• Journal of the Korean Society for Precision Engineering
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• v.25 no.4
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• pp.134-139
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• 2008

A spirally arrayed nano-pattern is designed as a model pattern for the next generation optical storage media. The pattern consists off types of embossed rectangular dot, which are 50nm, 100nm, 150nm and 200nm in length and 50nm in width. The height of the dot is designed to be 50nm. The pitch of the spiral track of the pattern is 100nm. A ER(Electron resist) master for this pattern is fabricated by e-beam lithography process. The ER is first spin-coated to be 50nm thick on a Si wafer and then the model pattern is written on the coated ER layer by e-beam. After developing this pattern written wafer in the solution, a ER pattern master is fabricated. The most conventional e-beam machine can write patterns in orthogonal way, so we made our own pattern generator which can write the pattern in circular or spiral way. This program generates the patterns to be compatible with the e-beam machine from Raith(Raith 150). To fabricate 50nm pattern master precisely, a series of experiments were done including the design compensation for the pattern size, optimization of the dose, acceleration voltage, aperture size and developing. Through these experiments, we conclude that the higher accelerating voltages and smaller aperture size are better for mastering the nano pattern which is in order of 50nm. With the optimized e-beam lithography process, a spiral arrayed 50nm pattern master adopting PMMA resist was fabricated to have dimensional accuracy over 95% compared to the designed. Using this pattern master, a metal pattern stamp will be fabricated by Ni electro plating for injection molding of the patterned plastic substrate.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.5
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• pp.26-37
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• 2009

This paper suggests a sensor's placement method for detecting the dilemma zone problem when real-time driver's safety service is provided at signalized intersections by multiple pointed traffic sensors using USN environments. For detecting the dangerous situations from vehicles accelerating through yellow intervals, red-light running and stopping abruptly like as dilemma zone problem, VISSIM(microscopic, behavior-based multi-purpose traffic simulation program) is used to perform a real-time multiple detection situation by changing the input data like as various inflow-volume, design speed change, driver perception and response time. As a result, the optimal interval of traffic sensors is 20~27m, and the initialized sensor location from stop-line is different according to road design speed. Moreover, the pattern of detection about dilemma zone is also different according to inflow-volumes. This paper shows that the method is useful to evaluate the sensor's placement problem based on micro-simulation and the results can be used as the basic research for USN services.

• Journal of the Korean Society for Railway
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• v.14 no.2
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• pp.167-173
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• 2011

This paper considers the problem of revising train departure time to reduce electric power consumption of mass rapid transit (MRT) railways. The motion of a train running between stations is divided into three phases: traction, coasting, and deceleration phases. The traction phase requires high electric power to operate MRT railways. In the coasting phase, the train moves stably by consuming little or no power. The deceleration phase is a braking mode and produces some electric power called regenerated brake power owing to inertia force for the train generated In the traction and coasting phases. The regenerative energy can be used by other accelerating trains within a specific range from the train and thereby the power consumptions of train can be reduced. We developed a mixed integer programming model to solve the problem. To validate the suggested model, a computational experiment was conducted using real data from Korea Metropolitan Subway.

• Journal of the Korean Institute of Landscape Architecture
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• v.13 no.1
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• pp.43-66
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• 1985

Korea needs proper and rational public policies on conservation and use of forest land and other natural resources because of the accelerating expansion of national land developments in recent years. Unfortunately, there is no systematic planning system to support the needs. Generally, forest land use planning needs suitability analysis based on efficient land classification system. The goal of this study was to classify a forest land using multivariate satistical methods. A case study was carried out in winter of 1983 on a mountainous area higher than 100m above sea level located at Mt. Kwanak in Anyang -city, Kyung-gi-do (province). The study area was 19.80 km$^2$wide and was divided into 1, 383 Operational Taxonomic Units (OTU's) by a 120m$\times$120m grid. Fourteen descriptors were identified and quantified for each OTU from existing national land data : elevation, slope, aspect, terrain form, geologic material, surface soil permeability, topsoil type, depth of the solum, soil acidity, forest cover type, stand size class, stand age class, stand density class, and simple forest soil capability class. For this study, a FORTRAN IV program was written for input and output map data, and the computer statistics packages, SPSS and BMD, were used to perform the multivariate statistical analysis. Fourteen variables were analyzed to investigate the characteristics of their fire quench distribution and to estimate the correlation coefficients among them. Principal component analysis was executed to find the dimensions of forest land characteristics, and factor scores were used for proper samples of OTU throughout the study area. In order to develop the classes of forest land classification based on 102 surrogates, cluster and discriminant analyses of principal descriptor variable matrix were undertaken. Results obtained through a series of multivariate statistical analyses were as follows ; 1) Principal component analysis was proved to be a useful tool for data selection and identification of principal descriptor variables which represented the characteristics of forest land and facilitated the selection of samples.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.8_spc
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• pp.1284-1295
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• 2019

Considerable progress in reproduction of dairy goats has been made, with advances in reproductive technology accelerating dairy goat production since the 1980s. Reproduction in goats is described as seasonal. The onset and length of the breeding season is dependent on various factors such as breed, climate, physiological stage, male effect, breeding system, and photoperiod. The reproductive physiology of goats was investigated extensively, including hypothalamic and pituitary control of the ovary related to estrus behavior and cyclicity etc. Photoperiodic treatments coupled with the male effect allow hormone-free synchronization of ovulation, but the kidding rate is still less than for hormonal treatments. Different protocols have been developed to meet the needs and expectations of producers; dairy industries are subject to growing demands for year round production. Hormonal treatments for synchronization of estrus and ovulation in combination with artificial insemination (AI) or natural mating facilitate out-of-season breeding and the grouping of the kidding period. The AI with fresh or frozen semen has been increasingly adopted in the intensive production system, this is perhaps the most powerful tool that reproductive physiologists and geneticists have provided the dairy goat industry with for improving reproductive efficiency, genetic progress and genetic materials transportation. One of the most exciting developments in the reproduction of dairy animals is embryo transfer (ET), the so-called second generation reproductive biotechnology following AI. Multiple ovulation and ET (MOET) program in dairy goats combining with estrus synchronization (ES) and AI significantly increase annual genetic improvement by decreasing the generation interval. Based on the advances in reproduction technologies that have been utilized through experiments and investigation, this review will focus on the application of these technologies and how they can be used to promote the dairy goat research and industry development in the future.

