• Journal of Korea Port Economic Association
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• v.25 no.3
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• pp.165-182
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• 2009

The purpose of this paper is to study on the third party logistics service enforcement of inland container depot at Pusan area. The main results of this paper are as follows: First, the inland container depot related to location selecting factor researches analyzed and korean TPL market reviewed. Second, the TPL service function reinforcement method and investments are mentioned. In detail the 9 factors are as follows: competitive high position and improvements of harbor back complex, ICD goods enterprise investment strategies, the harbor back which is inexpensive only the rent, taxes benefit and incentive, site security and base facility expansion, the goods service provision which is flexible, connection plan construction of goods enterprise, the incentive strategic establishment which is discriminated, the marketing activity which is long-term. and lastly the ICD and TPL Policy are needed that government and logistic enterprise's cooperation gains competitive advantage.

• Korean Journal of Optics and Photonics
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• v.28 no.5
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• pp.213-220
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• 2017

This paper proposes how to fabricate an educational Mach-Zehnder interferometer that is easy to align and inexpensive, using 3D printers and semiconductor lasers. The interferometer consists of a body $165mm{\times}120mm{\times}57mm$ in size, mirror mounts, a laser holder, beam splitters, and so on. The laser path is adjusted by 4 mirror mounts, each comprised of rubber bands, small metal wires, and a screw. The interference fringe is enlarged by the lens at the final stage. The refractive index of a slide glass was measured by counting the number of moving interference fringes while the slide glass, inserted into one of the two interferometer arms, is rotating. The formula for the refractive index as a function of the optical-path difference and rotation angle was obtained, and used to calculate the refractive index of glass from the interferometer experiment. The use of a rotating glass in one arm of the interferometer nullifies the need for a precision stage, which despite its high cost is often required to observe the moving interference fringe in the classroom. Therefore, the 3D-printed Mach-Zehnder interferometer proposed in this paper can be very useful for education, because of its affordability and performance. It enables students to perform both qualitative and quantitative studies using a 3D-printed interferometer, such as measuring the refractive index of a glass sample, and the wavelength of light.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.32.1-32.4
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• 2020

Background: Le Fort I osteotomy is a highly effective treatment for skeletal jaw deformities and is commonly performed. High Le Fort I osteotomy is a modified surgical procedure performed for improving the depression of the cheeks by setting the osteotomy higher than the conventional Le Fort I osteotomy. Developments in three-dimensional (3D) technology have popularized the use of 3D printers in various institutions, especially in orthognathic surgeries. In this study, we report a safe and inexpensive method of performing a high Le Fort I osteotomy using a novel 3D device and piezosurgery, which prevent tooth root injury without disturbing the operation field for patients with a short midface and long tooth roots. Results: A 17-year-old woman presented with facial asymmetry, mandibular protrusion, a short midface, and long tooth roots. We planned high Le Fort I osteotomy and bilateral sagittal split ramus osteotomy. Prevention of damage to the roots of the teeth and the infraorbital nerve and accurate determination of the posterior osteotomy line were crucial for clinical success. Le Fort I osteotomy using 3D devices has been reported previously but were particularly large in size for this case. Additionally, setting the fixing screw of the device was difficult, because of the risk of damage to the roots of the teeth. Therefore, a different surgical technique, other than the conventional Le Fort I osteotomy and 3D device, was required. The left and right parts of the 3D device were fabricated separately, to prevent any interference in the surgical field. Further, the 3D device was designed to accurately cover the bone surface from the piriform aperture to the infra-zygomatic crest with two fixation points (the anterior nasal spine and the piriform aperture), which ensured stabilization of the 3D device. The device is thin and does not interfere with the surgical field. Safe and accurate surgical performance is possible using this device and piezosurgery. The roots of the teeth and the infraorbital nerve were unharmed during the surgery. Conclusions: This device is considerably smaller than conventional devices and is a simple, low-cost, and efficient method for performing accurate high Le Fort I osteotomy.

