Detection Technique of Fault Phenomena Using Power Parameters in Grinding Process

Kwak, Jae-Seob,Ha, Man-Kyung Korean Society for Precision Engineering 2002 International Journal of the Korean Society of Pre Vol.3 No.1

The grinding process has been mainly used fur finishing metal products as final machining stage. But chatter vibration and bum of a workpiece have a bad effect on the machined surface and should be detected in modern grinding process. This paper deals with a fault detection of the cylindrical plunge grinding process by power parameters. During the grinding process the power signals of an induced motor were sampled and used to determine the relationship between fault and change of power parameters. A neural network was used far detecting the grinding fault and an influence of power parameters to the grinding fault was analyzed.

Fault Detection of the Cylindrical Plunge Grinding Process by Using the Parameters of AE Signals

Kwak, Jae-Seob,Song, Ji-Bok The Korean Society of Mechanical Engineers 2000 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.14 No.7

The focus of this study is the development of a credible fault detection system of the cylindrical plunge grinding process. The acoustic emission (AE) signals generated during machining were analyzed to determine the relationship between grinding-related faults and characteristics of changes in signals. Furthermore, a neural network, which has excellent ability in pattern classification, was applied to the diagnosis system. The neural network was optimized with a momentum coefficient, a learning rate, and a structure of the hidden layer in the iterative learning process. The success rates of fault detection were verified.

Evaluation of Wheel Life by Grinding Ratio and Static Force

Kwak, Jae-Seob,Ha, Man-Kyung The Korean Society of Mechanical Engineers 2002 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.16 No.9

A degree of sharpness in wheel grains affects the surface roughness and dimensional accuracy in the grinding process. If a wheel with dull grains is used, the grinding force is increased and the surface roughness is deteriorated. In ovder to produce a precision component economically, the magnitude of the wear amount in the grinding wheel has to be limited. In this study, experimental evaluation of a wheel life varying with the grinding ratio and static grinding force was conducted. The grinding ratio and grinding force were measured to seek the grinding performance of the WA wheel. The relationship between the grinding ratio and static grinding force was presented.

Development of Lighting Compressed by Injection Yellow Ocher Soil

Kwak, Woo-Seob Korea Furniture Society 2008 한국가구학회지 Vol.19 No.6

The compressed injection yellow ocher soil is the process-technology by drying the product through sunshine, not by firing like pottery and ceramic ware. It is the technology of development being able to achieve the far infrared ray and humidity adjustment by adding recycling paper, Korean paper and bamboo salt, and it corresponds with the construction enforcement ordinance 2007 as an interior-finishing product which is fire-resistant. In case that the yellow ocher soil would be used as lighting device and interior-finishing material and decoration, it could contribute to an improvement of National Health by avoiding the sick house syndrome and adding humidity adjustment, and it has more efficient economic effect due to using recycle-available additives. Through such developments of the yellow ocher soil products the domestic market of lighting device and construction material can be advanced and the replacement effect of imported goods & also export effect can be expected accordingly.

A Study on the Fault Diagnosis Applied to the Grinding Power Signals

Kwak, Jae-Seob,Ha, Man-Kyung 韓國工作機械學會 2000 한국생산제조학회지 Vol.9 No.4

Undesired. trouble such as chatter vibration and burning on the ground surface appears frequently in the cylindrical plunge grinding process. Establishment of a credible fault diagnostic system for the grinding process is the major purpose of this study. Power signals generated during the grinding operation were sampled and analyzed to determine the relation-ship between grinding troubles and behavior of signal changes. In addition, a neural network that has an excellent ability for pattern classification was occupied for the trouble recognition. The neural network was optimized with a momentum coefficient, a- learning rate, and a structure of the hidden layer through the iterative learning process. Based on the estab-lished system, success rates of the trouble recognition were verified.

