• Journal of Korean Society of Transportation
• /
• v.25 no.3
• /
• pp.145-154
• /
• 2007

Determining stop spacing is a very important process in transit system planning. This study is involved in an analytical approach to decide the transit stop spacing. Transit stop spacing should be longer as 1) user access speed, 2) user travel time, and 3) dwell time increase, and shorter as 1) passengers (boardings and alightings) and 2) headway increase. In this study, a methodology is proposed to determine transit stop spacing to minimize total cost (user cost plus operator cost) with irregular passenger distribution (boardings and alightings) Without considering in-vehicle passengers, the transit stop spacing should be shorter in the concentrated sections of the passenger distribution than in others to minimize total cost. Through the conceptual analysis, it is verified that the transit stop spacing could be longer as the in-vehicle passengers increase in certain sections. This study proposes a simple practical method to determine transit stop spacing and locations instead of a dynamic programming method which generally includes a complex and difficult calculation. If the space axis is changed to a time axis. the methodology of this study could be expanded to analyze a solution for the transit service (or headway) schedule problem.

• Journal of Korea Port Economic Association
• /
• v.29 no.2
• /
• pp.81-111
• /
• 2013

Along with a general growth in living standards there has been a corresponding increase in the demand for tourism. Cruise based tourism, in particular, has become one of the most dynamic and dramatic growth sectors in the tourism industry over the last 20 years, including in the Northeast Asian region. In line with the growth of passenger numbers, the number of cruise ships and their berth capacities has increased significantly since the late 1970s. Korea, as a peninsular nation, has also experienced a rapid growth in cruise passenger numbers. The national economy has greatly benefited from this as the industry acts as an income generator, creating new jobs and potential investments and in developing local tourism. Ports play an important role in the development of any national cruise industry, providing not only ship berths but supply and bunkering facilities and a gateway to local tourism opportunities. The selection of the optimal cruise port location is an important and complex problem because the decision makers have to consider a large number of criteria which have a significant effect on the economy, environment, human life, and society. This paper investigates those criteria that are significant in developing a successful cruise port by employing a questionnaire survey of major cruise port users - shipping companies and tourism companies. The ports, surveyed in this study are Busan, Incheon, Yeosu and Jeju. All have been identified as important potential cruise ports in the Korean Government's 'The 3rd Port Basic Plan (2011-2020)'.

• Journal of Environmental Policy
• /
• v.8 no.1
• /
• pp.97-127
• /
• 2009

In Germany, North Sea and East Sea possess significant meaning in many aspects. North coast has an important economical significance to North Sea Gulf States. There are a number of harbors and manufacturing facilities in this area. Agriculture is also developed. East sea, where sea water and river water mingle. has a problem that it can not control harmful substances as fast as the North Sea due to its geographical location of being connected with the North Sea as a narrow water. To protect from big and small ship accidents and pollution sources, East Sea and North Sea have enacted HELKOM Convention and OSPAR Convention, respectively. Moreover, Denmark and Germany have made cooperation on tugboats in the occurrence of shipment accidents through the LethGer-Plan and DenGer-Plan. In 1998, after the Pallas accident that occurred near Bremen, the need to improve cooperation among each states on usable resources for ocean security has been increased in Germany. Consequently, the federal government and gulf state governments associated and organized the so called, "Havarie-Kommanando Ship Accident Measure Unit". Haravarie-Kommanando is a federal-state associated organization that deals with affairs that controls national operation and mobilization of ship accident related organizations unitively when serious ship accidents occur. Moreover, federal and state participant organizations, each shipping agencies and Wiking-Helicopers-Services, a helicopter agency, are cooperating well. Also, mutual assistance with the most prominent passenger agency called Scandlines, ARGE Kuestenschutz(Germany-Denmark shipping agency) is making progress as well.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.15 no.2
• /
• pp.149-162
• /
• 2005

This paper suggest a way to detect a specific wanted figure in public places such as subway stations and banks by comparing color face images extracted from the real time CCTV with the face images of designated specific figures. Assuming that the characteristic of the surveillance camera allows the face information in screens to change arbitrarily and to contain information on numerous faces, the accurate detection of the face area was focused. To solve this problem, the normalization work using subsampling with $20{\times}20$ pixels on arbitrary face images, which is based on the Perceptron Neural Network model suggested by R. Rosenblatt, created the effect of recogning the whole face. The optimal linear filter and the histogram shaper technique were employed to minimize the outside interference such as lightings and light. The addition operation of the egg-shaped masks was added to the pre-treatment process to minimize unnecessary work. The images finished with the pre-treatment process were divided into three reception fields and the information on the specific location of eyes, nose, and mouths was determined through the neural network. Furthermore, the precision of results was improved by constructing the three single-set network system with different initial values in a row.

