• Journal of applied mathematics & informatics
• /
• 제27권1_2호
• /
• pp.259-266
• /
• 2009

We consider an M/G/1 feedback retrial queue with Bernoulli schedule in which after being served each customer either joins the retrial group again or departs the system permanently. Using the supplementary variable method, we obtain the joint generating function of the numbers of customers in two groups.

• 한국전문물리치료학회지
• /
• 제12권1호
• /
• pp.36-44
• /
• 2005

The purpose of this study was to examine the effects of self-controlled learning using the (KR) feedback schedule versus the yoked KR on the acquisition and retention of balance training for individuals with hemiplegics. Sixteen hemiplegics were randomly assigned to either a self-controlled or yoked KR group. All subjects were ambulatory with or without an assistive device. The self-controlled group was provided with feedback whenever they requested it, whereas the yoked group had no influence on the feedback schedule. All subjects performed 10 acquisition trials and 10 retention trials the day after acquisition. The data were analyzed using an independent t-test and a Mann-Whitney U test. Participants in the self-controlled group achieved significantly more effective learning than the yoked group during the acquisition and retention test except anterior/posterior (AP) body sway. These results suggest that a feedback schedule which is controlled by the individuals with hemiplegics may be more effective in balancing training than a yoked KR which is not controlled by the subject.

• 한국지능시스템학회논문지
• /
• 제21권6호
• /
• pp.712-717
• /
• 2011

최근 스마트 기기 사용자의 효율적인 일정 관리를 위해 다양한 일정 관리 에이전트들이 연구되고 있지만 아직까지는 일정을 기록하거나 확인해주는 수준에 머물고 있다. 사용자의 일정을 효율적으로 관리하기 위해서는 계획한 일정의 수행 여부 등을 모니터링하여 사용자에게 일정을 제대로 수행할 수 있도록 도움을 주거나, 새로운 일정 수립 시 사용자의 일정 수립 패턴에 적합하게 일정을 계획할 수 있도록 피드백 해 줄 수 있어야 한다. 본 논문에서는 사용자가 일정을 수행하거나 새로운 일정을 계획할 때, 획득된 사용자 컨텍스트를 이용하여 사용자의 행동을 추론하고 사용자의 행동 패턴에 따른 일정 관련 피드백을 제공하는 일정 관리 에이전트를 제안한다. 본 에이전트에서는 수집된 사용자 컨텍스트 정보를 전처리 후 베이지안 네트워크에 적용하여 사용자의 행동을 추론한다. 또한 사용자 일정 수행 여부의 확인 및 새로운 일정 수립에 필요한 피드백을 제공하기 위해 사용자 일정과 위치 및 시간 컨텍스트에 대하여 컨텍스트 트리 패턴 매칭 기법을 적용하였으며, 모바일 환경에서 6주간의 사용자 시뮬레이션을 통해 검증하였다.

• Safety and Health at Work
• /
• 제7권3호
• /
• pp.194-200
• /
• 2016

Background: The influence of sociocultural factors on human reliability within an open sociotechnical systems is highlighted. The design of such systems is enhanced by experience feedback. Methods: The study was focused on a survey related to the observation of working cases, and by processing of incident/accident statistics and semistructured interviews in the qualitative part. In order to consolidate the study approach, we considered a schedule for the purpose of standard statistical measurements. We tried to be unbiased by supporting an exhaustive list of all worker categories including age, sex, educational level, prescribed task, accountability level, etc. The survey was reinforced by a schedule distributed to 300 workers belonging to two oil companies. This schedule comprises 30 items related to six main factors that influence human reliability. Results: Qualitative observations and schedule data processing had shown that the sociocultural factors can negatively and positively influence operator behaviors. Conclusion: The explored sociocultural factors influence the human reliability both in qualitative and quantitative manners. The proposed model shows how reliability can be enhanced by some measures such as experience feedback based on, for example, safety improvements, training, and information. With that is added the continuous systems improvements to improve sociocultural reality and to reduce negative behaviors.

• 국제물리치료학회지
• /
• 제9권4호
• /
• pp.1602-1607
• /
• 2018

This study examined the correlation between power error (PE) and velocity error (VE) according to the condition and frequency of self-controlled feedback (SCF) during knee extension. One hundred participants were randomly assigned to 30% SCF, 70% SCF, 30% yoked feedback (YF), 70% YF and control group, respectively. The SCF group was provided with feedback when they requested it, whereas the YF group did not influence the feedback schedule. Participants in the control group were not given any visual feedback during the experiment. The isotonic, isometric, and isokinetic dynamometer (PRIMUS RS, BTE, USA) was used to measure the power and velocity error during knee extension. The collected data was analyzed using a Pearson test and SPSS 21.0. The correlation between PE and VE according to the condition and frequency of feedback on each phase during knee extension was significant. Both PE and VE were significantly higher when the feedback was provided with high frequency, passive, and no feedback. Our study suggests that application of SCF can help to improve the proprioception of the healthy person while reducing errors through low frequency and active feedback.