Force Modeling and Machining Characteristics of the Intermittent Grinding Wheels

Kwak, Jae-Seob,Ha, Man-Kyung The Korean Society of Mechanical Engineers 2001 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.15 No.3

In the surface grinding operations, the grinding fluid cannot be supplied sufficiently in the cutting zone. Temperature generated in the cutting zone increases rapidly and causes thermal damage such as burning on the surface of a workpiece. To reduce thermal damage, the intermittent grinding wheels, which have an excellent cooling effect, have been applied. This paper describes machining characteristics by using intermittent grinding wheels. The grinding force of the intermittent wheels has been simulated by the SIMULAB, which is a program for simulating dynamic systems. Using the intermittent grinding wheels, the characteristics of grinding force, temperature, surface roughness, and geometric error have been evaluated experimently.

Safety and Efficacy of Low-Volume Preparation in the Elderly: Oral Sulfate Solution on the Day before and Split-Dose Regimens (SEE SAFE) Study

Min Seob Kwak,Jae Myung Cha,Hyo-Joon Yang,Dong Il Park,Kyeong Ok Kim,Jun Lee,Jeong Eun Shin,Young Eun Joo,Jongha Park,Jeong-Sik Byeon,Hyun Gun Kim,Intestinal Cancer Study Group of the Korean Associati 거트앤리버 소화기연관학회협의회 2019 Gut and Liver Vol.13 No.2

Background/Aims: The use of a low-volume bowel cleansing agent is associated with a greater willingness to undergo repeat colonoscopy. Oral sulfate solution (OSS) is a recently approved low-volume agent; however, its efficacy and safety in the elderly population remain unclear. We aimed to evaluate the efficacy, safety, and acceptability of the OSS preparation, in comparison to those of a standard polyethylene glycol (PEG; 4 L) preparation, in elderly patients. Methods: A multicenter, randomized, investigator-blinded study was conducted. Participants were randomized to receive OSS or 4-L PEG with a split-dose regimen. Bowel cleansing efficacy was assessed using the Boston Bowel Preparation Scale (BBPS). Acceptance, satisfaction, and preparation-related symptoms were recorded. Additionally, blood parameters were analyzed for electrolyte abnormalities and nephrotoxicity. Results: A total of 193 patients were analyzed. No group differences in overall bowel cleansing efficacy were observed, with “adequate” preparations achieved in 95.9% (93/97) and 94.8% (91/96) of patients in the OSS and 4L PEG groups, respectively (p=0.747). However, mean BBPS scores for the entire (p=0.010) and right colon (p=0.001) were significantly higher in the OSS group than in the 4-L PEG group. The severity of clinical adverse events and frequency of acute kidney injury were similarly low, and no clinically meaningful electrolyte changes were identified. Self-reported scores regarding amount (p<0.001) and feeling (p=0.007), as well as overall satisfaction (p=0.001) and willingness to repeat the preparation (92.8% vs 67.7%, p<0.001), were significantly better in the OSS group than in the 4-L PEG group. Conclusions: In elderly individuals, OSS with a split-dose regimen has greater acceptability and comparable efficacy in bowel cleansing compared to 4-L PEG. (Clinical trials registration number: NCT03112967)

Application of Ultrasonic Technique for Extracting Crude Saponins from Liriope platyphylla (Maekmoondong)

In-Seob Kwak(곽인섭),Hyun-Jong Kim(김현종),Bong-Soo Lee(이봉수),Eun-Mi Lee(이은미),Hyun-Chul Lee(이현철),Bong-Woo Chung(정봉우) 한국생물공학회 2004 한국생물공학회 학술대회 Vol.2004 No.10

