HDD 공기 베어링 슬라이더의 트랙 탐색 동특성

정태건 건국대학교 산업기술연구원 1998 건국기술연구논문지 Vol.23 No.-

Recently almost all HDDs employ the rotary type actuator system. The performance of an HDD depends on the accuracy and speed of tracking motion. The overall stiffness of the actuator system is confined by the flexibility of the flexure that is necessary to maintain the safe slider air bearing condition. This determines the upper bound of the bandwidth of the tracking servo system. We study the track seek process through the structural analysis for the actuator system considering the head/media interface. We develop the numerical analysis program to study the dynamic characteristics considering the air bearing effects. We perform the track seek simulation to estimate the effect of the suspension vibration on the air bearing status. We calculate the behaviour of the air bearing for the given tracking acceleration profile and calculate the error during track seek process due to the lateral deflection of the suspension.

압전변압기를 이용한 LCD Backlight용 구동회로의 개발

강태구,안형근,한득영 건국대학교 산업기술연구원 1998 건국기술연구논문지 Vol.23 No.-

This paper describes a driving circuit with a multi-layered piezoelectric transformer(MPT) for the LCD backlight of a portable computer. In order to develop the circuit, we measured at first the L, C, R of the MPT concerned. And, using the measured parameters of L,C,R, we designed and implemented circuits such as a voltage-frequency converter, comparator for tracking resonance frequencies varying when the backlight is turned on, power circuit with two MOSFETs, and triggering circuit with flip/flops. We showed the possibility of tracking the resonance frequency of the MPT under the various load conditions.

AO Synthes 금속판을 이용한 전방 경추 유합술후 발생한 지연성 식도 천공

송하헌,김태균,심대무 圓光大學校 醫科學硏究所 1999 圓光醫科學 Vol.15 No.1

Esophageal perforation after anterior cervical discectomy operation has a rare incidence. Also Delayed Esophageal perforation after anterior cervical discectomy has a very rare incidence. Esophageal perforaton is usually characterized as being due to the surgical exposure, metallic implant, bone graft, fractured vertebrae and polymethylmethacrylate. Esophageal perforaton result in fatal mediastinitis, which may lead to die from sepsis. The mortality rate continues to be more than 20%. Factors that adversely affect the outcome include the location and severity of the esophageal injury] associated injuries and delayed diagnosis and treatment. The purpose of this report is to present the our case of a patient who had delayed esophageal perforation by irritation of metallic screw and 3 weeks post operatively, and to know how can we get a early diagnosis and treatment in delayed esophageal perforation.

An Approach to BMI Problems Using Genetic Algorithm

Tac-Jin Chung,Chan-Soo Chung 제어로봇시스템학회 2000 제어로봇시스템학회 합동학술대회 논문집 Vol.2000 No.3

Transactivation of Fibronectin Promoter by HTLV - 1 Tax through NF - κB Pathway

(Tac Ghee Yi),(Byung Heon Lee),(Rang Woon Park),(In San Kim) 경북대학교 유전공학연구소 2000 遺傳工學硏究所報 Vol.14 No.-

Preclinical examination of transplantation of human melanocytes and adipose-derived stromal cells for the treatment of vitiligo

Jin Tac Kim,Sueng Yeun Kang,Ji Hyang Kim,Ai-young Lee,Byung-Rok Do 한국발생생물학회 2013 한국발생생물학회 학술발표대회 Vol.2013 No.8

Human mesenchymal stem cells are known that multipotent stromal cells have the ability to divide asymmetrically, differentiate into many tissue types, and modulate cellular fate or function. Previous reports have proved that direct or indirect effects of mesenchymal stem cells in damaged cells or tissue were able to contribute to regenerative remodeling. One of incurable diseases, vitiligo is a depigmenting skin disorder resulting from the loss of melanocytes in the epidermis. Although vitiligo is a common disorder with a frequency of 0.1~2% in population, it still remains incurable and recurrent. Up to now, various treatment methods has been available for vitiligo therapy. Especially, transplantation of melanocytes (MCs) cultured with keratinocytes (KCs) is well-known therapy in clinic. We have recently reported functional role of adipose-derived stromal cells (ASCs) could assist MCs growth and maintenance of immature MCs. Therefore, the present study investigated whether the influence of ASCs may be elevated a transplantation yield of MCs in vivo. Transplantation was accomplished by syringe injection or grafting after dermabrasion. The procedure of dermabrasion is a mechanically invasive skin planning method and may be to help settle adequate location of transplanted cells to therapy. To improve an efficacy of cell transplantation, various additives or conditions of ratio were compared in vivo. These data was concluded that mixture of MCs and ASCs in the determined condition was improved engraftments of melanocytes for patients with vitiligo.