• Journal of Adhesion and Interface
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• v.22 no.1
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• pp.1-7
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• 2021

The importance of high capacity energy storage devices has recently emerged for stable power supply through renewable energy generation. From this point of view, the Na-air battery (NAB), which is a next-generation secondary battery, is receiving huge attention because it can realize a high capacity through abundant and inexpensive raw materials. In this study, activated carbon-based catalysts for hybrid type Na-air batteries were prepared and their characteristics were compared and analysed. In particular, from the viewpoint of resource recycling, activated carbon (Orange-C) was prepared using discarded orange peel, and performance was compared with Vulcan carbon, which is widely used. In addition, a Pt/C catalyst (homemade-Pt/C, HM-Pt/C) was synthesized using a modified polyol method to check whether the prepared activated carbon can be used as a supported catalyst, and a commercial Pt/C catalyst (Commercial Pt/C) and electrochemical performance were compared. The prepared Orange-C exhibited a typical H3 type BET isotherm, which is evidence that micropore and mesopore exist. In addition, in the case of HM-Pt/C, it was confirmed through TEM analysis that Pt particles were evenly distributed on the activated carbon supported catalyst. In particular, the HM-Pt/C-based NAB showed the smallest voltage gap (0.224V) and good voltage efficiency (92.34%) in the 1st galvanostatic charge-discharge test. In addition, the cycle performance test conducted for 20 cycles showed the most stable performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.8-17
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• 2018

A large urban region in Bangkok, Thailand is often inundated due to shallow water floods along the paved roads that have poor drainage facilities, and that can cause urban flooding. Existing methods, including using sand bags are not effective to prevent flooding in urban areas where the amount of sand is not sufficient. Thus, it is necessary to install artificial flood defense structures. However flooding and overflow defense equipment, which was developed in some advanced nations in Europe and in the USA, is highly expensive and complex construction methods are needed, therefore they are not suitable to be used in Southeast Asia. Thus, it is necessary to develop a flood rapid defense system(FRDS), which is inexpensive and simple to build, but is also highly functional. Thus, this study developed an FRDS that can be applied to Southeast Asia through the careful study of FRDS overviews, an analysis on the development trends in Korea and overseas, and the proposal of development needs and directions of the region. For the system developed, Korean Standards(KS) performance evaluations on leakage ratio deformation tests and impact resistance tests were conducted at the Outdoor Demonstration Test Center(Seosan) in the Korea Conformity Laboratories(KCL) and the system satisfied the standards of KS F 2639(leakage and deformation test) and KS F 2236(impact resistance test). The present study results can not only be applied to urban floods in Southeast Asian nations to cope with flood-related disasters, but also be utilized in flood prone regions and for major facilities in Korea. They can also induce scientific and pro-active responses from major local governments and facility management organizations in relation to urban floods.

• Journal of The Korean Association of Information Education
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• v.23 no.1
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• pp.73-84
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• 2019

Maker movement is emerging as one of the key areas of the fourth industrial revolution in recent years. The maker movement is to create and share what users need using a variety of inexpensive production tools such as open source software and hardware, 3D printers and laser cutters. We think that the effect would be enhanced if design thinking is applied to elementary and middle school (K-12) class. The purpose of this study is to develop a design thinking-based maker education program and to apply it to classroom for clarify the effect on the creative problem solving ability of elementary school students. In order to verify the purpose of the research, students in the 5th-6th grades of elementary school were divided into a controlled group and an experimental group. The general lecture maker class was applied in the controlled group, and our developed design thinking-based maker class was simultaneously applied in the experimental group. The creative problem solving ability test was conducted before and after the test, and its effectiveness was verified using statistical t-test. In conclusion, this study suggests that design thinking-based maker education program has a positive effect on elementary school students' creative problem solving ability.