인터넷 쇼핑몰의 특성이 고객만족에 미치는 영향

곽원섭(Kwak Won-Seob) 한국문화산업학회 2004 문화산업연구 Vol.4 No.2

본 연구는 인터넷 쇼핑몰의 특성이 고객만족에 미치는 영향을 밝히고자 하였다. 이를 위해 대학생 568명을 대상으로 4개의 인터넷 쇼핑몰에 대한 과제 수행을 하도록 한후 방문 쇼핑몰에 대한 지각을 측정하였다. 그 결과 첫째, 인터넷 쇼핑몰의 특성을 측정하기 위한 문항들에 대한 요인분석 결과, 상품정보/전반적 구매절차 명확성, 시스템의 성능 및 안정성, 웹 사이트의 사용성, 보안 및 개인정보 보호, 디자인, 사업자정보의 명시성, 결제수단의 다양성 및 확인, 그리고 고객서비스의 8개 요인이 추출되었다. 둘째, 쇼핑몰의 특성 8개요인과 쇼핑몰에 대한 평판요인을 독립변수로, 쇼핑몰의 만족도 및 행동의도 각각을 종속변수로 한 회귀분석 결과, 3개의 종속변수 모두에서 공히 쇼핑몰 평판의 설명력이 가장 높았고, 쇼핑몰의 특성에서는 쇼핑몰 디자인, 쇼핑몰의 사용성, 보안 및 개인정보보호, 고객서비스 요인이 유의하게 나타났다. 이러한 결과를 기초로 쇼핑몰 운영에 있어서의 시사점을 논의하였다. The main objective of this study is to investigate the effects of factors of internet shopping malls on customer satisfaction in electronic commerce. It examines the following research questions: What dimensions are consisted of shopping mall site and what specific Web site cues are associated with customer satisfaction, and behavioral intention? We test our hypothesis in a empirical data from 568 consumers across 4 Web sites. By factor analysis, the results show that Web site characteristics are such as information of product and purchase process, system stability, navigation, privacy and security, design, information of seller, pay methods, and customer service. We also find that brand and Web site characteristics such as Web site design, navigation, privacy and security, and customer service can explain over 60% in satisfaction and 45% in behavioral intention. The results offer important implication for Web site strategies that include the manipulation of factors influencing customer satisfaction . And the future directions of the present research are discussed. 본 연구는 인터넷 쇼핑몰의 특성이 고객만족에 미치는 영향을 밝히고자 하였다. 이를 위해 대학생 568명을 대상으로 4개의 인터넷 쇼핑몰에 대한 과제 수행을 하도록 한후 방문 쇼핑몰에 대한 지각을 측정하였다. 그 결과 첫째, 인터넷 쇼핑몰의 특성을 측정하기 위한 문항들에 대한 요인분석 결과, 상품정보/전반적 구매절차 명확성, 시스템의 성능 및 안정성, 웹 사이트의 사용성, 보안 및 개인정보 보호, 디자인, 사업자정보의 명시성, 결제수단의 다양성 및 확인, 그리고 고객서비스의 8개 요인이 추출되었다. 둘째, 쇼핑몰의 특성 8개요인과 쇼핑몰에 대한 평판요인을 독립변수로, 쇼핑몰의 만족도 및 행동의도 각각을 종속변수로 한 회귀분석 결과, 3개의 종속변수 모두에서 공히 쇼핑몰 평판의 설명력이 가장 높았고, 쇼핑몰의 특성에서는 쇼핑몰 디자인, 쇼핑몰의 사용성, 보안 및 개인정보보호, 고객서비스 요인이 유의하게 나타났다. 이러한 결과를 기초로 쇼핑몰 운영에 있어서의 시사점을 논의하였다. The main objective of this study is to investigate the effects of factors of internet shopping malls on customer satisfaction in electronic commerce. It examines the following research questions: What dimensions are consisted of shopping mall site and what specific Web site cues are associated with customer satisfaction, and behavioral intention? We test our hypothesis in a empirical data from 568 consumers across 4 Web sites. By factor analysis, the results show that Web site characteristics are such as information of product and purchase process, system stability, navigation, privacy and security, design, information of seller, pay methods, and customer service. We also find that brand and Web site characteristics such as Web site design, navigation, privacy and security, and customer service can explain over 60% in satisfaction and 45% in behavioral intention. The results offer important implication for Web site strategies that include the manipulation of factors influencing customer satisfaction . And the future directions of the present research are discussed.

Force Modeling and Machining Characteristics of the Intermittent Grinding Wheels

Jae Seob Kwak,Man Kyung Ha 대한기계학회 2001 KSME International Journal Vol.15 No.3