Replicative senescence of periodontal fibroblasts induces the changes in gene expression pattern

Yi, Tac Ghee,Jun, JI-Hae,Min, Byung-Moo,Kim, Moonkyu,Kim, Gwan-shik,Baek, Jeong-Hwa 대한구강생물학회 2007 International Journal of Oral Biology Vol.32 No.1

Tooth loss in elderly is mainly caused by alveolar bone loss via severe periodontitis. Although the severity of periodontitis is known to be affected by age, the aging process or the genetic changes during the aging of periodontal tissue cells are not well characterized. In this study, we investigated the effect of in vitro aging on the change of gene expression pattern in periodontal fibroblasts. Gingival fibroblasts (GF) and periodontal ligament fibroblasts (PDL) were obtained from two young patients and replicative senescence was induced by sequential subcultivation. When more than 90% cells were positively stained with senescence-associated β-galactosidase, those cells were regarded as aged cells. In aged GF and PDL, the level of phosphorylated retinoblastoma (RB) and p16^(INK4A) protein was significantly decreased and increased, respectively. However, the protein level of p53 and p21, well known senescence-inducing genes, did not increase in aged GF and PDL. Although p27^(kip1) and p15^(INK4B) another cyclin-dependent kinase inhibitors, were reported to be involved in replicative senescence of human cells, they were decreased in aged GF and PDL. Because senescent cells showed flattened and enlarged cell shape and are known to have increased focal adhesion, we examined the protein level of several integrins. Aged GF and PDL showed increased protein level of integrin α2, αv, and β1. When the gene expression profiles of actively proliferating young cells and aged cells were compared by cDNA microarray of 3,063 genes and were confirmed by reverse transcription polymerase chain reaction, 7 genes and 15 genes were significantly and commonly increased and decreased, respectively, in aged GF and PDL. Among them, included are the genes that were known to be involved in the regulation of cell cycle, gene transcription, or integrin signaling. The change of gene expression pattern in GF and PDL was minimally similar to that of oral keratinocyte. These results suggest that p16^(INK4A)/RB might be involved in replicative senescence of periodontal fibroblasts and the change of gene expression profile during aging process is cell type specific.

가맹점의 러닝로열티 지불의도에 영향을 주는 서비스품질요인의 우선순위 연구

권태우 ( Tac Woo Kwon ),최강화 ( Kang Hwa Choi ) 한국경영공학회 2011 한국경영공학회지 Vol.16 No.1

This research is to improve the operational framework for Korean franchise business in food service by investigate the cause and effect relationships with those factors which have been provided the service from franchisor to franchisee. Although the franchise industry grows in Korea rapidly, the stability of business is still in doubt because business cycle of franchisor is get shortened. In this paper would find out the reason why the franchisor have the unstable status in Korea. The main reason was the instability of profit structures for franchisor which would be burden the franchisees that worsen the franchisor financial status. Comparing with the US franchise system, the biggest different was the running royalty program. So, this paper would prove how the running royalty program would help the franchisor to be the stable status with the continuous payment from the franchisees, and also show the how this payment would returned with better service to the franchisees. Throughout this study, It would examinate the franchisee`s intentions of running royalty payments since there is no running royalty cases in Korean franchise industry in food service. it would investigate willingness of running royalty payments with those five service quality factors which provided from the franchisor. It would analyze the hierarchy by its priorities among those SERVQUAL factors, which would affect to the intentions of running royalty payments by using AHP analysis.

Cryopreservation of human adipose tissue derived mesenchymal stem cells and primary epidermal melanocytes for vitiligo therapy

Jin-Tac KIM,Byoeng Kyu KIM,Seung Hoon PARK,Chan Do PARK,Ji Hyang KIM,Yong-Dal YOON,Ai-Young LEE,Byung-Rok DO 한국생물공학회 2010 한국생물공학회 학술대회 Vol.2010 No.4

인터넷 스포츠 사이트 이용에 따른 만족도 분석 연구

김태윤 ( Tac Yoon Kim ),홍명보 ( Myung Bo Hong ),이진경 ( Jin Kyung Lee ) 고려대학교 스포츠과학연구소 2009 스포츠科學論叢 Vol.15 No.-

본 연구는 인터넷 스포츠 관련 사이트 이용자를 대상으로 스포츠 정보 이용실태에 따른 만족도를 조사하여 이용자 욕구에 맞는 체계적이고 실용적인 자료를 제공하여 인터넷을 이용한 스포츠 마케팅 전략에 효율적 방안을 제시 하는데 목적이 있다. 이를 위해 스포츠 정보 관련 사이트를 접해 본 20대 대학생을 편의표본추출방법(convenience sampling)으로 추출하여 321명의 자료를 분석에 사용하였다 수집된 자료는 spss 12.0 프로그램을 이용하여 탐색적 요인분석, 신뢰도 분석, 빈도분석, 교차분석, 일원분산분석(one-way ANOVA), 다중회귀분석(multiple regression analysis)을 실시하였고, 다음과 같은 결과를 얻었다. 스포츠 정보 이용자의 성별, 주 이용 빈도, 하루 이용시간에 따른 만족도에는 유의미한 차이가 있는 것으로 나타났다. 스포츠 정보 이용자의 신뢰성, 신속성, 디자인, 서비스 순으로 만족요인이 높을 때 향후 이용가능성도 높아지는 것으로 나타났다. This study was aimed to find out the most effective sports marketing strategies especially focused on using the Internet by providing systematic and practical data to be used for satisfying the needs of the users who receive sports related services on the websites. i this study, subjects consist of students from University in their 20s who were chosen by convenience sampling. With the collected 321 data, multiple regression analysis, one-way ANOV A and cross tabulation analysis, descriptive analysis were performed by SPSS version 12.0 program. The results of this research were as follows; First, in case of using traits, they showed significantly differences in sex, average number of visit a week, time a day. Secondly, the users`` satisfaction was indicated to have effect on reliability, agility, design, service factors in order.