Sliding Mode Stabilization of a Centrifugal Compress or with Spool Dynamics

Chau-Chung Song,Song-Shyong Chen,Der-Cherng Liaw 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

In this paper, the topic of robust stabilization of a centrifugal compress or with spool dynamics is studied and presented. Sliding mode controls for systems with matching-type and mismatching-type uncertainties are seperately designed and verified. The sliding mode design is chosen to achieve the stability of the working equili brium for systems without uncertainties. However, it is known that uncertainties in the spool dynamics and the compress or characteristic are most likely to happen in the real applications. By actuating only the throttle as the single control input, the robust stabilization of the working equili brium is proposed by using as liding mode control. Numerical simulations are given to demonstrate the feasibility of the proposed and derived approaches.

Construction of a Wireless Sensor Networking Platform with Vibration Sensing and GPS Positioning

Chau-Chung Song,Yin-Chieh Hsu,Chen-Fu Feng,Yu-Kai Chen 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

In this paper, the networking architectures and information middleware of wireless sensor networks are developed to construct the heterogeneous information system platform for the real-time structural health monitoring application. The design and implementation of sensor firmware and networking middleware are the key study topics for WSN-based intelligent system platform. The networking gateway of system platform must be developed the independent and highly interoperability to integrate the heterogeneous networks. The application study combined with vibration sensing and GPS positioning is used to demonstrate the feasibility of the developed system platform. The middleware technology is implemented to filter and pre-process the received data from the Zigbee sensor node and extract the available information to transfer to and record in the system database. Moreover, the GPRS and GSM modules are used to be responsible for the long-distance and alarm message transmission on the information network, respectively. Furthermore, the integration system platform is constructed by integrating Zigbee sensor network, GPRS/GSM communication and LAN internet to illustrate and evaluate the feasibility and performance of the proposed architecture for wireless sensor systems. In conclusion, the intelligent system platform of WSN-based monitoring system is developed and integrated to demonstrate and speed up the practical applications of wireless sensor networks in this paper.