• Journal of The Korean Association of Information Education
• /
• v.17 no.3
• /
• pp.277-290
• /
• 2013

As the deployment of digital learning environment has been accelerating in rapid changes in information and communications technology, a tool is required to practically measure and evaluate the level of information education (IE) for freshmen in the University in order to propose an appropriate direction of IE in a teachers college. According to such current trends, ICT literacy is a tool to assess a specific level of capabilities such as a variety of real-world problem-solving skills, creativity, critical thinking, analytic reasoning, and communication skills. This study has developed a test tool to measure ICT literacy competence on the basis of the concept of test questions defined from the previous research. It was used to measure ICT literacy competence of 360 university freshmen of education and analyze if there is a difference among them depending on overall ICT literacy levels and genders, content areas, competence factors, and completion of IE course in high school. The result of this study would be expected to determine the current location of IE for freshmen in the University of Education and to be able to take advantage of basic data of the direction for IE course that university students need to essentially acquire in preparation for the coming future.

• The Journal of Bigdata
• /
• v.4 no.2
• /
• pp.159-173
• /
• 2019

Last-Mile delivery optimization plays a key role in the urban supply chain operation, which is the most expensive and time-consuming and most complicated part of the whole delivery process. The urban consolidation center (UCC) is regarded as a significant asset for supporting customer demand in the last-mile delivery service. It is the key benefit of UCC to improve the load balance of vehicles and to reduce the total traveling distance by finding the better route with the well-organized multi-leg vehicle journey in the urban area. This paper presents the model using multiple scenario analysis integrated with mathematical optimization techniques using Geographic Information System (GIS). The model aims to find the best solution for the distribution network consisted of DC and UCC, which is applied to the case of Ulaanbaatar Mongolia. The proposed methodology integrates two sub-models, location-allocation model and vehicle routing problem. The multiple scenarios devised by selecting locations of UCC are compared considering the general performance and delivery patterns together. It has been adopted to make better decisions the quantitative metrics such as the economic value of capital cost, operating cost, and balance of using available resources. The result of this research may help the manager or public authorities who should design the distribution network for the last mile delivery service optimization using UCC within the urban area.

• The Journal of Korean Academy of Prosthodontics
• /
• v.46 no.6
• /
• pp.569-576
• /
• 2008

STATEMENT OF PROBLEM: While patient-centered outcomes are usually not reported, these may represent major aspects of the implant success for the patient. Use of a well-designed patient survey form can be an invaluable asset to the implant practitioners. PURPOSE: The objective of this study was to investigate patient satisfaction after implant therapy by means of a questionnaire. MATERIAL AND METHODS: South Korean patients (n = 100), who visited the dental examination center of Soon Chun Hyang university hospital, were asked to fill out the satisfaction questionnaire regarding aspects of cost, comfort, esthetics, chewing, gingival health, food impaction, phonetic aspect, screw loosening, and general satisfaction. Responses to statements were given on the Likert response scale. Four experimental groups of patients were distinguished with various location ($A_1,\;A_2,\;A_3$), year ($B_1,\;B_2,\;B_3$), number of implant replacements ($C_1,\;C_2,\;C_3$), and treatment cost ($D_1,\;D_2,\;D_3$). The reliability of the response scales was measured by calculation of its internal consistency, expressed as Cronbach's ${\alpha}$. The scales were distinguished by means of factor analysis method. Possible differences in scale scores among the groups were assessed by One-way ANOVA (${\alpha}$= 0.05). RESULTS: Patients responded to most of the statements with high satisfaction. But the mean scale score of statement about cost was low. After the verification of internal consistency and factor analysis, five components, e.g. general satisfaction, comfort, chewing efficiency, esthetics, and phonetic aspect were grouped together. These components could be explained with common meaning and the first factor was named as 'general satisfaction'. Differences in patient satisfaction on the scale with esthetics were present between patients who have been wearing the implant prosthesis less than three years and those more than seven years ($B_1<B_3$). CONCLUSION: The patients were generally satisfied with the outcome of implant treatment. But the patients' major complaint was high cost and while the statistically significant difference was not shown, the satisfaction scale about food impaction and esthetics was low. So the continuing efforts to make improvements about these problems are needed for the implant practitioners.

