• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.03a
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• pp.41-46
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• 1996

In this study, unsintered and pre-sintered low purity alumina ceramics were machined with various tools to clarify the machinability, optimum tool materials and optimum cutting conditions. The main conclusions obtained were as follows. (1)In the case of dry cutting, the sintered diamond and natural diamond tools exhibit better performance in machining of the ceramic pre-sintered at lower temperature, and the tool lives of both tools in machining the ceramics pre-sintered at high temperature becomes extremely short. (2)The performance of CBN tool becomes better in dry machining of the ceramics pre-sintered at higher temperature. (3)When the pre-sintered ceramics were wet machined with sintered diamond, the tool life becomes considerably long, and higher cutting speed can be used than in the case of the CBN and ceramic tools, the tool lives becomes shorter at wet cutting than at dry cutting, especially exhibiting extremely short tool life in wet cutting with ceramic tool.

• Proceedings of the Korea Society for Simulation Conference
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• 1998.10a
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• pp.36-40
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• 1998

Tool shop of the‘D’Motor Co.(DMC) fabricates dies for producing automotive press panels. In order to increase the production capacity of the tool shop, DMC established an FMS that consists of high-speed machines and a CMM at the tool shop in 1997. Due to the difference in machine capability among the existing machines and the new FMS it is needed to find an optimal way of allocating workloads among machines to maximize the production. In a way to solve this, we model the die fabrication process of the tool shop and analyze its performance by computer simulation. In this study, we at first identify the bottleneck processes of the die fabrication process under the current operation policy. Then, we derive some alternative operating policies applicable to the tool shop, and analyze the optimal operation policy by comparing the performance of the tool shop following each alternative policy.

• Proceedings of the Korea Society for Simulation Conference
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• 1999.04a
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• pp.105-109
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• 1999

Tool shop of the D Heavy Industries Co.(DHI) fabricates engines for a bus, truck, small ship. In order to increase the production capacity of engines, DHI will be established the new tool shop that consists of a block line, head line, assembly line, test line and AS/RS in 1999. In order to assure the production capacity designed of the new tool shop for producing engines and improve the production process of it, it is needed to find a bottleneck process and an optimal way of allocating workloads among machines and workers to maximize the production. In a way to solve this, we model the engine fabrication process of the tool shop and analyze its performance by computer simulation. In this study, we at first identify the bottleneck processes of the engine fabrication process under the designed operation policy. Then, we derive some alternative operating policies applicable to the new tool shop of an engine, and analyze the optimal operation policy by comparing the performance of the tool shop following each alternative policy.

• Spatial Information Research
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• v.21 no.1
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• pp.53-62
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• 2013

The purpose of this study is to suggest the development direction of a BIM performance assessment tool. To do this, a series of focused group interviews were conducted with BIM experts in South Korea regarding the objective, characteristic, potential problems of a BIM performance assessment tool. A survey questionnaire was developed based on the focused group interviews and distributed to practitioners through four different occasions. The survey results showed that there were the significant differences between practitioners by their field and years of experience about the objective, characteristic, potential problems of a BIM performance assessment tool. Based on the survey results, the consideration factors for developing a BIM performance assessment tool was suggested.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.2
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• pp.228-236
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• 2002

In this study, the carbon steels, SM20C were machined with the tungsten carbide tipped circular saw to clarify the cutting-off characteristics in terms of tool wear. The results show that an improved performance in view of both the tool wear and the cutting efficiency was obtained by using oil base cutting fluid at the cutting speed of 100m/min with the feed of 0.06mm/tooth. The rake angle of 10$^{\circ}$ , clearance angle of 8$^{\circ}$ , nose radius of R0.1mm, and end cutting edge champer of 0.1mm$\times$25$^{\circ}$ are believed as the best tool geometries. The tool wear decreases due to using the saw of the disk of STS5 and the tool material of P30.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.354-361
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• 2005

In high speed cutting process, due to the friction between the tool and workpiece, a temperature rise of contacting part is serious. It need to develop cutting tool for overcoming such a poor condition. So now, some studies, the optimization of tool shapes, the fine grains of tool material, multi-layer coating of tools are processing. If mirror finishing on the tool is processed, there is advantage of relation between chip and tool, because of less friction, and also tool's lift would be increased. As a result mirror like finishing is expected efficient enhancement of tool. Generally, it is too difficult to process by a general way for tools of complex shapes, it is required a new method to process such complex shape tools. The magnetic fluid polishing technique can polish the workpiece of complex shape, because the polishing method which polishes as compress the workpiece by the magnetism abrasives to arrange to the linear according to the line of magnetic force. In this paper, We polished the surface of the high speed cutting tool using the magnetic fluid polishing technique, to enhance the performance of the high speed cutting tool.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.11
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• pp.2336-2341
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• 2002