한국관광지 매력속성에 따른 베트남인 패키지관광객의 만족도 및 행동의도에 관한 연구

이엔(Chau, Ngoc Yen),정기은(Chung, Gi Eun) 한국문화산업학회 2016 문화산업연구 Vol.16 No.4

본 연구의 목적은 한국 방문 베트남 패키지 관광객을 대상으로 관광지 매력속성별 만족도와 전반적 관광만족도 및 행동의도간의 관계를 살펴보 고 동시에 관광행태에 따른 집단별 관광지 매력속성별 만족도와 전반적 관광만족도 및 행동의도간의 차이를 분석하는 것이다. 본 연구의 분석결과 통계적으로 한국관광지 매력속성별 만족도 7개 요인 중 ‘편의성’, ‘환대·쾌적성’, ‘관광지의 고유성’, ‘지역특색’ 등 4개 요인만이 전반적 관광만족도에 유의한 영향을 미친 것으로 분석되었는데, 이러한 4개 요인의 만족도 제고를 위하여 다음과 같은 시사점을 제시하고자 한다. 첫째, ‘편의성’에 대한 만족도를 더욱 높이기 위해서는 ‘기후’ 항목에 대한 만족도를 향상시키는 방안을 고려할 수 있다. 이를 위해 베트남의 기 후조건을 역이용한 다채로운 겨울계절 상품의 개발을 제안한다. 둘째, ‘환대·쾌적성’ 요인의 경우, 방한 베트남 관광객들의 평가에 따르면 한국관광지의 종업원 서비스에 불만이 많은 것으로 조사되었다. 따라서, 현장접점에 있는 직원들에게 베트남 문화 및 역사에 대한 교육의 실시를 제안한다. 셋째, ‘관광지의 고유성’ 요인의 경우 ‘자연․경관의 아름다움’에 대한 베트남관광객의 만족도는 가장 낮았는데, 이의 개선을 위해서 한국의 아름다운 자연자원과 베트남인들이 선호하는 한류콘텐츠를 효과적으로 융합한 상품개발을 제안하고자 한다. 넷째, 전통음식·먹거리 항목으로 구성된 ‘지역특색’ 요인에 대한 베트남관광객의 만족도가 높지 않은 편으로 이에 대한 만족도 향상을 위해서 불고기나 갈비, 김치찌개 위주의 획일적 식사제공이 아닌 보다 다양한 한국 음식문화를 체험할 수 있는 기회를 제공할 필요가 있겠다. 끝으로, 베트남관광객을 보다 확대 유치하기 위해서는 관광목적 한국방문 베트남관광객들을 위한 비자발급 절차가 간소화되어야 할 것이며 이를 통하여 보다 많은 베트남 관광객들이 한국을 방문할 수 있을 것으로 기대된다. The purpose of this research is to examine the influence of the satisfaction of each tourismdestination attraction on total tourist satisfaction and behavioral intention. In addition, this research aims to examine whether there are different relationships between groups, who has different tour behaviors. The results of the empirical study show that firstly, the factors such as ‘Destination feature’, ‘Convenience’, ‘Hospitalities’ and ‘Regional characteristics’ have a positive effect on total tourist satisfaction. But the factors such as ‘Finance’, ‘Enjoying’ and ‘Tourism activity’ have no effects on total tourist satisfaction. Secondly, total tourist satisfaction has a positive effect on behavioral intention. In addition, according to the tour behavior (in terms of the purpose of tour and the previous experiences of the destination) there are different between groups. These findings suggested that fundamental data for tourism policy to attract Vietnamese tourists to Korea. The contribution and limitations of this research were discussed and the future possible researches werementioned. 본 연구의 목적은 한국 방문 베트남 패키지 관광객을 대상으로 관광지 매력속성별 만족도와 전반적 관광만족도 및 행동의도간의 관계를 살펴보 고 동시에 관광행태에 따른 집단별 관광지 매력속성별 만족도와 전반적 관광만족도 및 행동의도간의 차이를 분석하는 것이다. 본 연구의 분석결과 통계적으로 한국관광지 매력속성별 만족도 7개 요인 중 ‘편의성’, ‘환대·쾌적성’, ‘관광지의 고유성’, ‘지역특색’ 등 4개 요인만이 전반적 관광만족도에 유의한 영향을 미친 것으로 분석되었는데, 이러한 4개 요인의 만족도 제고를 위하여 다음과 같은 시사점을 제시하고자 한다. 첫째, ‘편의성’에 대한 만족도를 더욱 높이기 위해서는 ‘기후’ 항목에 대한 만족도를 향상시키는 방안을 고려할 수 있다. 이를 위해 베트남의 기 후조건을 역이용한 다채로운 겨울계절 상품의 개발을 제안한다. 둘째, ‘환대·쾌적성’ 요인의 경우, 방한 베트남 관광객들의 평가에 따르면 한국관광지의 종업원 서비스에 불만이 많은 것으로 조사되었다. 따라서, 현장접점에 있는 직원들에게 베트남 문화 및 역사에 대한 교육의 실시를 제안한다. 셋째, ‘관광지의 고유성’ 요인의 경우 ‘자연․경관의 아름다움’에 대한 베트남관광객의 만족도는 가장 낮았는데, 이의 개선을 위해서 한국의 아름다운 자연자원과 베트남인들이 선호하는 한류콘텐츠를 효과적으로 융합한 상품개발을 제안하고자 한다. 넷째, 전통음식·먹거리 항목으로 구성된 ‘지역특색’ 요인에 대한 베트남관광객의 만족도가 높지 않은 편으로 이에 대한 만족도 향상을 위해서 불고기나 갈비, 김치찌개 위주의 획일적 식사제공이 아닌 보다 다양한 한국 음식문화를 체험할 수 있는 기회를 제공할 필요가 있겠다. 끝으로, 베트남관광객을 보다 확대 유치하기 위해서는 관광목적 한국방문 베트남관광객들을 위한 비자발급 절차가 간소화되어야 할 것이며 이를 통하여 보다 많은 베트남 관광객들이 한국을 방문할 수 있을 것으로 기대된다. The purpose of this research is to examine the influence of the satisfaction of each tourismdestination attraction on total tourist satisfaction and behavioral intention. In addition, this research aims to examine whether there are different relationships between groups, who has different tour behaviors. The results of the empirical study show that firstly, the factors such as ‘Destination feature’, ‘Convenience’, ‘Hospitalities’ and ‘Regional characteristics’ have a positive effect on total tourist satisfaction. But the factors such as ‘Finance’, ‘Enjoying’ and ‘Tourism activity’ have no effects on total tourist satisfaction. Secondly, total tourist satisfaction has a positive effect on behavioral intention. In addition, according to the tour behavior (in terms of the purpose of tour and the previous experiences of the destination) there are different between groups. These findings suggested that fundamental data for tourism policy to attract Vietnamese tourists to Korea. The contribution and limitations of this research were discussed and the future possible researches werementioned.

