• Journal of Environmental Health Sciences
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• v.18 no.2
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• pp.67-74
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• 1992

The lab-scale biological A$_{2}$O system was applied from treating piggery wastewater highly polluted organic material which nitrogen and phosphorous are much contained relatively in conversion with other wastewater. The objective of this study was to investigate the effect of variance parameters on the treatability of this system according to operation conditions. An obtained experimental data were analysed by using principal component analysis (PCA) method. The results are summarized as follows: 1. From Varimax rotated factor loading in raw wastewater, variance of factor 1 was 36.8% and cumulative percentage of variance from factor 1 to factor 4 was 81.5% and of these was related to BOD, TKN and BOD loading. 2. In anaerobic process, variance of factor 1 was 33.5% and cumulative percentage of variance from factor I to factor 4 was 81.8% and of these was related to PO$_{4}$-P, BOD, DO and Temperature. 3. In anoxic process, variance of factor 1 was 30.1% and cumulative percentage of variance from factor i to factor 4 was 84.3% and of these was related to pH, DO, TKN and temperature. 4. In aerobic process, variance of factor 1 was 43.8% and cumulative percentage of variance from factor 1 to factor 4 was 81.5% and of these was highly related to DO, PO$_{4}$-P and BOD. 5. It was better to be operated below 0.30 kg/kg$\cdot$day F/M ratio to keep over 90% of BOD and SS, 80% of TKN, and 60% of PO$_{4}$-P in treatment efficiencies. 6. Treatment efficiencies was over 93% of BOD and SS, 81% of TKN and 60% of PO$_{4}$-P at over 20$^{\circ}$C, respectively.

• Journal of the Korea Safety Management & Science
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• v.11 no.4
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• pp.237-246
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• 2009

In this paper, we propose development of new products including the proposed process of at the customer's requirements. The success of new product development depends on customer satisfaction in the marketplace. Existing product development process, including the customer's interest was weak. In this paper, we propose development of new products which include Kano's attractive quality factor method and Timko's customer satisfaction index method. Also we verified new medical treatment of incontinence-nency which is applied to the proposed process.

• 한국벤처창업학회:학술대회논문집
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• 2009.10a
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• pp.31-47
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• 2009

In this paper, we propose development of new products including the proposed process of at the customer's requirements. The success of new product development depends on customer satisfaction in the marketplace. Existing product development process, including the customer's interest was weak. In this paper, we propose development of new products which include Kano's attractive quality factor method and Timko's customer satisfaction index method. Also we verified new medical treatment of incontinence-nency which is applied to the proposed process.

• Proceedings of the Safety Management and Science Conference
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• 2009.11a
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• pp.83-97
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• 2009

In this paper, we propose development of new products including the proposed process of at the customer's requirements. The success of new product development depends on customer satisfaction in the marketplace. Existing product development process, including the customer's interest was weak. In this paper, we propose development of new products which include Kano's attractive quality factor method and Timko's customer satisfaction index method. Also we verified new medical treatment of incontinence-nency which is applied to the proposed process.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.6
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• pp.837-848
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• 2006

This paper presents the test results of biological aerated filtration(BAF) process to replace activated sludge process by enhancing treated effluent quality and reducing the costs. In BAF process both BOD and SS compounds in wastewater are degraded and removed by biological reaction and filtration. Upflow BAF with expanded polypropylene media and downflow BAF with ceramic media were used to investigate the effects of hydraulic and organic loads on effluent quality. As a result, in BAF processes which has different media, upflow BAF reactor shows 5% higher efficiency than downflow BAF and this phenomena caused by backwashing methods and operational conditions. The results of influence factors analyzed by Factor Analysis Method in BOD and SS treatment efficiency are the size of media, hight of media bed and type of media. The quantitative effects of media size are 5.73% in TBOD, 5.78% in SBOD and 7.65% in TSS, so we confirmed the main factor is media size.

• Current Photovoltaic Research
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• v.6 no.1
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• pp.27-30
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• 2018

The dependency of the electrical characteristics of silicon solar-cells on the depth of damaged layer induced by wire-sawing process was investigated. To compare cell efficiency with residual sawing damage, silicon solar-cells were fabricated by using as-sawn wafers having different depth of saw damage without any damaged etching process. The damaged layer induced by wire-sawing process in silicon bulk intensely influenced the value of fill factor on solar cells, degrading fill factor to 57.20%. In addition, the photovoltaic characteristics of solar cells applying texturing process shows that although the initial depth of saw-damage induced by wire-sawing process was different, the value of short-circuit current, fill-factor, and power-conversion-efficiency have an almost same, showing ~17.4% of cell efficiency. It indicated that the degradation of solar-cell efficiency induced by wire-sawing process could be prevented by eliminating all damaged layer through sufficient pyramid-surface texturing process.

