• Nuclear Engineering and Technology
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• 제42권4호
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• pp.442-449
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• 2010

Recently, the neutron irradiation for large diameter silicon (Si)-ingots of more than 8" diameter is requested to satisfy the demand for the neutron transmutation doping silicon (NTD-Si). By increasing the Si-ingot diameter, the radial non-uniformity becomes larger due to the neutron attenuation effect, which results in a limit of the feasible diameter of the Si-ingot. The current evaluation method has a certain limit to precisely evaluate the radial uniformity of Si-ingot because the current evaluation method does not consider the effect of the Si-ingot diameter on the radial uniformity. The objective of this study is to propose a new evaluation method of radial uniformity by improving the conventional evaluation approach. To precisely predict the radial uniformity of a Si-ingot with large diameter, numerical verification is conducted through comparison with the measured data and introducing the new evaluation method. A new concept of a gradient is introduced as an alternative approach of radial uniformity evaluation instead of the radial resistivity gradient (RRG) interpretation. Using the new concept of gradient, the normalized reaction rate gradient (NRG) and the surface normalized reaction rate gradient (SNRG) are described. By introducing NRG, the radial uniformity can be evaluated with one certain standard regardless of the ingot diameter and irradiation condition. Furthermore, by introducing SNRG, the uniformity on the Si-ingot surface, which is ignored by RRG and NRG, can be evaluated successfully. Finally, the radial uniformity flattening methods are installed by the stainless steel thermal neutron filter and additional Si-pipe to reduce SNRG.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1806-1808
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• 1999

The electrical and physical characteristics of MgO and Pt thin-films on Si substrate, deposited by r.f magnetron sputtering. It were analyzed with annealing condition($1000^{\circ}C$ for 120 min) by four point probe, a-step, SEM and XRD. Until $1000^{\circ}C$ of annealing temperature, MgO medium layer had the properties of improving Pt adhesion to $SiO_2$ and insulation without chemical reaction to Pt thin-films and the resistivity of Pt thin-films was improved. In the analysis of properties of Pt-RTD, TCR value had $3927ppm/^{\circ}C$ and liner in the temperature range of room temperature ${\sim}400^{\circ}C$.

• 한국생산제조학회지
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• 제22권5호
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• pp.795-799
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• 2013

This paper describes a novel hybrid surface polishing process combining non-traditional electrochemical polishing (ECP) with external artificial ultrasonic vibration. The purpose of this study is to develop an easier method for improving stainless steel surfaces. To this end, vibration electrochemical polishing (VECP), a novel ultrasonic manufacturing process, for enhancing electrochemical reaction and surface quality compared with that achieved using conventional ECP is suggested. In addition, for finding the optimized experimental conditions, the two methods are compared under various current densities. Localized roughness of the work material is measured with atomic force microscopy (AFM) and scanning electron microscopy (SEM) for obtaining detailed surface information.

• 대한인간공학회지
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• 제19권2호
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• pp.1-14
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• 2000

Driving simulators have been developed for evaluating users' reaction to various driving situations. Dynamic simulators have, however, limitations of the motion feedback in space. Therefore, this paper presents a driving simulator and suggests a human sensibility ergonomics (kansei engineering) method to be used in improving sense of motion through a vehicle simulator. Human sensibility ergonomics(kansei engineering) is defined as translating technology of the customer' feeling about a new product into design elements. Constituents of the simulator were defined and the virtual world was generated by the object modeling technique. Senses perceived were classified into feelings of velocity, acceleration, rotation, and vibration based on the human sensibility associated with driving. And the most frequent verbal expressions were collected from 17 male subjects to define complex human sensibility.

