and propose new strategies for improving Busan's competitiveness. To achieve these goals, factor analysis and Importance-performance analysis (IPA) are used. The analyses results suggest that the development possibility of Busan as a cruise center is dependent on the improvement of certain factors, including the variety of inland tour options, unique experience, direct service infrastructure, tourist attractions, wide accessibility to other modes, and strong connection to attraction. In addition, the city needs to meet other requirements, including developing various tours, tourist products, and fly & cruise packages and hosting international festivals that can represent Busan and cater to potential cruise customers. Moreover, the city desperately needs to expand its commercial and cultural space by redeveloping its cruise terminals.

• Journal of Environmental Policy
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• v.10 no.4
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• pp.61-80
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• 2011

Through concentrated investments in environmental regulations centered around BOD, which is a biodegradable matter index, and basic environmental infrastructures, national BOD pollution level has continuously improved. Nonetheless, limitations of BOD management system has become evident through nation-wide stagnation and/or increases of refractory organic matters, such as COD, at main drinking water sources, and the need for a new index, which can easily indicate different environmental conditions, has increased. Therefore, this study suggests a new organic management index for a proper management of surface water. $COD_{Cr}$ and TOC were examined as candidates for surface water quality management index, and it was found that TOC was more appropriate than $COD_{Cr}$ as an organic matter management index. Through this study, it was found that TOC possesses following qualities: a more representative index; international acceptability; monitoring program is easier; better availability of analysis techniques; better accuracy and precision of analysis; less time required for analysis; ease of operation; management of disinfection byproducts; connection with present policies; existence of foreign and domestic application case studies; and correlation with water ecosystem.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.10
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• pp.67-75
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• 2013

In this paper, an analytical model is presented for the source/drain parasitic resistance of FinFET. The parasitic resistance is a important part of a total resistance in FinFET because of current flow through the narrow fin. The model incorporates the contribution of contact and spreading resistances considering three-dimensional current flow. The contact resistance is modeled taking into account the current flow and parallel connection of dividing parts. The spreading resistance is modeled by difference between wide and narrow and using integral. We show excellent agreement between our model and simulation which is conducted by Raphael, 3D numerical field solver. It is possible to improve the accuracy of compact model such as BSIM-CMG using the proposed model.

• Journal of Environmental Impact Assessment
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• v.14 no.6
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• pp.387-402
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• 2005

In this study, we tried to predict the change of future land-cover and relationships between land-cover change and geo-spatial information in the Gongju area by using fuzzy logic operation. Quantitative evaluation of prediction models was carried out using a prediction rate curve using. Based on the analysis of correlations between the geo-spatial information and land-cover change, the class with the highest correlation was extracted. Fuzzy operations were used to predict land-cover change and determine the land-cover prediction maps that were the most suitable. It was predicted that in urban areas, the urban expansion of old and new towns would occur centering on the Gem-river, and that urbanization of areas along the interchange and national roads would also expand. Among agricultural areas, areas adjacent to national roads connected to small tributaries of the Gem-river and neighboring areas would likely experience changes. Most of the forest areas are located in southeast and from this result we can guess why the wide chestnut-tree cultivation complex is located in these areas and the possibility of forest damage is very high. As a result of validation using the prediction rate curve, it was indicated that among fuzzy operators, the maximum fuzzy operator was the most suitable for analyzing land-cover change in urban and agricultural areas. Other fuzzy operators resulted in the similar prediction capabilities. However, in the prediction rate curve of integrated models for land-cover prediction in the forest areas, most fuzzy operators resulted in poorer prediction capabilities. Thus, it is necessary to apply new thematic maps or prediction models in connection with the effective prediction of changes in the forest areas.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.5 no.1
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• pp.11-21
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• 1994

The vocal pitch is controlled by the tension, mass, and length of the vocal fold. It is well known that cricothyroid approximation raises the vocal pitch by simulating the contraction of the cricothyroid muscle, and there were so many reports that have noted a relationship between cricothyroid distance and pitch control, but there does not seem to be any single generally accepted theory to account for this connection. It is generally known that the strap muscles are active during low and falling Fo, and the suprahyoid muscles are active during high and raising Fo. These findings can be related to a general picture of the motion of the larynx during changes in Fo, the cricothyroid joint would tend to lengthen the vocal folds, as the larynx moves up and forward, and relax them as it moves back and down. In this study, we suggest that the relationship between anterior cricothyroid distance and fundamental frequency of the larynx was so complex according to the level of larynx and vertebral curvature. The higher the level of larynx, the wider the cricothyoid distance, but there is more greater fundamental frequency even though more wide cricothyroid distance. This phono-menon seems to be due to the multifactors, especially the vertical tension of the conus elasticus or the change of cricothyroid articulation. It is generally known that the crocothyoid and vocal is muscles are very closely related to pitch elevation, but sternohyoid muscle seems to be more closely related to pitch lowering. By this electromyographic studies, the sternohyoid muscle have dual activity to pitch control, increased activity during the low fundamental frequency and falling pitch, but also increased activity during the higher fundamental frequency and raising pitch at least in this study.