• 로봇학회논문지
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• 제17권1호
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• pp.40-47
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• 2022

A reward function suitable for a task is required to manipulate objects through reinforcement learning. However, it is difficult to design the reward function if the ample information of the objects cannot be obtained. In this study, a demonstration-based object manipulation algorithm called stochastic exploration guided by demonstration (SEGD) is proposed to solve the design problem of the reward function. SEGD is a reinforcement learning algorithm in which a sparse reward explorer (SRE) and an interpolated policy using demonstration (IPD) are added to soft actor-critic (SAC). SRE ensures the training of the critic of SAC by collecting prior data and IPD limits the exploration space by making SEGD's action similar to the expert's action. Through these two algorithms, the SEGD can learn only with the sparse reward of the task without designing the reward function. In order to verify the SEGD, experiments were conducted for three tasks. SEGD showed its effectiveness by showing success rates of more than 96.5% in these experiments.

• 반도체디스플레이기술학회지
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• 제22권2호
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• pp.40-44
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• 2023

The defect detection based on deep learning requires minimal loss and high accuracy to pinpoint product defects. In this paper, we confirm the loss rate of deep learning training based on disc-shaped artificial scaffold images. It is intended to compare the performance of Cross-Entropy functions used in object detection algorithms. The model was constructed using normal, defective artificial scaffold images and category cross entropy and sparse category cross entropy. The data was repeatedly learned five times using each loss function. The average loss rate, average accuracy, final loss rate, and final accuracy according to the loss function were confirmed.

• Industrial Engineering and Management Systems
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• 제14권1호
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• pp.73-87
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• 2015

The development of a practical technology intelligence system requires a knowledge base that structures the core information and its relationship distilled from large volumes of technical data. Previous studies have mainly focused on the methodological approaches for technology opportunities, while little attention has been paid to constructing a practical knowledge base. Therefore, this study proposes a procedure to construct a function-based knowledge base for technology intelligence. We define the product-function-technology relationship and subsequently present the detailed steps for the knowledge base construction. The knowledge base, which is constructed analyzing 1110582 patents between 2009 and 2013 from the United States Patent and Trademark Office database, contains the functional knowledge of products and technologies and the relationship between products and technologies. This study is the first attempt to develop a large-scale knowledge base using the concept of function and has the ability to serve as a basis not only for furthering technology opportunity analysis methods but also for developing practical technology intelligence systems.

• Journal of Information Technology Applications and Management
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• 제23권4호
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• pp.117-125
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• 2016

Software reliability in the software development process is an important issue. In infinite failure non-homogeneous Poisson process software reliability models, the failure occurrence rates per fault. can be presented constant, monotonic increasing or monotonic decreasing pattern. In this paper, the reliability software cost model considering decreasing intensity function was studied in the software product testing process. The decreasing intensity function that can be widely used in the field of reliability using power law process, log-linear processes and Musal-Okumoto process were studied and the parameter estimation method was used for maximum likelihood estimation. In this paper, from the software model analysis, we was compared by applying a software failure interval failure data considering the decreasing intensity function The decreasing intensity function model is also efficient in terms of reliability in the arena of the conservative model can be used as an alternating model can be established. From this paper, the software developers have to consider life distribution by preceding information of the software to classify failure modes which can be gifted to support.

• 보건의료산업학회지
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• 제6권2호
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• pp.57-69
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• 2012

The purpose of this study was to investigate correlation with self-care behaviors and physiological index according to cognitive function of hemodialysis patients. The data were collected from 108 patients on hemodialysis in university hospital. The period of data collection was from January 4 to January 31, 2010. The instruments of research were MMSE, Self-care behavior scale for hemodialysis patients. The 17.6% of patients showed the cognitive disorder. Self-care behaviors of patients showed that normal cognitive function group was significantly higher than dysfunction group. Creatinine and parathyroid hormone of patients showed that normal cognitive function group was significantly lower than dysfunction group. The cognitive function of patients showed positive correlations with self-care behavior(r=.283, p=.003) and Kt/V(r=.214. p=.026), showed significant negative correlations with phosphorus(r=-.223, p=.020) and creatinine(r=-.318, p=.001). The results of this study can be used to develop nursing education program to improve self-care behaviors according to cognitive function of hemodialysis patients.

• 국제물리치료학회지
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• 제11권3호
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• pp.2113-2118
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• 2020

Background: Patients with stroke have core muscle weakness and limited rib cage movement, resulting in restrictive lung disease. Objectives: To examine the comparison of effects of rib cage joint mobilization combined with diaphragmatic breathing exercise and diaphragmatic breathing exercise on the pulmonary function and chest circumference in patients with stroke. Design: A cluster randomized controlled trial. Methods: Twenty-four patients were randomly assigned to an experimental group (rib cage joint mobilization combined with diaphragmatic breathing exercise group) and control group (diaphragmatic breathing exercise group). Patients in the experimental group underwent rib cage joint mobilization for 15 min and diaphragmatic breathing exercise for 15 min. The control group underwent diaphragmatic breathing exercise for 30 min. Both groups underwent exercise thrice a week for 4 weeks. The pulmonary function and chest circumference were measured using the MicroLab spirometer and a tape measure, respectively. Results: After the intervention, the pulmonary function and chest circumference significantly improved in both groups. These improvements were significantly higher in the experimental group than those in the control group. Conclusion: Rib cage joint mobilization combined with diaphragmatic breathing exercise improves pulmonary function and chest circumference in patients with stroke.

