• Journal of Computational Design and Engineering
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• v.1 no.3
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• pp.194-201
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• 2014

Optimization of design is an important step in obtaining tissue engineering scaffolds with appropriate shapes and inner micro-structures. Different shapes and sizes of scaffolds are modeled using UGS NX 6.0 software with variable pore sizes. The quality issue we are concerned is the scaffold porosity, which is mainly caused by the fabrication inaccuracies. Bone scaffolds are usually characterized using a scanning electron microscope, but this study presents a new automated inspection and classification technique. Due to many numbers and size variations for the pores, the manual inspection of the fabricated scaffolds tends to be error-prone and costly. Manual inspection also raises the chance of contamination. Thus, non-contact, precise inspection is preferred. In this study, the critical dimensions are automatically measured by the vision camera. The measured data are analyzed to classify the quality characteristics. The automated inspection and classification techniques developed in this study are expected to improve the quality of the fabricated scaffolds and reduce the overall cost of manufacturing.

• Journal of Sensor Science and Technology
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• v.21 no.4
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• pp.249-255
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• 2012

Among the human senses, olfactory information still does not have a proper data presentation method unlike that regarding vision and auditory information. It makes presenting the sense of smell into multimedia information impossible, which may be an exploratory field in human computer interaction. In this paper, we propose an olfactory information presentation method, which is a way to use smell as multimedia information, and show an application for scent generation and odor display using a web service. The olfactory information can present smell characteristics such as intensity, persistence, hedonic tone, and odor description. The structure of data format based on olfactory information can also be organized according to data types such as integer, float, char, string, and bitmap. Furthermore, it can be used for data transmitting via a web service and for odor display using a scent generator. The scent generator, which can display information of smell, is developed to generate 6 odors using 6 aroma solutions and a diluted solution with 14 micro-valves and a micropump. Throughout the experiment, we confirm that the remote user can grasp information of smell transmitted by messenger service and request odor display to the computer controlled scent generator. It contributes to enlarge existing virtual reality and to be proposed as a standard reference method regarding olfactory information presentation for future multimedia technology.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.461-466
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• 2007

There has been a great interest in printing technology as a low cost and mass production method for the application of printed electronics such as printed TFT, solar cell, RFID Tag, printed battery, and so on. In this study, apparatuses of gravure-offset printing are developed for fine line-width/gap printing and examining pattern distortion occurred in gravure-offset printing process. The fine line-width/gap pattern shows that it is possible to make around 20 micro-meter line-width/gap printing patterns. Pattern distortion is modeled, and the amount and shape of the distortion are calculated by using commercial FEM code. The roll-to-roll printing system under development consists of unwinder/rewinder, two printing units, one coating unit, drying units, guiding unit, vision system, and other auxiliary devices. For multi-layer printing, the system is designed to be capable of printing two different materials.

• Journal of the Korean Solar Energy Society
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• v.32 no.5
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• pp.94-101
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• 2012

A Dokdo wind resource map has been drawn up for the Green Island Energy Master Plan according to Korea's national vision for 'Low Carbon Green Growth'. The micro-siting software WindSim v5.1,which is based on Computational Flow Analysis, is used with MERRA reanalysis data as synoptic climatology input data, and sensitivity analysis on turbulence model is accompanied. A wind resource assessment has been conducted for the Dokdo wind power dissemination plan, which consists of two 10kW wind turbines to be installed at the Dongdo dock and Dokdo guard building. It is evaluated that the capacity factors at Dongdo dock and Dokdo guard building are about 20% and 30% respectively, and annual and hourly variations of wind power generation have been analyzed, but summertime energy production is predicted to be only 40% of wintertime energy production.