When WC and group IV elements are added to Ti(C,N)-Ni cermet, microstructures of the cermet is changed. The change effects directly on the property of the material. In this study, the amount of WC and group IV elements of Ti(C,N) cermet tool was investigated. The composition of WC was changed from 5 to 20wt% to determine the effect of WC on the cutting performance of cermet tool. The more WC was added, the longer the tool life of the cermet tool was. The cermet with lwt% ZrC and l4wt% WC showed the best cutting performance among the investigated cermet tools. The cutting performance of cermet cutting tools suggests the possibility in interrupted cutting for reliability test experimentation was performed repeatedly with $Ti(C_{0.7},N_{0.3})- l4WC-1ZrC-20Ni$ cermet tool machining SCM440. The flank wear of cermet cutting tool at given time condition is suitable for Normal distribution and Log normal distribution by Chi squared test.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.59-65
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• 2003

Four kinds of $Si_3N_4$-based ceramic cutting tools with different sintering time were fabricated to investigante the effect of sintering time on the microstructure, mechanical properties, grain sizes and the cutting performance. An endeavor was also made to determine the relation among mechanical property, Brain size and tool life. $Si_3N_4$ home made cutting tool sintered for 1 hour under $1760^{\circ}$ temperature and 25MPa pressure showed the best cutting performance among selected ceramic tools during machining both Bray cast iron and heat treated SCM440. Multiple linear regression model was used to estimate the tool lift from mechanical property, grain size and showed good result. It was also shown that hardness imposed the biggest offect on tool life.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.215-216
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• 2019

The following conclusions were reached through the research on the development of the required performance extraction tools for the application and utilization of various construction methods of lightweght dry wall. 1) Performance required for walls of apartment buildings can be divided into safety, habitation, durability and productivity. Among these, horizontal load resistance, shock resistance, anti-seismic performance, insulation, and acoustic characteristics are the main performance that correspond to dry walls. In addition, safety related to toxic gases and contaminants are required according to recent eco-friendly requirements. 2) To select a wall according to the required performance of an inner wall applied to an apartment, a map tool in the form of 2D matrices was constructed to enable the required performance to be applied, indicating that the wall location and wall material and its differentiating according to the old method.

• Journal of Nutrition and Health
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• v.33 no.5
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• pp.548-555
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• 2000

The purpose of this study were to : a) establish quality managements standards and performance indicators in order to define the concept of the hospital food and nutrition services, b) develop a self evaluation tool for quality management applicable to dietetic department's CQI program on the basis of the estabilished quality management standers, c) investigate the factual quality of hospital food and nutrition services throught the result of the application study of the quality management tool and the perceived quality by the patients servery, and d) verify the validity of the quality management tool through analysing the correlation between the factual quality and the preceived quality. The quality management standards were classifie dinto 3 parts, 'Nutrition Care', 'Foodservice Operation', and 'Management Function'. There consisted of 72 quality management standards and 293 performance indicators. The developed quality evaluation tool using 5-Likert scale was performance at 45 general hospitals over 400 beds in Seoul and Kyungki-do. Also, 1,573 patients in 42 hospitals were participated in the patient survey. The result of quality evaluation tool application study showed that 17 standards were relatively high(more than 4.5) and 22 relatively low(less than 4.0) in score. The categorical mean scores of $\ulcorner$Nutrition Care$\lrcorner$, $\ulcorner$Foodservice Operation$\lrcorner$and $\ulcorner$Management Function$\lrcorner$ were respectively 60.7, 162.8, and 73.5 Each mean score was conversed to 81.0, 83.5, and 81.7 on the basis of 100 point scale, but the range of score was very wide between hospitals. The Cronbach's $\alpha$ was more than 0.6 in 59 quality management standards, this result verified reliability of the quality management tool was proved. The factual quality showed positive correlation with the perceived quality. Therefore, this result verified the criterion validity of the quality management tool.