• 한국세라믹학회지
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• 제47권5호
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• pp.373-380
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• 2010

In this study, we studied on the durability of restorative cement mortar for deteriorated concrete at complex deteriorated conditions as variation of temperature and of humidities. We made a comparison between restorative materials with insulation function and restorative materials without insulation function in items of compressive and bending strength and permeability of water, durability for carbonation, salt damage, diffusion coefficient of salt at complex deterioration conditions like change of temperature, change of humidity, For insulation, we used close-pore type Alumino-Silicate lightweight aggregate and substituted 12 wt% and 15 wt% out of original restorative cement mortar without insulation function. As a result, it was found that original restorative cement mortar without insulation function fail to meet Korean Standard on polymer modified cement mortar for maintenance in concrete structure, but restorative cement mortar with insulation function is in contentment Korean Standard to meet excellent than restorative materials without insulation function for durability at complex deteriorated conditions.

• PNF and Movement
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• 제18권1호
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• pp.117-126
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• 2020

Purpose: The purpose of this study was to investigate the effects of extracorporeal shock-wave therapy (ESWT) on pain, grip strength, and upper-extremity function in patients diagnosed with lateral epicondylitis and to provide an effective intervention method for lateral epicondylitis. Methods: Twenty patients with lateral epicondylitis were randomly assigned to the ESWT group (n = 10) and the stretching exercise group (n = 10). Interventions in both groups were performed six times twice a week for three weeks. The visible analog scale (VAS) was used to measure pain change. A dynamometer was used to measure grip strength (GS). Patient-rated tennis elbow evaluation (PRTEE) was used to measure the upper-extremity function. Results: There were significant differences in pain, grip strength, and upper-extremity function in both groups before and after intervention (p < 0.05). There were also significant differences in pain, grip strength, and upper-extremity function between the groups after intervention (p < 0.05). Conclusion: This study showed very positive improvement in pain, grip strength, and upper-extremity function after ESWT in patients with lateral epicondylitis. Therefore, ESWT can be recommended for patients with lateral epicondylitis.

• PNF and Movement
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• 제18권3호
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• pp.445-452
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• 2020

Purpose: The purpose of this study was to evaluate the analysis of the association between upper extremity function and the Wolf Motor Function Test (WMFT) for chronic hemiparetic stroke patients and investigate the evidence of the WMFT as a clinical tool of upper extremity function in individuals with chronic hemiparetic stroke. Methods: This study applied an observational, cross-sectional design in outpatients at three local rehabilitation units in Seoul. Forty-nine individuals who had a diagnosis of first stroke participated in this study. All participants were analyzed for four clinical measures, including the Box and Block Test (BBT), the WMFT, grip strength, and the Canadian Occupational Performance Measure (COPM). Results: Upon analysis, a significant relationship was found between the WMFT scores and BBT scores as well as the grip strength. The WMFT score was statistically and positively associated with the COPM satisfaction score; however, it was not related to the COPM performance score. Conclusion: The results of this study suggest that the WMFT is positively related to simple tasks, such as hand muscle strength and manual dexterity. However, the WMFT does not have a relationship with complex tasks, which are measured by COPM performance abilities.

• Journal of Positioning, Navigation, and Timing
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• 제5권2호
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• pp.75-85
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• 2016

The performance of up-to-date mapping functions and various mean temperature equations were analyzed to derive optimal mapping function and mean temperature equation when GNSS precipitable water vapor (PWV) was investigated in the Korean Peninsula. Bernese GNSS Software 5.2, which can perform high precision GNSS data processing, was used for accurate analysis, and zenith total delay (ZTD) required to calculate PWV was estimated via the Precise Point Positioning (PPP) method. GNSS, radiosonde, and meteorological data from 2009 to 2014 were acquired from Sokcho Observatory and used. ZTDs estimated by applying the global mapping function (GMF) and Vienna mapping function 1 (VMF1) were compared with each other in order to evaluate the performance of the mapping functions. To assess the performance of mean temperature equations, GNSS PWV was calculated by using six mean temperature equations and a difference with radiosonde PWV was investigated. Conclusively, accuracy of data processing was improved more when using VMF1 than using GMF. A mean temperature equation proposed by Wu (2003) had the smallest difference with that in the radiosonde in the analysis including all seasons. In summer, a mean temperature equation proposed by Song & Grejner-Brzezinska (2009) had the closest results with that of radiosonde. In winter, a mean temperature equation proposed by Song (2009) showed the closest results with that of radiosonde.