• Journal of the Korean Operations Research and Management Science Society
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• v.41 no.3
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• pp.75-96
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• 2016

This paper investigates the usefulness of drones in an urban delivery system. We define the vehicle and drone routing problem with time window (VDRPTW) and present a model that can describe a dual mode delivery system consisting of drones and vehicles in the metropolitan area. Drones are relatively free from traffic congestion but have limited flight range and capacity. Vehicles are not free from traffic congestion, and the complexity of urban road network reduces the efficiency of vehicles. Using drones and vehicles together can reduce inefficiency of the urban delivery system because of their complementary cooperation. In this paper, we assume that drones operate in a point-to-point manner between the depot and customers, and that customers in the need of fast delivery are willing to pay additional charges. For the experiment datasets, we use instances of Solomon (1987), which are well known in the Vehicle Routing Problem society. Moreover, to mirror the urban logistics demand trend, customers who want fast delivery are added to the Solomon's instances. We propose a hybrid evolutionary algorithm for solving VDRPTW. The experiment results provide different useful insights according to the geographical distributions of customers. In the instances where customers are randomly located and in instances where some customers are randomly located while others form some clusters, the dual mode delivery system displays lower total cost and higher customer satisfaction. In instances with clustered customers, the dual mode delivery system exhibits narrow competition for the total cost with the delivery system that uses only vehicles. In this case, using drones and vehicles together can reduce the level of dissatisfaction of customers who take their cargo over the time-window. From the view point of strategic flexibility, the dual mode delivery system appears to be more interesting. In meeting the objective of maximizing customer satisfaction, the use of drones and vehicles incurs less cost and requires fewer resources.

• Journal of Korea Technology Innovation Society
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• v.10 no.2
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• pp.361-382
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• 2007

As the Korea's economy grows bigger and its industrial structure advances, demands of high quality product become increasing. And the technology becomes to be more important factor than labor power and capital. And, the development of technology plays the key role in promoting the competitiveness of a nation. Measurement means 'Measuring with instrument', dissemination of measurement standards related with dissemination and distribution of measuring instrument. Measurement technology has been known to be the main factor of economic growth and technological development. National measurement standards is one of these factors of measurement technology. Therefore, in order to enhance dissemination of measurement standards to industry, we have to define its economic impact. We analysed the economic impact of measurement standards in terms of its contribution to the product induction of industry and management results using I-O Table with the quantitative data. The results from this study show that the increasement of measurement standards dissemination is in complementary relation with the productivity of various industries, assembly manufacturing, in particularly.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.50-50
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• 2014

We present a new catalog of galaxies in the wider region of the Virgo cluster, based on the Sloan Digital Sky Survey (SDSS) Data Release 7. The Extended Virgo Cluster Catalog (EVCC) covers an area of 725 deg2 or 60.1 Mpc2. It is 5.2 times larger than the footprint of the classical Virgo Cluster Catalog (VCC) and reaches out to 3.5 times the virial radius of the Virgo cluster. We selected 1324 spectroscopically targeted galaxies with radial velocities less than 3000 km s-1. In addition, 265 galaxies that have been missed in the SDSS spectroscopic survey but have available redshifts in the NASA Extragalactic Database are also included. Our selection process secured a total of 1589 galaxies of which 676 galaxies are not included in the VCC. The certain and possible cluster members are defined by means of redshift comparison with a cluster infall model. We employed two independent and complementary galaxy classification schemes: the traditional morphological classification based on the visual inspection of optical images and a characterization of galaxies from their spectroscopic features. SDSS u, g, r, i, and z passband photometry of all EVCC galaxies was performed using Source Extractor. We compare the EVCC galaxies with the VCC in terms of morphology, spatial distribution, and luminosity function. The EVCC defines a comprehensive galaxy sample covering a wider range in galaxy density that is significantly different from the inner region of the Virgo cluster. It will be the foundation for forthcoming galaxy evolution studies in the extended Virgo cluster region, complementing ongoing and planned Virgo cluster surveys at various wavelengths.

