• Journal of Environmental Health Sciences
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• v.3 no.1
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• pp.27-44
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• 1976

This study was carried out to evaluate the harmful factors in working environments and to investigate the labor productivity after improvement of environments, surveying 93 industrial establishments of 10 industries located in Youngdeungpo industrial area in Seoul. The results obtained were as follows: 1) The highest noise level of 125dB(A) was indicated at the rolling process of transport equipment manufacturing industry. 2) The best illumination level was shown in precise machinery industry and the worst was indicated in rubber products, metallic products and transport equipment manufacturing industries. 3) Thermal conditions were above threshold limit value (TLV) at more than two processes of all industries except printing industry. 4) The highest dust concentration was determined in textile and wearing manufacturing industry. 5) Organic solvents were detected at 52 processes in 93 industrial establishments and 33 processes of them showed higher than TLV. The results about harmful chemicals were as follows: a) sulfur dioxide ($SO_2$)was determined higher than TLV on welding process of metallic product manufacturing industry and heat treatment process of transport equipment manufacturing industry. b) Carbon monoxide (CO) concentration was 700ppm at heat treatment process of transport equipment manufacturing industry, indicating 14 times of TLV. c) vinylchloride concentration in the air of PVC raw material mixing process and PVC preparation process of chemical product manufacturing industry was determined higher than TLV. d) Hydrochloride (HCl) concentration in the air of wire expanding process of transport equipment manufacturing industry was determined higher than TLV. 7) Higher values of lead concentration than TLV were determined at lead welding metallic product manufacturing industry and type planting process of process of printing industry, $1.8mg/m^3$ and $0.3mg/m^3$ respectively. 9) 22, 968 of 52, 855 workers (i.e. 43.5%) in 93 industries were exposed to various harmful agents. 10) It was found that the improvement of illumination in electric apparatus manufacturing industry (from 20~40 lux to 420 lux) resulted in an increase in productivity of 6.5% per capita and a decrease in faulty products of 19%. 11) Improvement of environments using local exhaust ventilation system resulted in a decrease of harmful substances lower than TLV and an increase in productivity of 11.4%. 12) Improvement of shovelling tools based on ergonomics resulted in a reduction in energy expenditure of 25.3% and an increase in productivity of 32.2% per capita.

• International Journal of Automotive Technology
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• v.4 no.1
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• pp.47-55
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• 2003

The Center for Transportation Research at the Argonne National Laboratory (ANL) supports the DOE by evaluating advanced automotive technologies in a systems context. ha has developed a unique set of compatible simulation tools and test equipment to perform an integrated systems analysis project from modeling through hardware testing and validation. This project utilized these capabilities to demonstrate the trade-off in fuel economy and Oxides of Nitrogen (NOx) emissions in a so-called ‘pre-transmission’ parallel hybrid powertrain. The powertrain configuration (in simulation and on the dynamometer) consists of a Compression Ignition Direct Ignition (CIDI) engine, a Continuously Variable Transmission (CVT) and an electric drive motor coupled to the CVT input shaft. The trade-off is studied in a simulated environment using PSAT with different controllers (fuzzy logic and rule based) and engine models (neural network and steady state models developed from ANL data).

• Proceedings of the IEEK Conference
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• 2000.06b
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• pp.226-229
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• 2000

In this paper, we describe implementation of 32-Bit RISC Core for portable communication/information equipment, such as cellular telephones and personal digital assistants, notebook, etc. The RISC core implements the ARM$\^$R/V4 instruction set on the basis of low power techniques in architecture level and logic level. It operates with 5-stage pipeline, and has harvard architecture to increase execution speed. The processor is modeled and simulated in RTL level using VHDL. Behavioral Cache and MMU are added to the VHDL model for instruction level verification of the processor. The core is implemented using Mentor P'||'&'||'R tools with IDEC C-631 Cell library of 0.6$\mu\textrm{m}$ CMOS 1-poly 3-metal CMOS technology.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.909-912
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• 2005

According to miniaturization trend of rehabilitation medical equipment such as hearing aid, study to replace previous complex system with semiconductor SOC (System-on-Chip) chip becomes lively. In this study, after investigating of existent hearing aid performance in circuit design approach, low electric power consuming, single power supply (1.4V battery) CMOSS OP AMP was designed. Analog circuit design tools such as Hspice and Cadence were used for circuit simulation and implementing layout design. This study shows technical methods particularly for layout design. The work is done in pmos and nmos active element layout design in addition to passive element design such as resister, capacitor and inductor.

