• 대한산업공학회지
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• 제32권3호
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• pp.163-171
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• 2006

This paper considers a scheduling problem to minimize the sum of the associated scheduling (production/delivery times) cost and the delivery cost for an integrated system of a single production machine and various transportation vehicles with transportation mode selection allowed. Each transportation mode is provided with a fixed number of vehicles at the associated delivery time and cost. The proposed problem is characterized as being NP-hard. Some solution properties are also characterized. Therewith, three heuristic algorithms (called SPT-based, LWF-based and WSPT-based heuristic) and a branch-and-bound algorithm are derived. In order to evaluate the effectiveness and efficiency of the proposed algorithms, computational experiments are made with some numerical instances.

• 무역상무연구
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• 제16권
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• pp.295-329
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• 2001

The wonderful new world of shopping - being able to order items you need by just one click. However, there is one factor that has not changed at all - customers, whether they are private individuals or public companies, want to have the product delivered to their address, and usually as fast as possible too. To achieve this, the operators of virtual shops must make use of a fully operational and efficient delivery service. The internet and its potential for creating a virtual market for millions of buyers and sellers, has generated a lot of excitement in the express delivery industry. Clearly e-commerce will cause greater growth in the business-to-residential package market. Korean express delivery industry is not an exception to this trend. Currently, while major three service providers enjoy a lion's share in Korea, a lot of small and medium companies are struggling to capture more shipments in express parcel market. Nevertheless, it will be forecasted that Korean parcel market will be consolidated and become an oligopoly market in the near future.

• 산업기술연구
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• 제20권B호
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• pp.77-86
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• 2000

In order to observe the pattern forming of copper plate and chemical corrosion reaction, a study on the effect of the process parameters on the formation of micro-pattern by a photochemical etching of copper plate was carried out. The results are as follows : 1) Etching rate increases as the concentration of etchant increases under the regular condition of the temperature by the increasing of diffusion rate to surface. 2) Etching rate increases as the temperature of etchant increases by the fast acting of the material delivery of diffusion to surface under the regular condition of concentration. 3) It was found that etching speed increases as the material delivery of convection rising increased when the aeration speed of etchant increases. This result was from the fact acted by the material delivery of convection rising rather than material delivery of diffusion to the surface.

• 한국항해항만학회지
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• 제29권4호
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• pp.305-312
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• 2005

Pick-up/delivery of consumer goods to offices, shops, and restaurants in order to support urban lives is one of the most vital activities in a city. With economic growth and technological innovation, a greater variety of goods have come to be supplied, and pick-up/delivery of consumer goods has become more complex. Efficient urban goods movement in Central Business District(CBD} starts with an efficient system for loading/unloading, and pick-up/delivery activities. Loading/unloading activity may be carried out on-street, or on especially designated space inside or outside buildings. Therefore, purpose of this study is to clarity the efficient urban goods movement in CBD(also called the pick-up/delivery activity) from the three different types of loading/unloading facilities. For this purpose, the differences in loading/unloading and truck-trip activity time of each loading/unloading facility was compared by performing the simulation analysis.

• Advances in nano research
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• 제14권3호
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• pp.247-259
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• 2023

Muscle strength and hypertrophy are equivalent when low-intensity resistance exercise is paired with blood flow restriction. This paper deals with the impact of physical exercise in the form of body activities on drug delivery using nanodevices. The body's actions impact the blood flow since the nano drug delivery devices are released into the bloodstream, and physical exercise and all the activities that change the blood flow influence the stability of these nanodevices. The nanodevice for the drug delivery purpose is modeled via nonuniform tube structures based on the high-order beam theory along with the nonlocal strain gradient theory. The nanodevice is made by a central nanomotor as well as two nanoblade in the form of truncated conical nanotubes carrying the nanomedicine. The mathematical simulation of rotating nanodevices is numerically solved, and the effect of various parameters on the stability of nanodevices has been studied in detail after the validation study.

• Educational Technology International
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• 제24권1호
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• pp.29-51
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• 2023

This study examined the moderating effect of course satisfaction with class on the relationship between the mode of course delivery and learning presence and performance in university settings. Results showed that there was a moderating effect of the course satisfaction on the relationship between course delivery mode and learning presence. Specifically, higher satisfaction with instructor's teaching activities was associated with improved learning presence in face-to-face, blended, and online learning, in that order. However, there was no significant moderating effect on academic performance. These findings suggest that universities should consider not only the mode of course delivery and highlight the importance of systematic course design by instructors.