• Journal of Acupuncture Research
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• v.19 no.6
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• pp.1-11
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• 2002

Objective : Korean medicine treatment method is noted as alternative in treating traffic accidents(TA) victims recently. The main purpose of this research is to make a survey of the effective way of the Korean medicine treatment about TA victims. Methods : In following research, 389 cases of traffic victims who hospitalized in the Youngsaeng Korean Medicine Hospital & Youngsaeng Clinic from March 1, 2001 to November 30, 2001 were surveyed. The research is focused on finding out the distribution, such as sex and age, damaged part of the body of 389 TA victims, nature of damage of 389 TA victims, chief complaint of 389 TA victims, nature of damage by Korean medicine code classification, treatment given to 389 TA victims, Extract(Ex) medicine given to 389 TA victims, days in hospital of 389 TA victims. Results : The patients reached korean medicine hospital in fewer numbers from most of TA victims. As neck pain and L-spin sprain, most of symptoms was light and the treatment of medicine as well was limited for TA. The treatment method which was used for treating TA was acupuncture, cupping therapy, physical therapy, Ex medicine. Few ways could use the Ex medicine as well. Conclusions : The achieving rate of treatment was marked highly by using Haenggi(行氣) Hwalhyeol(活血) Guyea(祛瘀) and we confirmed a possibility for the treatment of TA in korean medicine treatment method. It needs to increase all kinds of treatment-ways which can treat successfully and needs to come into application of insurance. Korean medicine method will have possibility to take part in TA injury admission, by presenting basis to prove effectiveness of treatment-ways.

• Journal of the Korean Society of Costume
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• v.56 no.3 s.102
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• pp.116-128
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• 2006

The purpose of this study is to investigate Seon expressed in the costume of Chinese Song. For the purpose, this researcher classified types of Seon, found in the Chinese costume, in terms of composition method, decorative technique and used materials. In addition, the researcher attempted to analyze formative characteristics of Sean in accordance with the range and post of use, pattern and color combination. Seon expressed in the costume of Chinese Song can be classified into standard, decoration, application and Buseon in type. When the typical distribution of Seon expressed in the costume of Chinese Song, standard type was highest in percentage, especially different color type. Looking at the range of use, Seon was mainly used for outfits, especially Jikcheol(直?) and Hakchangeui for men and Baeja(背子) for women. Looking at the post of use, Seon was mainly used to edges of costume and sometimes also to seams. In regard to materials of Seon, they were selectively used depending on the existence or non-existence, size and brilliance or non-brilliance of pattern employed in the texture of Seon. The most commonly used pattern of Seon was single-type pattern, especially the pattern of plant. Pattern arrangement was most often filling in type. Concerning the color combination of Seon, men's dress most often used black-white combination, followed by different color combination while, women's dress most often employed complementary color combination, followed by different color combination.

• Journal of Advanced Navigation Technology
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• v.16 no.2
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• pp.234-239
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• 2012

Next generation mobile communication systems have been studied and applied to support various services. In next generation mobile communication systems, the most interested research is the integration of various communication systems and the offer of various services by using high-speed data transmission. The integration of communication systems has been researched by using multi standard modem, while the high-speed data transmission for the offer of various services has been applied by using OFDM. This paper has proposed the method to reduce PAPR by using multi standard modem. with EVM, this paper has also suggested the method to compensate in-band distortion while reducing PAPR. By using the proposed methods, this paper has analyzed and simulated the decrease efficiency of PAPR, the performance of CCDF, and the performance of BER in next generation mobile communication systems. The simulation results improved the performance of next generation mobile communication system can be seen that.