Intervening in the Work-Family Interface

Wing-chung Ho,Chau-kiu Cheung 숙명여자대학교 아시아여성연구원 2011 Asian Women Vol.27 No.3

This study used both quantitative and qualitative data to illuminate structural constraints faced by mothers and their strategies used to manage work and childcare in low-income communities in Hong Kong, China. The data were drawn from a survey (N = 1,429) of mothers living in five communities. From these data, focus was on a subset (N = 764) of data covering two low-income communities, Tin Shui Wai and Sham Shui Po. Eventually a sample of this subset (N = 285) also participated in individual in-depth interviews. Results illustrate differences between mothers in their 30s and 40s in the decision on managing dual pressures of childcare and limited income. Accordingly, younger mothers were fully concerned with childcare, as their children were younger. As such, they put the idea of employment aside even though they faced financial hardship. In contrast, the older mothers suffered more from work-family conflict, as they more likely engaged in employment. Easing younger mothers’ childcare and older mothers’ work-family interplay is therefore a reasonable concern for public support for the mothers.

Incidence and Risk Factors for Implant Failure in Spinal Metastasis Surgery

Wong Yu Chung,Chau Wai Wang Jacky,Kwok Kin On,Law Sheung Wai 대한척추외과학회 2020 Asian Spine Journal Vol.14 No.6

Study Design: Retrospective study.Purpose: To investigate the incidence of symptomatic and asymptomatic implant failure in spinal metastasis surgery and identify potential risk factors.Overview of Literature: Surgical stabilization with instrumentation is an established method for the treatment of spinal metastasis. However, very few studies have investigated the incidence and risk factors for implant failure after spinal instrumentation surgery for the treatment of spinal metastasis.Methods: This study recruited 88 patients who received surgical stabilization with instrumentation for the treatment of spinal metastasis. Their medical records and postoperative X-rays were reviewed for evidence of implant failure. Statistical analysis with logistic regression was performed to assess nine potential risk factors for the development of implant failure, including patient’s age at operation, gender, survival, primary tumor, spinal level involved, construct length, decompression levels, fusion material utilization, and radiotherapy application either before or after surgery, to identify potential contributing risk factors.Results: Implant failure was identified in nine out of 88 cases (10.2%) with two cases requiring implant removal: one case included a progressive kyphosis that resulted in nonhealing sore and the other involved a deep-seated wound infection that spread to the implants. Another case required wound debridement due to superficial wound infection. The remaining six cases were asymptomatic, despite postoperative X-rays demonstrating evidence of implant failure. No patient required implant revision. Logistic regression analysis demonstrated that patients who received radiotherapy either before or after surgery were less likely to develop implant failure.Conclusions: The development of radiological implant failure following surgical treatment of spinal metastasis is common. However, symptomatic implant failure leading to revision surgery is uncommon. Our findings suggest that radiotherapy, either before or after spinal surgery, is not associated with the development of implant failure.

Development of a Fuzzy-Q Control for Achieving Robust Inverter Systems

Yu-Kai Chen,Chau-Chung Song 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

This paper presents a fuzzy control including the nonlinear effects of the output-filter inductor. Since the filter inductance will drop dramatically when the inverter system is operated at heavy loads, system dynamic performance will vary over a wide range. In the system, a linear relationship between quality factor Q and resonant peak Mr of theoutput filter can be derived. Therefore, Q-parameter is selected as an input variable of the fuzzy-Q control to improve the system performance by modifying the fuzzy rule. The inverter systems with the fuzzy-Q control scheme can compensate the influence due to variations of filter inductance and loads. Thus, a robust inverter system can be achievedwith the proposed fuzzy-Q control.

Historical Overview of Taenia asiatica in Taiwan

Hong Kean Ooi,Chau-Mei Ho,Wen-Cheng Chung 대한기생충학열대의학회 2013 The Korean Journal of Parasitology Vol.51 No.1

Hypoalbuminemia and obesity class II are reliable predictors of peri-prosthetic joint infection in patient undergoing elective total knee arthroplasty

Man Sheryl Lok-Chi,Chau Wai-Wang,Chung Kwong-Yin,Ho Kevin Ki Wai 대한슬관절학회 2020 대한슬관절학회지 Vol.32 No.-