• Journal of Technologic Dentistry
• /
• v.38 no.1
• /
• pp.23-36
• /
• 2016

Purpose: The purpose of this study is to suggest direction for dental technicians and management of dental laboratories to contribute to the improvement of oral health of citizens with high-quality dental prosthesis by researching operational status and management satisfaction of dental laboratories. Methods: In order to investigate operational status and management satisfaction of dental laboratories, this study conducted a questionnaire survey by mailing questionnaires to heads of dental laboratories designated as clinical training workshops of Department of Dental Technology of G University and a total of 158 questionnaires were used for analysis. Results: As for gender, males were 142 persons (89.9%) and females were 16 persons (10.1%). For location of the laboratories, number of laboratories in metropolitan cities was 94 (59.5%) while small and that in mid-sized cities was 64 (40.5%). As for the satisfaction with job, those who have managed dental laboratories for 23-30 years ($1.92{\pm}77$), transact with 7-12 dental clinics ($1.70{\pm}75$), had monthly income of 4-8 million won ($1.74{\pm}.80$) and had 8-10 employees ($2.33{\pm}.68$) were the highest in their satisfaction. As for satisfaction with management, those who have managed their business for 15-20 years ($2.86{\pm}.52$), transact with more than 20 dental clinics ($2.00{\pm}.04$), had monthly income of less than 4 million won ($2.00{\pm}.85$) and had less than 3 employees ($2.00{\pm}.62$) were the highest in their satisfaction. As for monthly income, those with less than 2 million won were 24 persons (15.2%), 2-4 million were 64 persons (40.5%), 4-6 million were 40 (25.3%), 6-8 million were 14 (8.9%) and over 8 million won were 16 persons (10.2%). As for number of employees, those with less than 3 employees were 32perosns (20.3%), 4-7 were 82 (51.9%), 8-10 were 26 (16.5%) and more than 11 were 10 persons (6.3%). As for severance payment, 84 persons practiced it according to Labor Standard Act (53.2%) and 34 practice it to a proper degree (21.5%) while 20 did not practice it at all (12.7%) and 20 persons did not respond to the question (12.7%). Conclusion: Although dental laboratories have rapidly expanded in number from 473 in 1986 to 2,400 in 2015, dental technician circles are facing difficulty in their management due to fierce competition and low profitability. Therefore, in order to improve this problem, it is necessary to readjust prices for dental prosthesis to realistic ones.

• Journal of electromagnetic engineering and science
• /
• v.9 no.2
• /
• pp.85-97
• /
• 2009

As operating frequency is raised and as more integration with active and passive elements is required, it becomes difficult to fabricate more than 120 ${\Omega}$ characteristic impedance of a mierostrip line. To solve this problem, an equivalent high impedance transmission-line section is suggested, which consists mainly of a pair of coupled-line sections with two shorts. However, it becomes a transmission-line section only when its electrical length is fixed and its coupling power is more than half. To have transmission-line characteristics(perfect matching), independently of coupling power and electrical length, two identical open stubs are added and conventional design equations of evenand odd-mode impedances are modified, based on the fact that the modified design equations have the linear combinations of conventional ones. The high impedance transmission-line section is a passive component and therefore should be perfectly matched, at least at a design center frequency. For this, two different solutions are derived for the added open stub and two types of high impedance transmission-line sections with 160 ${\Omega}$ characteristic impedance are simulated as the electrical lengths of the coupled-line sections are varied. The simulation results show that the determination of the available bandwidth location depends on which solution is chosen. As an application, branch-line hybrids with very weak coupling power are investigated, depending on where an isolated port is located, and two types of branch-line hybrids are derived for each case. To verify the derived branch-line hybrids, a microstrip branch-line hybrid with -15 dB coupling power, composed of two 90$^{\circ}$ and two 270$^{\circ}$ transmission-line sections, is fabricated on a substrate of ${\varepsilon}_r$= 3.4 and h=0.76 mm and measured. In this case, 276.7 ${\Omega}$ characteristic impedance is fabricated using the suggested high impedance transmission-line sections. The measured coupling power is -14.5 dB, isolation and matching is almost perfect at a design center frequency of 2 GHz, showing good agreement with the prediction.

• Journal of the Economic Geographical Society of Korea
• /
• v.1 no.2
• /
• pp.71-84
• /
• 1998

Health has been seen as a resource necessary for both maintaining oneself and for living in a society pursuing high quality of life. Therefore, the medicare provision takes place of one of the most significant indexes for evaluating the regional welfare level. The purpose of this study is to investigate the locational characteristics of medicare service facilities. For the purpose, the distribution patterns of the medicare resources are analyzed both at the regional and local scales. The medicare resources are concentrated at the Metropolitan Seoul area in the regional scale, and they are also concentrated at the economic core areas in the local scale. Especially, higher level medicare resources, such as the general hospitals and medical specialists, show more concentration at the economic core areas than lower level services. This means that access to opportunities to receive higher level medicare is poorer in a more socially disadvantaged area. Since medicare service facilities are invested and operated by both private and public sectors, whose locational mechanisms are deferent, we analyzed the distribution patterns. Most medicare facilities are invested and managed by private sector in Korea, which is operated by market mechanism. This is related with the fact that the medicare facilities are concentrated at the economic core areas. The proportion of private sector is higher in the Metropolitan Seoul area, and thus this region shows stronger spatial disparity of medicare provision. In general, the medicare service facilities are located in the hierarchical structure, and thus the services levels and facility scales are differentiated by the hierarchy. We examined the hierarchical structure in the medicare service facilities in Korea. The referral medicare system has been applied with the assumption of the three level hierarchical structures in Korea. However, we could not find any distinct hierarchical structure in the scales of the medical service facilities.