• Korean Journal of Computational Design and Engineering
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• v.21 no.1
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• pp.1-8
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• 2016

After 2017 years, BWMS units must be installed in the existing ship as well as the new ship by the ballast water management convention. Software tools that can help automatically searching for BWMS installation space to avoid pipes and equipment in the engine room of the existing ship will be very useful in the BWMS layout design. In this study, voxel representation of scanned data is generated first to search space efficiently. Simplified voxel models of each unit are prepared to be located in the engine room space as well. Distance between connected models is calculated through the arrangement direction and position of each model. Sums of distance between connected models are compared for the optimal configuration. It is assumed that the sum of distance between connected models depicts the pipe usage. The proposed method can save the time needed for BWMS installation design and allows optimal configuration of BWMS units.

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.119-121
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• 2003

The magnetic bearing is an important element for high-speed system, such as semiconductor equipment and machine tools. Particularly, The homopolar magnetic bearing has the advantages of lower power losses, more space for heat dissipation and coil winding. This paper deals with analysis and comparison of the homopolar magnetic bearing according to four different PM structures. On the basis of these results, we find one homopolar magnetic bearing superior to the others. finally, this paper derive force characteristic equation for this model and deals with comparison of between analytical and FE results.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.245-250
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• 2002

A successful on-line monitoring system for conventional machining operations has the potential to reduce cost, guarantee consistency of product quality, improve productivity and provide a safer environment for the operator. In fee-shape machining, typical signs of tool problems such as vibration, noise, chip flow characteristics and visual signs are almost unnoticeable without the use of special equipment. These characteristics increase the importance of automatic monitoring in fine-shape machining; however, sensing and interpretation of signals are more complex. In addition, the shafts of the micro-tools break before the typical extensive cutting edge of the tool gets damaged. In this study, the existence of a relationship between the characteristics of the cutting force and tool usage was investigated, and tool breakage detection algorithm was developed and the fellowing results are obtained. In data analysis, didn't use a relative error compare which mainly used in established experiment and investigated tool breakage detection algorithm in time domain which can detect AE and cutting force signals more effective and accurate.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.220-224
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• 2005

The technology trend of Flat Panel Display (FPD) equipments have been demanded that there are compact and multi-function. Therefore, nano/micro scale patterned on polymeric materials of Back Light Unit (BLU) in Liquid Crystal Display (LCD) that has been investigated. This paper describes a series of Horizontal Type Micro Tensile Tester that were carried out to investigate the load strain distance performance of typical polymeric material sheets. The polymeric materials film that micro size shaped specimens for tensile test are used by Cold-Isostatic-Press (CIP). Test equipment is Horizontal type Micro Tensile Tester that is presented to measure the micro scale mechanical property of thin film for FPD. This paper presents which easy testing tools measure for micro patterned on polyethylene (PET) specimens.

• Asian Journal of Innovation and Policy
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• v.3 no.2
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• pp.245-261
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• 2014

Knowledge, technology and information have special characteristics different from the ones of normal consumer products and services. Especially the value of such information varies according to external elements such as the provided environment, their method of utilization, and the level and purpose, etc. of the user. In this study, the indicators of information customer value are developed and measured to enhance customer-based values with efforts for making new customers and maintaining existing customers. The result is as follows: 14 customer value indicators were developed. Among the indicators, value gained versus effort, reduced time for research idea investigation and savings in time searching for equipment, and tools and materials got the highest score, which means that time-saving effects were the most important. The field study of this paper was conducted from information users in the field of national R&D, and thus future studies could be conducted in various industries in many countries to attain generalized results.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.5
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• pp.675-682
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• 2013

Reliability analysis and prediction of next failure time is critical to sustain weapon systems, concerning scheduled maintenance, spare parts replacement and maintenance interventions, etc. Since 1981, many methodology derived from various probabilistic and statistical theories has been suggested to do that activity. Nowadays, many A.I. tools have been used to support these predictions. Support Vector Regression(SVR) is a nonlinear regression technique extended from support vector machine. SVR can fit data flexibly and it has a wide variety of applications. This paper utilizes SVM and SVR with combining time series to predict the next failure time based on historical failure data. A numerical case using failure data from the military equipment is presented to demonstrate the performance of the proposed approach. Finally, the proposed approach is proved meaningful to predict next failure point and to estimate instantaneous failure rate and MTBF.