• 한국세라믹학회지
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• 제53권4호
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• pp.429-434
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• 2016

Here, we introduce a means of utilizing waste oyster shells which were obtained from temporary storage near coastal workplaces as $CO_2$ adsorbents. The calcined CaO can be easily dissociated to $Ca^{2+}$ cation and $CO_3{^{2-}}$ anion by hydrolysis and gas-liquid carbonation reaction and converted to precipitated calcium carbonate (PCC) in algae-containing water. The calcium hydroxide and carbonation combination in algae-containing water significantly contributed to improving water quality which is very dependent on the addition amount of calcined powders.

• Membrane and Water Treatment
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• 제11권3호
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• pp.173-177
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• 2020

Wastewater treatment plants (WWTPs) have been recognized as one of the significant greenhouse gas (GHG) generators, due to the complex biochemical reaction and huge consumption of energy and materials. Recently, WWTPs have been built underground and they will be confronted with the challenges of mitigating GHG emissions and improving the quality of treated wastewater. Here, we focus on estimating GHG emissions to set up effective management plans for a WWTP built underground. First, we apply the process-based life cycle assessment (LCA) with an inventory database of the underground WWTP for a case study. Then, we identify significant factors affecting GHG emissions during service life using sensitivity analysis and suggest the proper tactics that could properly reduce GHG emissions from the WWTP.

• 대한기계학회논문집B
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• 제28권3호
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• pp.281-288
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• 2004

Combustion using oxygen enriched air is an energy saving technology that can increase thermal efficiency by improving the burning rate and by increasing the flame temperature. Flame figures, OH radical intensities, temperature distributions and emissions concentration were examined according to oxygen enriched concentration(OEC) in a turbulent diffusion flat flame. As long as the oxygen enriched concentration was increased, the length and volume of the flat flame was decreased while OH radical intensity was raised and the flame temperature was increased. However, RMS of the fluctuating temperature was decreased, and more homogeneous temperature field was formed. Thermal NO also was increased with increase of oxygen enriched concentration, but CO was decreased due to the increase of chemical reaction rate.

• 산업경영시스템학회지
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• 제20권42호
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• pp.193-200
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• 1997

For the industrialized nations, the manufacturing industries have becomes increasingly difficult to meet customers' demands and complete on the international market. Thus, manufacturing industries must be able tn react quickly to prevailing market conditions and to maximize the utilization of resources. Within recent years, computer technology, in conjunction with software technology, has made available to the manufacturer tools which can greatly improve their reaction to a new market situation, speeding up the design of products, improving process planning, maximizing resource scheduling, and streamling production flow through factories. This paper investigate "CALS" systems for motor's companies. The purpose of this study is to give some ideas of finding a better way of constructing "CALS" system in Korea motor's companies.a motor's companies.

• 보건교육건강증진학회지
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• 제18권3호
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• pp.177-186
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• 2001

The purpose of this study was to investigate the of regular worksite health exercise program participation on related fitness. Subject for study were 34 middle-aged women in Kwangju-city. To achieve this, body composition, cardiopulmonary function, physical fitness of every subjects were measured before and post regular health exercise program participation during 12 week. The results of this study were as follows: 1. Regular health exercise program participation result from improving the body composition, but there is not significant different statistically(p〈.05). 2. Significant differences were observed in the cardiopulmonary function(vital capacity, VO$_2$ max) after regular exercise program during 12 week(p〈.05). 3. Significant differences were observed in the flexibility(sitting trunk flexion), abdominal endurance(sit-ups), power (standing high jump), agility(trunk reaction time) after regular exercise program during 12 week(p〈.05).

• 펄프종이기술
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• 제35권5호
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• pp.1-9
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• 2003

Effectiveness of the microparticle retention systems in improving drainage, retention, formation has been recognized for many years. In this study the effectiveness of crosslinked cationic corn starches and silica-based microgels as components of Compozil system has been evaluated. It was shown that improvements in retention and strength could be achieved by employing crosslinked cationic corn starches especially at high conductivity. Silica-based microgels with better performance in retention and drainage than a commercial colloidal silica sol have been made through a reaction of sulfuric acid and sodium silicate solutions.