• Journal of the Korean Vacuum Society
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• v.17 no.6
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• pp.501-510
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• 2008

The stealth technology to conceal an aircraft from the vision of a radar have been accomplished by coating the surface with special paints absorbing the electromagnetic wave. Nowadays, researches to utilize characteristics of the plasma-wave interaction for realizing the stealth technology are actively progressed. In this paper, to investigate the physical feasibility of the plasma stealth, calculation results for the required conditions of the plasma cloaking on the aircraft flying in the air for showing the stealth function, using a flat non-magnetized non-uniform plasma model, are reported and discussed.

• Journal of Korea Society of Waste Management
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• v.35 no.8
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• pp.683-691
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• 2018

The plastic strategy adopted by the EU in January 2018 was established to implement circular economic policies and the Sustainable Development Goals(SDGs) of the United Nations. The strategy includes the vision and implementation measures to achieve, which are primarily measures to improve recycling and increase demand for recycled plastics. The representative measures include the design that considers recycling possibilities, reinforcement of demand for recycled plastics, suppression of occurrence, and response to micro-plastics. The policies to implement these measures include legislative restrictions and economic measures (EPR, GPP). It is especially desirable that the policies are applied differently depending on the plastic product. The Korean government has established comprehensive measures for all stages from production to recycling, but those measures are not comprehensive compared to the EU's strategy. The reason is that the refusal of waste collection makes the Korean government establish the approach from the aspect of waste management instead of the implementation of a circular economy or SDGs like the EU. The countermeasures are aimed at achieving a 50% reduction in waste generation amount and a 70% recycling rate. It is considered that the possibility of achieving the goal will increase by examining the measures and policy means in the EU's plastics strategy.

• Computers and Concrete
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• v.32 no.5
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• pp.475-486
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• 2023

Nondestructive evaluation (NDE) is an important task of civil engineering structure monitoring and inspection, but minor damage such as small cracks in local structure is difficult to observe. If cracks continued expansion may cause partial or even overall damage to the structure. Therefore, monitoring and detecting the structure in the early stage of crack propagation is important. The crack detection technology based on machine vision has been widely studied, but there are still some problems such as bad recognition effect for small cracks. In this paper, we proposed a deep learning method based on sweep signals to evaluate concrete surface crack with a width less than 1 mm. Two convolutional neural networks (CNNs) are used to analyze the one-dimensional (1D) frequency sweep signal and the two-dimensional (2D) time-frequency image, respectively, and the probability value of average damage (ADPV) is proposed to evaluate the minor damage of structural. Finally, we use the standard deviation of energy ratio change (ERVSD) and infrared thermography (IRT) to compare with ADPV to verify the effectiveness of the method proposed in this paper. The experiment results show that the method proposed in this paper can effectively predict whether the concrete surface is damaged and the severity of damage.

• The Korean Journal of Vision Science
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• v.20 no.4
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• pp.553-560
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• 2018

Purpose : To investigate a disposal method of disposing contact lenses and the recognition of environmental pollution by micro plastics which may be caused by the wrong disposal method of domestic contact lens wearers. Methods : Two hundred sixty one adults(124 males, 137 females, mean age $21.48{\pm}3.14years$) were participated in this study. They were given the questionnaire survey on contact lenses purchasing place, type of contact lenses, duration of wearing contact lenses, the disposal method of disposing contact lenses and the recognition of the occurrence of environmental pollution. Results : It appeared that eyeglass shop(50.0%) and contact lens shop(48.3%) were the main purchasing places, and the most common type of contact lenses were disposable lenses(38.5%) and daily wearing lenses(52.5%). On the duration of wearing contact lenses they answered more than 5 years(29.3%), less than 1 year (26.0%), less than 1 year to less than 3 years (26.0%), and on wearing a contact lens during a week they did 1-2 days (32.0%), 1 week (28.0%), 5-6 days (22.4%) and 3-4 days (17.6%). It was shown "no(78.3%)" and "yes(21.7%)" to the questionnaire of whether they received information or education about a disposal method at the place where the contact lens was purchased, and "no(87.5%)" and "yes(12.5%)" to the questionnaire of whether they received information or education from schools, public institutions or public media such as the internet. As for the disposal methods, landfill waste(45.6%), recycled garbage(29.6%), and drainage(16.8%) from the sink or toilet responded in order. Although men were more educated and informed about disposal than women (t=3.63189, p<0.00001), women were more aware of environmental pollution(t=2.44269, p=0.01605). Conclusion : In order to reduce the environmental pollution issue caused by the contact lens which does not decompose at the sewage treatment facility and become micro plastics, it is urgent to provide information about correct disposal methods after using contact lenses and to educate contact lens wearers.