• Journal of Ubiquitous Convergence Technology
• /
• 제1권1호
• /
• pp.28-34
• /
• 2007

Tree-based reliable multicast protocols provide scalability by distributing error-recovery tasks among several repair nodes. These repair nodes perform local error recovery for their receiver nodes using the data stored in their buffers. We propose a packet loss patterns adaptive feedback scheduling scheme to manage these buffers in an efficient manner. Under our scheme, receiver nodes send NAKs to repair nodes to request packet retransmissions only when the packet losses are independent events from other nodes. At dynamic and infrequent intervals, they also send ACKs to indicate which packets can be safely discarded from the repair node's buffer. Our scheme reduces delay in error recovery because the requested packets are almost always available in the repair node's buffers. It also reduces the repair node's workload because (a) each receiver node sends infrequent ACKs with non-fixed intervals and (b) their sending times are fairly distributed among all the receiver nodes.

• 의학교육논단
• /
• 제19권1호
• /
• pp.47-55
• /
• 2017

This study was conducted to analyze the strengths and weaknesses of a 3-week family medicine clerkship program based on the results of an online survey taken by the students (N=127) and a structured interview with a focus group (n=10), aimed to improve the quality of the clerkship program. The online survey contained questions pertaining to goals, schedule, contents, arrangement, atmosphere, environment, evaluation, and satisfaction regarding the clerkship. The focus group interview addressed the schedule and achievements of the program. Scores were reported on a 5-point Likert scale. Most students were highly satisfied with the overall quality of the clerkship. The structured interview results showed that 97.6% of the clerkship program was executed according to the schedule. The focus group reported a perfect score of 5 points on several measures including: accomplishment of the educational goals of the family medicine clerkship, providing many chances to obtain medical histories and perform physical examinations on real patients, experience with various symptoms and diseases, positive attitudes of faculty members when teaching, notification of the guidelines for evaluation beforehand, well-constructed and effective clerkship schedule, and reflection of student feedback. However, the focus group gave low scores on: support for health accidents of students, access to patient information, enough opportunities to practice clinical skills, appropriate rest facilities for students, and fairness of clerkship evaluation process. In conclusion, the structured evaluation performed after the 3-week clerkship program motivated students and helped them ensure an efficient clerkship. This structured evaluation also suggested basic data to make the professor who is subject of the assessment. This study shows that structured assessment is an effective method which can be used to improve the quality of clerkships.

• 한국전문물리치료학회지
• /
• 제8권1호
• /
• pp.9-19
• /
• 2001

During therapy sessions, feedback is often provided concurrently by the physical therapist as the patient attempts to perform a movement and after the movement attempt. This feedback is provided to enhance the patient's balance abilities. However, recent studies in nondisabled populations have suggested that frequent feedback may be detrimental to retention or learning of motor skills. This study compared the effects of 100% relative frequency of knowledge of performance (KP) with 66% relative frequency of KP for motor learning on balance retraining in patients with hemiplegia. Twenty patients with hemiplegic were randomly assigned to one of two experimental groups. The acquisition phase consisted of 16 blocks of 5 trials for 2 days (80 total practice trials). The retention phase consisted of 2 blocks of a short-term retention test, one day after the end of the acquisition phase and a long-term retention test, one week after the end of the short-term retention test. In the 100% feedback condition, participants received feedback after every practice trial. A faded KP schedule was used in the 66% condition. No significant differences were found between the two groups during all experimental phases (acquisition and retention phases), (p>.05). However, there were significant decreases in balance index for both groups of acquisition phase (p<.05). These results suggest that 66% relative frequency of KP is not more effective than 100% relative frequency of KP with respect to retention over time when hemiparetic patients attempt to learn balance.

• Journal of Communications and Networks
• /
• 제12권3호
• /
• pp.266-274
• /
• 2010

The efficient network resource management is one of the important topics in a real-time system. In this paper, we present a practical network resource management framework, control-theoretic packet scheduler (CPS) system. Using our framework, an operating system can schedule both input and output streams accurately and efficiently. Our framework adopts very portable feedback control theory for efficiency and accuracy. The CPS system is able to operate independent of the internal network protocol state, and it is designed to schedule packet streams in fine-grained time intervals to meet the resource requirement. This approach simplifies the design of the CPS system, and leads us to obtain the intended output bandwidth. We implemented our prototype system in Linux, and measured the performance of the network resource management system under various network QoS constraints. The distinctive features of our principles are as follows: It is robust and accurate, and its operation is independent of internal network protocols.

• 한국병원경영학회지
• /
• 제16권1호
• /
• pp.77-100
• /
• 2011

The purpose of this study is to the improvement of general hospital outpatients waiting time using Theory Of Constraints(TOC) methodology and to the development of a Reception Desk in general hospital. This study is to provide decision-making guidelines for hospital managers and to provide feedback for the efficiency of job process. The target people of the study are outpatients and Cashiers on Chungnam national university hospital in Daejeon. The methods of study are summarized as follows. First, The team managers from a Reception Desk group were appointed. This team managers have the adjustment authority to the Outpatients schedule of doctor and Cashier members. Second, The consolidation of the general Reception desk and special inspection the Reception Desk. A movement line and waiting time of patients were simple and fast to accept. As a result of study, it shows that the TOC is the method for a job process and waiting time improvement, patients' satisfaction increase and we need an objective measurement indexes in the medical treatment industry.