• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.1
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• pp.35-41
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• 2010

An overload limiter is used to prevent its overturning accident during an operation of a movable crane. Recently the indirect measuring method, which measures hoisting load and overturning moment of overload limiter, demands instead of the existing method, which measures only hoisting load. The indirectly measuring method is how to conduct the hoisting load and overturning moment as measuring the load of hydraulic cylinder for a luffing driving of boom. So we need to develop the multi-angular pin type load cell with the measuring angle of ${\pm}10$ degree instead of the existing load cell with the measuring angle of ${\pm}2$ degree. In this study the finite element analysis is conducted to evaluate the effect of the aspect ratio of measuring cross section on the measuring limit of the load cell to develop the many-angular pin type load cell. For this investigation, the aspect ratio of measuring cross section and load applying angle were adopted as design parameters and the stresses of measuring part were evaluated for each parameter.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.7
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• pp.477-482
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• 2011

In the present study, the performance characteristics of the heat pump chiller under heating conditions were experimentally investigated. Capacity, input power and COP under overload, frost and defrost conditions were obtained. The experimental data for the heat pump chiller were measured using the air-enthalpy calorimeter and the constant temperature water bath. At overload condition, the heating capacity and COP increase about 25.7% and 19.1%, respectively. The variations of the evaporator, the compressor outlet and the condenser temperature were obtained under frost and defrost conditions. The frost and defrost period of the heat exchanger decreases about 36.0~56.1%.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.7
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• pp.1121-1127
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• 2016

In this paper, modeling of overcurrent relay(OCR) to protect domestic AC electric railway Auto Transformer(AT) feeding system and operation characteristic analysis on overload condition are described. The target system of this paper is actual site where overload trip of circuit breaker occurs frequently. Because this AT feeding system is made of parallel single track which had a load(electric train) respectively, and is connected with only T phase of Scott Transformer. In addition, this system has been feeding 66kV voltage by KEPCO, not 154kV. We focus on protective coordination of Scott Transformer primary side and secondary side OCR for Korea single track AC electrical railway system in operation currently. We modeled single track AT feeding system and OCR. Also we performed faults and overload analysis for verification of OCR's setting values and system modeling. To analyze above mentioned research, we used PSCAD/EMTDC software tool.

• Journal of the Korea Safety Management & Science
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• v.23 no.4
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• pp.93-104
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• 2021

In this paper, we propose a method for diagnosing overload and working load of collaborative robots through performance analysis of machine learning algorithms. To this end, an experiment was conducted to perform pick & place operation while changing the payload weight of a cooperative robot with a payload capacity of 10 kg. In this experiment, motor torque, position, and speed data generated from the robot controller were collected, and as a result of t-test and f-test, different characteristics were found for each weight based on a payload of 10 kg. In addition, to predict overload and working load from the collected data, machine learning algorithms such as Neural Network, Decision Tree, Random Forest, and Gradient Boosting models were used for experiments. As a result of the experiment, the neural network with more than 99.6% of explanatory power showed the best performance in prediction and classification. The practical contribution of the proposed study is that it suggests a method to collect data required for analysis from the robot without attaching additional sensors to the collaborative robot and the usefulness of a machine learning algorithm for diagnosing robot overload and working load.

• Bulletin of the Society of Naval Architects of Korea
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• v.26 no.2
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• pp.41-48
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• 1989

This paper investigates the relationship between strain hardening exponents(n) of various marine materials and fatigue crack retardation effect after applying single overload. Using the four different sheet materials, following results are obtained. (1) The fatigue crack propagation rate after applying single overload was retarded and the effects of this retardation were closely related to the strain hardening exponent. (2) The larger the strain hardening exponents were, the more were the fatigue crack retardation effects after applying single overload. (3) The considerable crack closure with the applying of a overload was observed in matrals with large strain hardening exponent. When n is smaller than 0.1, the fatigue crack retardation effects are negligible. On the contrary, when n is larger than 0.2 the fatigue crack retardation effects are significant.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.4
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• pp.744-751
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• 2006

Even many kinds of Internet-based services have been generated due to the great development of the Internet. PSTN still exists in the center of the national infrastructure network and the transit exchanges will be maintained the core roles in PSTN for many years in the future. These transit exchanges often suffer from unexpected overload situation because they have to process Intelligent Network calls and mobile calls additionally as well as POTS (Plain Old Telephone Service). In this paper, we suggest an efficient overload control algorithm for the distributed transit switching system under the various types of call services. We also show that this algorithm can be implemented easily cooperating with the network management control functions. The simulation technique is used to show that the proposed algorithm effectively controls calls and maintains safely the call processor's load under the various kinds of overload situations.