• Tunnel and Underground Space
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• v.29 no.4
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• pp.230-242
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• 2019

While various automatic rock fracture survey methods have been researched, the evaluation of the accuracy of these methods raises issues due to the absence of a metric which fully expresses the similarity between automatic and manual fracture maps. Therefore, this paper proposes a geometry similarity metric which is especially designed to determine the overall similarity of fracture maps and to evaluate the accuracy of rock fracture survey methods by a single number. The proposed metric, Scanline Intersection Similarity (SIS), is derived by conducting a large number of scanline surveys upon two fracture maps using Python code. By comparing the frequency of intersections over a large number of scanlines, SIS is able to express the overall similarity between two fracture maps. The proposed metric was compared with Intersection Over Union (IoU) which is a widely used evaluation metric in computer vision. Results showed that IoU is inappropriate for evaluating the geometry similarity of fracture maps because it is overly sensitive to minor geometry differences of thin elongated objects. The proposed metric, on the other hand, reflected macro-geometry differences rather than micro-geometry differences, showing good agreement with human perception. The metric was further applied to evaluate the accuracy of a deep learning-based automatic fracture surveying method which resulted as 0.674 (SIS). However, the proposed metric is currently limited to 2D fracture maps and requires comparison with rock joint parameters such as RQD.

• The Journal of Fisheries Business Administration
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• v.15 no.1
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• pp.1-57
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• 1984

The fisherman has been playing the roles of forming the fisheries village and surviving the fisheries production. Therefore, we should understand the nature of the fisherman's successor-cultivation which has been performed in order to maintain equlibrium between the fisheries economy and the national economy. Thesedays, fisherman's successor-cultivation mainly has been undertaken by the government in order to facilitate forming the economic foundation of fisherman's successor who has intended to choose "fisheries" as his own occupation in the future. From the above-mentioned, we find the meaning of the undertaking as both securing the foundation of living permanently and having the worth-while life of a professional fisherman by the survival and growth of his own business. And then, choosing the "fisheries" as an occupation, the successor should be satisfied with the requisites of occupation: 1) maintaining one's living, 2) working out one's individuality, 3) fulfilling one's social role-through engaging in the fisheries. Therefore, in order to have these requisites satisfied, I intend to suggest the followings : Firstly to maintain one's living, the environment of fisheies village should be kept in good condition to facilitate the successor's economic performance. Secondly to work out one's individuality, the fisheries' educational system should be adjusted to improve fisherman's ability. 1 hope to institute "the course of regional fisheries management" in fisheries high school and junior vocational collage, and "the school of fisheries management" for the learning of advanced fisheries knowledge. Thirdly to fulfill one's role, the opportunity actively participating in decision-making of the village's affair should be prepared more sufficiently, and the present fishing-centered fisheries system should be reformed into the fish-farming-centered fisheries system. To do this, the long-perspective vision is necessary. These three suggestions are come out from the macro-view point. Meanwhile the fisherman as an individual to improve his business is from the micro-view point. That is, the public aid, financial and legal, should be prepared. The above-mentioned suggestions are necessary to equalize fisherman's social status with other professional's especially from the result of improving the successor's economic force. Therefore, the principle of cultivating the fisherman's successor should be the principle of social equilibrium. be the principle of social equilibrium.