Background: Malnutrition is a common and modifiable risk factor for postoperative complications and adverse outcomes in orthopedics. The purpose of this study was to identify biomarkers of malnutrition in patients undergoing elective total knee arthroplasty (TKA) that are predictive of adverse in-hospital postoperative complications, to facilitate the identification of at-risk patients for nutritional optimization before surgery. Methods: A total of 624 patients who underwent elective TKA between 2013 and 2017 were evaluated; potential biomarkers of preoperative malnutrition, including hypoalbuminemia (serum albumin < 3.5 g/dL), total lymphocyte count (TLC < 1500 cells/mm3), and body mass index (BMI), were assessed for any association with in-hospital postoperative complications. Results: The prevalence of hypoalbuminemia, low TLC, overweight, obesity class I, and obesity class II were, respectively 2.72%, 33.4%, 14.8%, 44.5%, and 26.9%. There was a significant association between hypoalbuminemia and obesity class II (BMI ≥ 30.0 kg/m2) with rates of peri-prosthetic joint infection, and no significant association between such complications and low TLC, overweight, or obesity class I. Logistic regression analysis showed that patients with hypoalbuminemia or being in obesity class II with gouty arthritis were more likely to suffer from periprosthetic joint infection. Conclusions: Hypoalbuminemia and obesity class II together is a reliable biomarker of preoperative malnutrition for predicting peri-prosthetic joint infection after elective TKA, whereas low TLC, overweight, and obesity class I were not significantly associated with an increased risk of such complications.

No difference in long-term functional outcomes or survivorship after total knee arthroplasty with or without computer navigation: a 17-year survivorship analysis

( Ng Jonathan Patrick ),( Lau Lawrence Chun Man ),( Chau Wai-wang ),( Ong Michael Tim-yun ),( Cheung Kin Wing ),( Chiu Kwok Hing ),( Chung Kwong Yin ),( Ho Kevin Ki-wai ) 대한슬관절학회 2021 대한슬관절학회지 Vol.33 No.-

Background: The literature comparing the long-term outcomes and survivorship of computer navigation-assisted and conventional total knee replacement (TKR) is sparse. Moreover, of the available comparative studies with followup duration of more than 10 years, the results seem to be conflicting. The purpose of this long-term study was to compare the clinical and radiological outcomes, and implant survivorship, of TKR performed with and without computer navigation. Methods: We retrospectively compared the results of 49 computer-navigated TKRs and 139 conventional TKRs. The mean age of the patients was 67.9 (range 52-81) years for the navigation group and 67.1 (range 50-80) years for the conventional TKR group. The mean duration of follow-up for the conventional and navigation TKR groups was 12.9 and 13.2 years, respectively. Clinical and radiographic follow-up examinations of the patients were performed at 2 weeks, 1 month, 3 months and 6 months post-operatively, and at 1-year intervals thereafter. Results: There were no significant differences in the post-operative Knee Society knee and function score between the two groups. The mean overall deviation from neutral alignment and the radiological outliers were significantly higher in the conventional TKR group. The overall survival rates at 17 years were 92.9% for the navigation group and 95.6% for the conventional TKR group (p = 0.62). Conclusions: Navigated TKR resulted in fewer radiological outliers; however, this did not translate to better long-term functional outcomes or implant survival.

Sequence and phylogenetic analysis of the gp200 protein of Ehrlichia canis from dogs in Taiwan

Chia-Chia Huang,Yu-Chen Hsieh,Chau-Loong Tsang,Yang-Tsung Chung 대한수의학회 2010 JOURNAL OF VETERINARY SCIENCE Vol.11 No.4

Ehrlichia (E.) canis is a Gram-negative obligate intracellular bacterium responsible for canine monocytic ehrlichiosis. Currently, the genetic diversity of E. canis strains worldwide is poorly defined. In the present study, sequence analysis of the nearly full-length 16S rDNA (1,620 bp) and the complete coding region (4,269 bp) of the gp200 gene, which encodes the largest major immunoreactive protein in E. canis, from 17 Taiwanese samples was conducted. The resultant 16S rDNA sequences were found to be identical to each other and have very high homology (99.4~100%) with previously reported E. canis sequences. Additionally, phylogenetic analysis of gp200 demonstrated that the E. canis Taiwanese genotype was genetically distinct from other reported isolates obtained from the United States, Brazil, and Israel, and that it formed a separate clade. Remarkable variations unique to the Taiwanese genotype were found throughout the deduced amino acid sequence of gp200, including 15 substitutions occurring in two of five known species-specific epitopes. The gp200 amino acid sequences of the Taiwanese genotype bore 94.4~94.6 identities with those of the isolates from the United States and Brazil, and 93.7% homology with that of the Israeli isolate. Taken together, these results suggest that the Taiwanese genotype represents a novel strain of E. canis that has not yet been characterized.