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.641-651
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• 2021

Supercomputers have played an important role in various fields such as science, industry, national security and solutions for social issues, and their demand is increasing significantly as their use is strengthened in areas using big data and AI. Recently, competition for global exascale system development is accelerating based on various architectures, and the era of exascale computing is expected to come in the near future. However, the foundation of the domestic supercomputing ecosystem was lost due to the decline of the server industry in the past, and although the related law was enacted to supplement and foster it, it has not been able to perform its function smoothly. Therefore, this article examines the problems in the current legal system through the analysis of the relevant legal system and the status of the supercomputing ecosystem, and suggests improvements so that the relevant legal system, which can accommodate the reinforcement of the role of the government·national center·professional center, support for industries, promotion of commercialization of research results, and flexibility of government promotion policies, can prepare the basis for the promotion of the supercomputing R&D project.

• Journal of The Korean Association of Information Education
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• v.26 no.1
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• pp.11-22
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• 2022

The educational environment, where the change to blended learning and AI convergence education through non-face-to-face is accelerating, is based on the cultivation of digital literacy. This study attempted to verify the effectiveness of future competencies by creating a collaborative SW education program on the metaverse platform that emerged by supplementing the problems through non-face-to-face. Twenty programs on how to design and create software were organized for small-scale elementary classes in the metaverse. In order to verify the effectiveness 4C competency tool presented as future educational competency was selected, and homogeneity test for the experimental group and t-test were conducted. The results showed the SW education programs based on metaverse was effective in improving collaborative communication skills, confirming the possibility of SW education through blended learning.

• Journal of Animal Science and Technology
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• v.64 no.3
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• pp.397-408
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• 2022

Rinse & Chill^® technology (RCT) entails rinsing the vasculature using a chilled isotonic solution (3℃; 98.5% water and a blend of dextrose, maltose, and sodium phosphates) to rinse out the residual blood from the carcass. Infusion of pre-chilled solutions into intact animal carcasses immediately upon exsanguination is advantageous in terms of lowering the internal muscle temperature and accelerating chilling. This technology is primarily used for purposes of effective blood removal, favorable pH decline, and efficient carcass chilling, all of which improve meat quality and safety. Although RCT solution contains some substrates, the pre-rigor muscle is still physiologically active at the time of early postmortem and vascular rinsing. Consequently, these substrates are fully metabolized by the muscle, leaving no detectable residues in meat. The technology has been commercially approved and in continuous use since 2000 in the United States and since 1997 in Australia. As of January 2022, 23 plants have implemented RCT among the 5 countries (Australia, US, Canada, New Zealand, and Japan) that have evaluated and approved RCT. All plants are operating under sound Sanitation Standard Operation Procedures (SSOP) and a sound Hazard Analysis Critical Control Point (HACCP) program. No food safety issues have been reported associated with the use of this technology. RCT has been adapted by the meat industry to improve product safety and meat quality while improving economic performance. Therefore, this review summarizes highlights of how RCT technically works on a variety of animal types (beef, bison, pork, and lamb).

• Journal of Korea Entertainment Industry Association
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• v.13 no.4
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• pp.149-155
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• 2019

In order to let the world know a real China, China has been strengthening the cultural pursuit of radio and TV programs and accelerating the development of cultural TV programs. By developing cultural TV programs, we can maintain the characteristics of national culture, publicize Chinese traditional culture and introduce the time-honored Chinese civilization to the world. Television can not only keep people informed of current events and social issues, but also provide people with colorful cultural life and entertainment. It is an innovation to spread cultural programs by means of entertainment. TV programs convey relevant cultural contents to the audience through various forms so as to improve the audience's cultural literacy and social influence. This paper summarizes the development background and current situation of Chinese TV culture, and gives some thoughts on the development of current cultural programs, which can provide some references for the communication and development of Chinese cultural TV programs.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.6
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• pp.424-432
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• 2023

This study deals with the design of a safety device around a leisure boat propeller. The safety device is to be designed to minimize performance degradation attached to propulsors in coastal waters. These devices, important for preventing propeller accidents, negatively gives influence boat performance, especially at higher speeds. In order to minimize the negative effect, the accelerating ducts, normally used in ESDs (Energy Saving Devices) have been chosen as a safety device. The present study aims to design an optimal duct (minimizing negative effect) through the parametric study. Based on the Marine 19A nozzle, the nozzle's thickness and angle were varied to obtain the optimum parameter in the preliminary design by the computational fluid dynamics program Star-CCM+ Ver. 15.02. In the detailed design, a NACA 4-digit Airfoil shape resembling the Marine 19A by modification at the trailing edge was chosen and the optimum shape was chosen according to variation of camber, thickness, and incidence angle for optimization. The optimally designed duct shows a speed decrease of about 10% in the sea trial result, which is much smaller than the normal speed decrease of at least 30%. The present designing method can give wide applications to the leisure boat because the wake is almost the same due to using the outboard propulsor.