• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.3
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• pp.891-910
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• 2021

Previous QoS-aware service composition methods mainly focus on how to generate composite service with the optimal QoS efficiently for a single request. However, in the real application scenarios, there are multiple service requests and multiple service providers. It is more important to compose services with suboptimal QoS and maintain the load balance between services. To solve this problem, in this paper, we propose a service composition method, named as dynamically change and balancing composition method (DCBC). It assumes that the QoS of service is not static, and the services can adjust the value of QoS to gain more opportunities to be selected for composition. The method mainly includes two steps, which are the preprocessing step and the service selection step. In the preprocessing step, a backward global best QoS calculation is performed which regarding the static and dynamic QoS respectively; then guided by the global QoS, the feasible services can be selected efficiently in the service selection step. The experiments show that the DCBC method can not only improve the overall quality of composite services but also guarantee the fulfill ratio of requests and the load balance of services.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2001.10a
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• pp.286-289
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• 2001

This paper deals with the procedures of effective mid-term Operation Planning establishment for painting shop in shipbuilding. and develop prototype system. In general, the block painting process consists of two stages such as blasting operation for surface preparation and painting operation for paint application for blocks. Weather condition is a potent Influence on those operations. The procedures consists of four steps, Load analysis, Generate alternative simulation plan. Implementation of Allocation automation module and Compare result of each simulation plan. Explain of each step. as follows, 1.step, Load analysis measure amount of assigned workload and manhour. 2.step, simulation scheme include alterable control variable such as overtime, weather. Auto allocating module carry out feasibility of simulation plan. 3.step, Allocation automation module are composed of three algorithms, as followings: - the block allocation algorithm that determines the number of blocks to be processed each day, - the team allocation algorithm that allocates blocks to worker groups. - the block arrangement algorithm that arrange blocks in blasting and painting cells. Since the block arrangement algorithm is conducted simultaneously with the team allocation algorithm, the total structure of the operating algorithms is considered to have two phases: first, daily load balancing with capacity limit and second, team allocation considering arrangement each day 4 step, Comparing result of each simulation plan. and select best simulation plan.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.04a
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• pp.85-91
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• 2002

Of all the many types of machine elements which exist today, gears are among the most commonly used. Many researches have been done to manufacture helical gears by cold forging and extrusion. Although cold forging and extrusion were applied to some bevel, spur, and helical gears, problems in connection with reducing forming load and tool life still make it difficult for the related methods to be commercialized. In this study, focusing on reducing load in forming helical gears, extrusion of helical gears by a two-step process is proposed. The process is composed of an extrusion step of spur gears used as preform and a torsion step of the preform to make helical gears. Upper-bound analysis for the two-step process is performed and compared with results of experiments. The newly proposed method can be used as an advanced forming technique to remarkably reduce the forming load and replace the conventional forming process of helical gears.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.824-828
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• 2002

Of all the many types of machine elements which exist today, gears are among the most commonly used. Many researches have been done to manufacture helical gears by cold forging and extrusion. Although cold forging and extrusion were applied to some bevel, spur, and helical gears, problems in connection with reducing forming load and tool life still make it difficult for the related methods to be commercialized. In this study, focusing on reducing load in forming helical gears, extrusion of helical gears by a two-step process is proposed. The process is composed of an extrusion step of spur gears used as preform and a torsion step of the preform to make helical gears. Upper-bound analysis for the two-step process is performed and compared with results of experiments. The newly proposed method can be used as an advanced forming technique to remarkably reduce the forming load and replace the conventional forming process of helical gears.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.44 no.3
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• pp.270-273
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• 1995

This paper proposes an optimal load shedding algorithm by which the system loss can be minimized when the load shedding is unavoidable in case of severe contingency such as the outage of key generators or lines. Shedding load .DELTA.S = .DELTA.P + J.DELTA.Q(MVA) is performed on the weakest bus (on the view of voltage stability), step by step, by the priority of the I.DELTA. = SQRT(.lambda.$\_$P/$\^$2/ + .lambda.$\_$Q/$\^$2/) index given for each load bus, where .lambda.$\_$P/ and .lambda.$\_$Q/ are the sensitivity indices representing the system loss variation versus active and reactive power change of the bus load bus. All loads are assumed to be constant power loads for convenience. A 5 bus sample system proves the effectiveness of the algorithm proposed.

• Proceedings of the ESK Conference
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• 1997.10a
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• pp.168-176
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• 1997

The purpose of this study is to know load for each human body's knee joint to endure load efficiently, when weight lifter pulls suitable bar in the each weight lifting level. To use the difference of load and correlation between men and women, the conclusion of this stduy is to find parameters to conduct maximum limitation of maximum load to search maximum limitation. The moment of each joint in the lower area was to have a much difference between group of the turunk in the first step. It decreased rapidly until decent and greatly pulled in the second step. Neuromusclar moment increased suddenly in the decrease phase. This phenomenon resulted from shock-absorbing function to sbsorb a load from bar.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.3
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• pp.465-471
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• 2007

The one step type pole and two step type pole are used in KEPCO's distribution system. The neutral current increases in three-phase four-wire distribution system due to unbalanced load. Usually, power line and communication line are installed at contiguity by effect of topography in Korea. To this end, the damages such as electrostatic induction, electromagnetic induction and harmonic induction generated by induced voltage and current are occured in power line and communication line. This paper calculates the neutral current in KEPCO's distribution system using EMTP by composing various simulated conditions. Also, these results are verified by vector analysis.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.2
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• pp.231-240
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• 1988

An investigation is carried out for the load capacity characteristics of the externally pressurized air lubricated journal bearings both theoretically and experimentally. Theoretical analysis is made using the incremental method and the finite element method, and the discharge coefficient is considered. The experiments are performed for five bearings which are produced according to the rows of supply holes and the presence of poket or step. The results are compared with the numerical results. The present numerical results are in better agreement with the available experimental results than any other earlier numerical results for the bearings having one row and two rows of supply holes with pocket. The present numerical and experimental results show that the bearing with step has larger load capacity than that without step and that the load capacity increases as the clearance ratio increases.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.652-655
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• 2003

In this paper, step-down piezoelectric transformer is studied. The piezoelectric transformer, made of lead zirconate titanate solid solution ceramic, is operated by a fundamental contour-extensional vibration mode. The transformer of 14mm length, 14mm width and 4.5mm thickness was made up two shape(Type I and II). The resonant frequency (fr) is 144kHz and 128kHz at the load resistant of $7.5{\Omega}$ that is a similar to calculating matching impedance. The gain (G) obtained 0.19 and 0.08 at each resonant frequency, when applied input voltage is 25V. The temperature difference with the variation of load resistant was increased with increasing load resistant and was the lowest at $7.5{\Omega}$ near the matching of output impedance.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.4
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• pp.332-336
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• 2007

In this study, multilayer piezoelectric transformer was manufactured using the PMN-PNN-PZT ceramic and then the electrical characteristics were investigated according to the variations of frequency and load resistance. The voltage step-up ratio of multilayer piezoelectric transformer showed the maximum value at the vicinity of 75 kHz and increased according to the increase of load resistance. When the output impedance coincided with the load resistance, the multilayer piezoelectric transformer showed the temperature rise of less than $20^{\circ}C$ at the output power of 20 W. As the results, the multilayer piezoelectric transformer manufactured at low co-firing temperature of $940^{\circ}C$ using PMN-PNN-PZT ceramics could be stably driven as the step-down transformers.