• 한국지역지리학회지
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• 제10권1호
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• pp.158-176
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• 2004

본 연구는 오프라인을 기반으로 한 인터넷 쇼핑몰의 유통체계와 상품판매의 공간적 특성을 밝히는 것이 목적이다. 본 사례업체의 유통체계는 크게 메이커에서의 상품 선정과정과 소비자로의 상품 배송과정으로 구분된다. 이는 물류센터의 기능과 역할을 모두 위탁한 결과이다. 또한 오프라인인 백화점과 구별된 물류시스템을 이용하고 있으며 비용절감과 보다 빠른 배송을 위해 배송부문을 택배사에 외부수주하고 있다. 배송권별 상품판매의 특성을 살펴보면 본사가 입지한 배송권에 상품판매가 집중적으로 이루어지는 형태를 보인다. 이는 오프라인을 기반으로한 인터넷 쇼핑몰이 공간의 제약을 완전하게 극복한 통신판매가 아님을 말해 주는 것이다. 또한 지역별 상품 판매에 영향을 미치는 공간적 분포 요인은 20$\sim$49세의 여성인구수와 거리임이 밝혀졌다.

• 제어로봇시스템학회논문지
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• 제20권12호
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• pp.1181-1188
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• 2014

In this paper, we propose a novel concept foran unmanned delivery service using a cooperative heterogeneous unmanned system consisting of a self-driving car and an unmanned aerial vehicle (UAV). The proposed concept is suitable to deliver parcels in high-density and high-rise urban or residential areas. In order to achieve the proposed concept, we will develop acooperative heterogeneous unmanned system. Customers can order goods using a smartphone application and the order information, including the position of the customer and the order time, and the package is transported automatically by the unmanned systems. The system assigns the tasks suitable for each unmanned vehicle by analyzing it based on map information. Performance is validated by experiments consisting of autonomous driving and flight tests in a real environment. For more evaluation, the landing position error analysis is performed using circular error probability (CEP).

• 한국시스템다이내믹스연구
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• 제17권1호
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• pp.5-24
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• 2016

This study structurally analyzes major inefficiency of Korea's healthcare delivery system by utilizing the systems thinking. In particular, the phenomenon of patient's concentrated visits to large hospitals, waste of resource due to competitions between clinics and large hopitals, and the structure of oversupply were visualized using the causal loop diagram. The inefficient structure of healthcare delivery system can be understood more clearly by utilizing the major system archetypes of 'success to the successful', 'tragedy of commons', 'escalation' and 'limits to growth'. This study also finds solution from archetypal structure suggested by Wolstenholme. The inefficient status of healthcare delivery system might be explained by the 'out of control' archetype. In conclusion, the public resources such as the national health insurance need to be acknowledged as the entire achievement. All the participants should cooperate with each other in order to improve the inefficiency of the healthcare delivery system. In addition, the arrangement of incentive system for cooperation, acceleration of health information technology, and development of innovative business models make the sustainable healthcare delivery system.

• 한국IT서비스학회지
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• 제9권2호
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• pp.151-161
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• 2010

Recently, as the era of ubiquitous has arrived, an infrastructure for the short-distance wireless communication has been extended socially, and thus a variety of services are being proposed. The Multimedia Contents Delivery System using the ZigBee, in particular, has an important stance in enlargement of a variety of services in the aspect of individual-oriented service support though Wireless Personal Area Network (WPAN). Nonetheless, the ZigBee, or the IEEE 802.15.4 Standard, has many restrictions on the Multimedia Contents Delivery System due to the low data transport rate. In order to improve the ZigBee which presents a limit on the transport rate at the IEEE 802.15.4 Standard, this thesis has designed the burst mode which is a method of transmitting a certain amount of data in block units at a high speed without any stoppage until the completion of the transmission. Also, to provide a Multimedia Contents Delivery Service with an application of the normal data transmission mode, it improved the transmission performance of the ZigBee. In addition, for the Multimedia Contents Delivery Service under the ubiquitous environment, it designed and implemented a broadcasting Multimedia Contents Delivery System based on the ZigBee to conduct a comparative analysis on the data transmission performance according to the transmission method.