• Korean Journal of Organic Agriculture
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• v.20 no.4
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• pp.491-502
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• 2012

The world's food production systems are becoming an area of great concern for both human and ecological health. Research has identified that one of the greatest threats to sustainability is conventional industrial agricultural systems and the high energy and material cost they require to function. The organic food movement is contributing as promising alternative to the current dominant model. Over the last 50 years it has developed into the most visible brand for a healthier and more environmentally sustainable food system. However, to achieve its full potential there are still a number of hurdles which must be overcome to make organic products a more viable and appealing option for consumers. This paper provides an overview of key research that has been conducted on why consumers are buying organic products, what they are buying and what is preventing them from purchasing more. It concludes that the key challenge is for the organic food movement to convince existing consumers of the superior 'value' of its products. In addition there are a number of methodological issues associated with analysing the market for organic products as well as issues of limited distribution, intermittent availability and high prices that are currently preventing increases in sales. Recognition and management of these barriers could contribute to more effective targeted research into consumer food purchasing motivations and subsequently the development of more sophisticated marketing strategies that assist in maintaining integrity with consumers and fending off challenges from conventional as well as other complementary food systems such as local food movement. And finally to achieve these market growth strategies the organic food movement will need to cope with its diverse constituency - ranging from global corporates through to local production and consumption - and provide attractive opportunities to individuals and business at all stages in supply chain whilst retaining credibility with government to ensure ongoing policy support.

• Journal of Biosystems Engineering
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• v.39 no.1
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• pp.57-67
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• 2014

Purpose: The modern IT can give enormous impacts on the agricultural production and consumption. However, farmer's ability to use IT devices has been known as one of the critical factors on success of IT in agriculture. This survey study was performed to evaluate the informatization status of farmers and to draw a strategy to develop and distribute a ubiquitous agricultural information system. Methods: A survey questionnaire with 19 questions on the degree of IT devices such as computers and smartphones and their utilization were developed. The survey was questioned 3 groups of farmers in Gyounggi Province and analyzed statistically by the ${\chi}^2$ test. Results: The order of IT devices distribution were computers, smartphones, smart TVs and tablet PCs in all groups. The ratios of ownerships of the devices are 97.7, 78.6%, 31.4%, 17.8% respectively. The active farmers in this survey showed higher informatization level than that of native and the general farmers. Conclusions: The ubiquitous agricultural information system was judged to be developed for the computer because spread and use of it exceeds the other devices. Also, the information system based on the smartphone could be a complementary way if the rapid of the smartphones continues and proper education on use of the phone is provided.

• Journal of the Earthquake Engineering Society of Korea
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• v.7 no.2
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• pp.59-66
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• 2003

A novel application of nano-technology in the field of engineering, called colloidal damper, is investigated. This device is complementary to the hydraulic damper, having a cylinder-piston construction. Particularly for colloidal damper, the hydraulic oil is replacedby a colloidal suspension, which is consisted from a nano-porous matrix with controlled architecture and a lyophobic fluid. In this experimental work, the porous matrix is composed from silica gel, with labyrinth architecture, coated by organo-silicones substances in order to achieve a hydrophobic surface. Water is considered as associated lyophobic fluid. The colloidal damper test rig and the measuring technique of the hysteresis are described. the influence of the hydrophobicity level upon the colloidal damper hysteresis is investigated, for silica gels with similar pores distribution. A certain desired shape of the hysteresis can be achieved by employing mixture of silica gels with different level of hydrophobicity and/or architecture. With these results, it is believed that the proposed damper can be designed and be applied to the desired structure.

• Korean Journal of Social Welfare
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• v.65 no.1
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• pp.201-226
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• 2013

This study aims to identify changes in early work career of youth cohort entering the labor market pre and post-the economic crisis and compare career pathway types of different cohorts. Labor market experiences of youth cohort were constructed by sequencing the number of organizations, kinds of jobs, the scale of the business, and type of employment. In addition, a holistic sequence was created by including complementary factors. In this sense, the labor market experience in this study was conceptualized as a process involving continuous sequences and hierarchical and orderly changes which differs from a simple job mobility. Sequence analysis involving Optimal Matching method was conducted to examine whether such cohort-differences in labor market experiences were related to differences in distribution of career pathway types. The result showed that the post-economic crisis cohort had a relatively higher likelihood of falling into the non-employment type, unemployment type, non-corporate employment type, irregular employment type, and mobile employment type. These findings provide empirical evidence supporting the hypothesis that the employment precariousness of cohort has exacerbated after the economic crisis.