• Journal of the Korea Safety Management & Science
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• v.15 no.1
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• pp.293-301
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• 2013

The purpose of this study is to introduce the limit of previously used six sigma quality process evaluation metrics, $Z_{st}$ and $P_{pk}$, and a solution to overcome this drawback by using a metric based on performance evaluation of Z-factor quality innovation. Case analysis on projects from national six sigma contest from 2011 to 2012 is performed and literature review on new drug development HTS (High Throughput Screening) is used to propose innovative performance evaluation metrics. This research shows that experimental study on six sigma evaluation metric, $Z_{st}$ and $P_{pk}$, have no significance difference between industrial type (Manufacturing, Semi-Public Institute, Public Institute) and CTQ type (Product Technology Type CTQ, Process Technology Type CTQ). Following discovery characterize this quality improvement as fixed target type project. As newly developed moving target type of quality innovation performance metric Z-Factor is used for evaluating experimental study, hypothetical analysis suggests that $Z_{st}$ and $P_{pk}$ share different relationship or even show reciprocal relationship. Constraints of the study are relatively small sample size of only 37 projects from past 2 years and conflict on having interview and communication with six sigma quality practitioner for qualitative experimental study. Both moving target type six sigma innovation project and fixed target type improvement project or quality circle enables efficient ways for a better understanding and quality practitioner use by applying quality innovation performance metric. Downside of fixed target type quality performance evaluation metric, $Z_{st}$ and $P_{pk}$, is presented through experimental study. In contrast, advantage of this study is that high throughput requiring product technology, process technology and quantum leap typed innovation effect is evaluated based on precision and accuracy and Z-Factor that enables relative comparison between enterprises is proposed and implemented.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.3
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• pp.85-89
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• 2013

In the current domestic, many industrial accidents have happened. And these are analyzed according to several factors. But it is difficult that they evaluate their business safety. Thus, we conducted a study on business specific safety assessment techniques in order that business know their safety level and perform appropriative safety activities. Study methods are survey and AHP (Analytic Hierarchy Process). Each specific weighting factors to calculate the survey was conducted for safety and consulting experts (20 persons). Weight factor was used to AHP decision support as one of the ways through a number of alternatives to the ratings for the Minesota Multiphasic. Factors are each type of industry, specific industrial scale, disaster type and strength, worker age and tenure period, and region. First, survey was conducted with 20 professionals to estimate the weighting factors. Weights between factors using the AHP analysis tool based on the mean values were calculated. Second, last 3 years between the industrial accidents statistics were used to calculate the weights for each of the rating factors in the Occupational Safety and Health Agency. Grade weights between each factor which was based on the rating of each factor was calculated as the average of three years. Finally, the weights between each factor and the grade weights for each factor using the safety level of the enterprise were calculated so that you can evaluate the weighting.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.8
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• pp.534-541
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• 2014

This study investigated a method to determine an efficient operating condition for the $UV/H_2O_2$ process. The OH radical scavenging factor is the most important factor to predict the removal efficiency of the target compound and determine the operating condition of the $UV/H_2O_2$ process. To rapidly and simply measure the scavenging factor, Rhodamine B (RhB) was selected as a probe compound. Its reliability was verified by comparing it with a typical probe compound (para-chlorobenzoic acid, pCBA); the difference between RhB and pCBA was only 1.1%. In a prediction test for the removal of Ibuprofen, the RhB method also shows a high reliability with an error rate of about 5% between the experimental result and the model prediction using the measured scavenging factor. In the monitoring result, the scavenging factor in the influent water of the $UV/H_2O_2$ pilot plant was changed up to 200% for about 8 months, suggesting that the required UV dose could be increased about 1.7 times to achieve 90% caffeine removal. These results show the importance of the scavenging factor measurement in the $UV/H_2O_2$ process, and the operating condition could simply be determined from the scavenging factor, absorbance, and information pertaining to the target compound.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.4
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• pp.144-150
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• 2005

Gas-assisted injection molding (GAIM) process is reducing the injection pressure during mold filling required as well as the shrinkage and warpage of the part and cycle time. Despite of these advantages, this process introduces new parameters and makes the application more difficult because the process interacts between gas and melt during injection molding process. Important GAIM factors that involved in this process include gas penetration design, locations of gas injection points, shot size, gas injection delay time as well as common injection molding parameters, gas pressure and gas injection time. In this study, the experiments were conducted to investigate effects of GAIM process variables on the gas penetration for PP and ABS moldings by changing gas injection point. Taguchi method was used fer the design of experiment. When the gas was injected at cavity's center, the most effective factor was shot size. When the gas was injected at cavity's end, the most effective factor was melt temperature. Injection speed was also an effective factor in GAIM process.