• Korean Journal of Ornithology
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• v.25 no.2
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• pp.69-76
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• 2018

Sexual dimorphism in birds refers to male-female differences in body size, plumage, color and/or behavior. In general, many seabirds, including the family of Laridae, are monomorphic in plumage-color, which makes the determination of sex difficult in the field because both parents also tend to share a great portion of parental care. The development of an inexpensive sexing tool facilitates understanding the degree of sex-specific parental care in the evolution of the life history. Here, we developed a non-invasive method for the determination of sex using the bill-head morphometric of known captive pairs and applied this tool to wild pairs to document factors underlying male-female parental care during the incubation period of Saunders's gulls (Saundersilarus saundersi). Males exhibited relatively larger bill-head ratios than their mates within naturally formed pairs in captivity, resulting in the determination of sex in12 wild pairs at the nest during the incubation period. Males and females equally shared the incubation role during the daytime, attending the nest at a high rate of 95%. However, the male's proportion of nest attentiveness greatly increased with time towards sunset, presumably reflecting the male duty for nighttime incubation. The present study provides a non-invasive method for the determination of sex in a monomorphic seagull species and highlights how male-female incubation behavior is associated with time of the day, rather than other ecological conditions.

• Journal of Digital Convergence
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• v.19 no.5
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• pp.145-152
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• 2021

In this study, we have examined the effect of open innovation of SMEs on innovation performance of firms. Most studies do not consider internal generation in relation to open innovation and innovation performance.We conducted empirical studies to overcome this problem. The research was carried out by collecting data collected from 512 SMEs and the 3SLS method was used to minimize the internal generation. As a result, open innovation investment and use of external ideas among SMEs' open innovation have positively influenced project success and technical performance. But, the introduction of technology and cooperation with the research organization did not affect the innovation performance, which is presumed to be due to the fact that the open innovation of SMEs is limited to relatively inexpensive activities. Therefore, in order to promote open innovation of SMEs, it is necessary to provide support for relatively high-cost activities and to improve the innovation performance of enterprises. In order to reduce the difficulties of open innovation activities, domestic universities and research institutes should support the construction of enterprise networks and actively support the utilization of technology to expand innovation performance.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.311-321
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• 2019

Greenhouse farmers often use thermal screens to reduce greenhouse heating expenses during the winter, and for shade during hot, sunny days in the summer, as it is an inexpensive solution to temperature control relative to other available options. However, accurate measurements of their emitted and absorbed radiations are important for the selection of suitable screens that offer maximum performance. Material's ability to save energy is highly dependent on these properties. Limited studies have investigated the measurement of these properties under natural conditions, but they are only applicable to materials having partial porosities. In this work, we describe a new radiation balance method for determining emissive power and absorptive capacity, as well as reflectivity, transmissivity and emissivity of materials having complete and partial transparency by using pyrgeometer and net radiometer. In this study, four materials with zero porosity, were tested. The emissivity value of PE, LD-13, LD-15 and PH-20 was $0.439{\pm}0.020$, $0.460{\pm}0.010$, $0.454{\pm}0.004$, and $0.499{\pm}0.006$, respectively. All tested samples showed high emitted radiation as compared to absorbed radiation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.763-769
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• 2021

In this study, ionic liquids were synthesized to remove carbon dioxide (CO2) on a laboratory scale. The vapor-liquid absorption equilibrium device (VLE) was used to investigate the carbon dioxide absorption capacity. In the regeneration study, the absorption capacity after regeneration was reduced by approximately 7% for all ionic liquids, in which the anion was sulfite-based, showing excellent regeneration. Ethyl sulfite showed the highest absorption capacity of CO2 among the ionic liquids based on the sulfite anion. In particular, the absorption capacity of [beim] ethyl sulfite was 1.1 mol CO2 / mol IL at an absorption equilibrium pressure of 22 bar. In the regeneration study, the absorption capacity after regeneration was reduced by approximately 7% for all ionic liquids, in which the anion was sulfite-based, from which regeneration is outstanding. After the absorption experiment, the viscosity of the sample tended to decrease by approximately 8% compared to that before the absorption experiment. On the other hand, the absorbent was synthesized in the first step. Moreover, the raw material used is also inexpensive and has excellent reproducibility and highly stable absorbent capacity.