• Journal of the Society of Naval Architects of Korea
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• v.42 no.1 s.139
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• pp.64-72
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• 2005

Digital manufacturing is a technology to simulate the real manufacturing process using the virtual model representing the physical schema and the behavior of the real manufacturing system including resources, processes and product information. Therefore, it can optimize the manufacturing system or prevent the bottleneck processes through the simulation before the manufacturing plan is executed. This study presents a method to apply the digital manufacturing technology for the steel cutting process in shipyard. The system modeling of cutting shop is carried out using the IDEF and UML which is a visual modeling language to document the artifacts of a complex system. Also, virtual NC simulators of the cutting machines are constructed to emulate the real operation of cutting machines and NC codes. The simulators are able to verify the cutting shape and estimate the precise cycle time of the planned NC codes. The validity of the virtual model is checked by comparing the real cutting time and shape with the simulated results. It is expected that the virtual NC simulators can be used for accurate estimation of the cutting time and shape in advance of real cutting work.

• Structural Engineering and Mechanics
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• v.66 no.3
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• pp.285-294
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• 2018

An experimental study has been carried out to analyze the effect of cutting parameters (cutting speed, feed and depth of cut) and tool nose radius on the surface roughness and the cutting force components during hard turning of the AISI 52100 (50 HRC) steel with a ceramic cutting tool. The tests have been conducted according to the methodology of planning experiments, based on an orthogonal plan of Taguchi (L27). By using the response surface methodology (RSM), the components of the cutting force and the roughness of the machined surface were modeled and the effects of the input parameters were analyzed statistically by ANOVA and RSM. The results show that the feed (f), the tool nose radius (r), the cutting speed (Vc), the interaction between feed and tool nose radius ($f{\times}r$) as well as that of the quadratic effect ($f^2$) all have significant effects on the surface roughness (Ra). The feed is the most influencing factor with a contribution of 47.31%. The components of the cutting force were strongly influenced by the depth of cut, followed by the advance with a lower degree. By comparing the experimental values with those predicted by the models of the cutting force components and the surface roughness, it appears that they are in very good correlation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1885-1888
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• 2003

As high technology industries such as IT and display have developed, demand for application parts of micro lens and lens array has been extremely increasing. According to these trends, many researchers are studying on the fabrication technology for parts of the micro lens by a variety of methods such as MEMS, Lithography, LIGA and so on. In this paper, we have performed researches related to ultra precision micro lens, lens array mold and fabrication of Lenticular lens mold for three-dimensional display by using mechanical micro end-milling and fly-cutting fabrication method. Tools used in this research were a diamond tool of R 150$\mu\textrm{m}$. Cutting conditions set up feed rate, spindle revolution. depth of cut and dwell time as variables. And we analyzed surface quality variation of the processed products according to the cutting conditions, and then carried out experiments to search the optimum conditions. Through this research, we have confirmed that we can fabricate the ultra precision micro lens mold with surface roughness Ra=20nm and the holographic lens mold by using micro end-milling and fly-cutting fabrication method. Furthermore, we demonstrated problems happened in the fabrication of the micro lens and established the foundation of experimental study for formulating its improvement plan.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1715-1724
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• 2015

This study assessed the long term structure of forest age groups and the possibility of a domestic wood supply based on the wood industry buildup master plan. Wood is assumed to be supplied by main cutting, renewal, cutting damaged trees and thinning. The cohort equation was applied to identify the dynamic changes in forest area according to the age groups. The sixth age group, which composed of only 7.7% in 2010, is expected to comprise 73% of the total production land. The area distributions of the other age groups are expected to be between 5.3 - 5.6%. Consequently, the production volume from main cutting accounts for approximately 93 - 95% of the total production. The production volume from thinning, which depends on the area of the second and third age groups, will be decreased gradually. When the volume of domestic timber supply was compared with the timber demand from a previous study, the self-sufficiency of timber demand will be approximately 83% in 2050.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.06a
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• pp.45-52
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• 2003

Construction and extension of road by industrialization are increasing. According to this, construction of large cutting slope is increasing. Therefore, many methods for slope stability by this are applied. Failure happens according to dip and dip direction of slope. It is actuality that is connoting unstable element. This slope include coaly shale. Stability of slope failure this study takes place by road extension running examination for stability property calculate. Use this and examined stability about stereographic projection and wedge failure. Apply suitable reinforcement countermeasure about unstable cutting slope and analyzed stability. Wish to consider effective and robust processing plan of great principle earth and sand side securing stability. Hereafter with these data, is going to utilize in reinforcement and failure prevention.