• The Journal of the Korea Contents Association
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• v.8 no.9
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• pp.251-258
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• 2008

Many approaches exist for studying travel service quality, employee's satisfaction, and traveler' satisfaction. Although tour conductor play an important role in travel service, there is a lack of research on how to conceptualize and measure tour conductor's role, role stress and service delivery level. So this paper presents a conceptual framework and research approach for examining the role conflict, ambiguity, overload, and service delivery level of tour conductor in group package and the impacts of role stress on service delivery level. Results indicate that there are significant affection on service delivery level of TC among the role conflict, ambiguity, and overload. For the most part, the role conflict and ambiguity more impacted on responsibility and empathy with service encounter, the role overload affected on professional and tangibles. In conclusion, the studies reported here highlight the importance of individual effort as well as organizational police in reducing strain and improving service delivery level.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.3
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• pp.225-232
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• 2008

Overload vehicles operate damage to road, bridge, and then increasing in maintenance and repair cost because structures are reduced durability. The existing regulation systems have many problems and need coping measure. Therefore, this paper organized Ubiquitous sensor network system for development of intelligent auto overload vehicle regulation system about high speed vehicles, also axial load WIM sensor was selected by indoor experiment through wireless protocol. And we examined possibility U-load auto overload vehicle regulation system through experiment of the transmission and reception distance. If this system will apply to road and bridge, might be effective for economy and convenience through establishment of U-IT system. And high speed vehicle that was amalgamate IT technology and existing overload regulation problems, also tested wireless sensor for USN organization. This experiment aim to organize system interface for user through perfection man-less, wireless system of Internal/External Network from high speed WIN sensor with USN organization. Accordingly, it is necessary experimentation through Test Bed for constitution External network and application of actually regulations using WCDMA/HSDPA.

• International Commerce and Information Review
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• v.14 no.4
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• pp.361-383
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• 2012

This study examined the determinants of distributor stress and organizational effectiveness in a global distribution industry. This study suggested distributors' role factors and mindfulness as the key determinants of their stress and organizational effectiveness. Employees' role factors were classified into three factors: role ambiguity, role conflict, and role overload. Organizational effectiveness was classified into three factors: job satisfaction, organizational commitment, and turnover intention. Data were collected from 202 distributors in a global distribution industry. Results indicated that role conflict and role overload were significantly, positively related to distributors' stress, and that role ambiguity and mindfulness were negatively related to their stress. Results also indicated that role ambiguity was negatively related to job satisfaction and organizational commitment, and that role conflict and role overload were positively related to turnover intention. Finally, role overload was positively related to job satisfaction and organizational commitment and mindfulness was positively related to job satisfaction.

• Fashion & Textile Research Journal
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• v.21 no.2
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• pp.141-150
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• 2019

Online recommendation services help people search for an appropriate product among a huge assortment in stores that also minimize consumers' choice overload. People with a need for uniqueness are likely to prefer this online recommendation service based on individual needs and tastes. This study verifies the effect of consumers' choice overload and similarity avoidance in consumers' evaluation towards an online recommendation service with a focus on innovativeness and use comparability. Two-hundred consumers participated in this study and data were collected through an online survey firm. A mock retailer's webpage was created and showed six types of sneakers, which was presented as a result of product recommendation based on consumers' personal information. Data was analyzed using confirmatory factor analysis (CFA), analysis of variance (ANOVA), and regression analysis. The results show that people with a high similarity avoidance perceive an online recommendation service as an innovative and compatible service. They also perceive a high level of use compatibility for an online recommendation service, especially when it is difficult to choose a product under choice overload. Innovativeness and use compatibility of an online recommendation service increase behavioral intention. The results of this study can contribute to strategies to start online recommendation services from online retailers' websites that identify circumstances in which consumers can adopt innovative services in a positive manner.