• Journal of the Korea Society of Computer and Information
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• v.14 no.4
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• pp.1-8
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• 2009

In this paper, we deal an implementation of the software that produces sub-optimal solution of cutting-ironbar planning problem using dynamic programming. Generally, it is required to design an optimization algorithm to accept the practical requirements of cutting ironbar manufacturing. But, this problem is a multiple-sized 1-dimensional cutting stock problem and Linear Programming approaches to get the optimal solution is difficult to be applied due to the problem of explosive computation and memory limitation. In order to overcome this problem, we reform the problem for applying Dynamic Programming and propose a cutting-ironbar planning algorithm searching the sub-optimal solution in the space of fixed amount of combinated columns by using heuristics. Then, we design a graphic user interfaces and screen displays to be operated conveniently in the industry workplace and implement the software using open-source GUI library toolkit, GTK+.

• Journal of the Korea Safety Management & Science
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• v.13 no.4
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• pp.213-223
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• 2011

Recent cross-country competition and Chinese steel industry because of the emerging steel industry in Korea is a very difficult situation. Therefore, the steel industry in order to overcome this difficult market environment, the quality, cost competitiveness, enhance customer service levels and enhance international competitiveness through is needed. In this study, the purpose of strengthening the competitiveness of steel companies in order and hit the recovery of raw materials have been developed to optimize the model, developed before and after the results were analyzed. In addition, when applied to other products in order to minimize risk and optimize cutting trial stage of development details of the model is presented in detail. Therefore, the developed model was applied to order the recovery of raw materials hits and significantly improved production planning time has been shortened dramatically. In the present study the contents of other products when properly applied and the competitiveness of companies to improve customer service levels are expected to be helpful.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.227-233
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• 2024

Korea achieved its highest ever defense export performance in 2022. Defense exports are the most effective way to promote the defense industry by exporting Korea's weapons to foreign countries. In addition, to continuously supply excellent weapon systems, a solid defense industry must be established. So defense industry exports are an important issue at the national level, the Korea government is actively supporting policies for the Presidential office as a control tower. In particular, the topic of entry into the defense industry export big4 is being raised in Korea. As an innovative defense export promotion plan, this paper presents a strategic plan of joint research and development that export customized to the needs of purchasing countries and securing cutting-edge technology that can possess world-class weapon systems. In other words, in order to secure cutting-edge technology, the military must break away from existing methods and boldly select cutting-edge technology, provide sufficient budget support, and grant autonomy to development agencies. A rapid acquisition system must also be introduced so that this technology can be applied to advanced weapons in a timely manner. Export joint research and development is intended to promote flexible technology transfer excluding ultra-sensitive core technologies and to form strategic partnerships, taking into account the purchasing country's willingness to possess cutting-edge technology. Through this, we have helped Korea's defense industry exports enter the world's big4 through groundbreaking new strategy.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.666-672
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• 2008

Train wheels are the most important part of the high-speed rail system with supporting body, running stably and safely. Wheel exchange and fix plan is computed by the worker who managing entire Train Maintenance Process based on his know-how so that this system is losing its reliability and accuracy. And predicting of the wheel's lifetime is absolutely difficult matter because of uncertainty between trains like mileage of the type of trains, condition of operation, curve section and wheel's cutting pattern. Therefore workers always used to hold many wheels. For this reason, the cost of stock is soar when the level of stock was normal. If the stock is sufficient, the cost of stock will rise. On the other hand, If the stock is deficient, we would have trouble that the plan of the train maintenance process will be failed. Thus this paper aimed at application that "Wheel Managing System" which is able to predict wheel's life-cycle and demands under the RIMS(Rolling-Stock Information Maintenance System) with analysing wheel exchanging and cutting status considering economical or stable aspects.

• Nuclear Engineering and Technology
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• v.54 no.9
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• pp.3242-3249
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• 2022

As Kori unit 1 is undergoing the decommissioning process, estimating the disposal amount of waste from the decommissioned nuclear reactor has become one of the challenging issues. Since the waste disposal amount estimation depends on the packing of the waste, it is highly desirable to optimize the waste packing plan. In this study, we developed an efficient scheme for packing waste component segments. The scheme consists of 1) preparing three-dimensional models of segments, 2) orienting each segment in such a way to minimize the bounding box volume, and 3) applying hybrid genetic algorithm to pack the segments in the disposal containers. When the packing solution converges in the algorithm, it comes up with the number of containers used and the placement of segments in each container. The scheme was applied to Kori-1 reactor pressure vessel. The required number of containers calculated by the developed scheme was 24 compared to 42 that was the estimation of the prior packing plan, resulting in disposal volume savings by more than 40%. The developed method is flexible for applications to various packing problems with waste segments from different cutting options and different sizes of containers.