• The Transactions of the Korea Information Processing Society
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• v.6 no.12
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• pp.3456-3468
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• 1999

Most of previous parallel join algorithms assume a database partition system(DPS), where each database partition is owned by a single processing node. While the DPS is novel in the sense that it can interconnect a large number of nodes and support a geographically distributed environment, it may suffer from poor facility for load balancing and system availability compared to the database sharing system(DSS). In this paper, we propose a dynamic load balancing strategy by exploiting the characteristics of the DSS, and then extend the conventional hash join algorithms to the DSS by using the dynamic load balancing strategy. With simulation studies under a wide variety of system configurations and database workloads, we analyze the effects of the dynamic load balancing strategy and differences in the performances of hash join algorithms in the DSS.

• Journal of the Korean Society for Heat Treatment
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• v.33 no.6
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• pp.303-309
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• 2020

A vehicle's differential gear is a device designed to allow the vehicle's outer wheels to turn faster than the inner wheels when turning on a curve. The differential gear case is the main component of the differential gear system, which is composed of ring gear, pinion gear and side gear, and is fastened by pinion shaft pins. The differential gear case rotates when the vehicle is running, so balancing calibration is very important. In this study, a balancing machine that can diagnose and correct the differential gear case and mass imbalance of various rotating bodies was designed. The differential gear case was rotated at high speed to accurately diagnose the location and value of the unbalanced mass, and it was designed to be balanced and corrected by removing the unbalanced mass by drilling. After calibration, it was confirmed that the unbalanced value of all the measured samples was reduced to less than 180g.mm, and the unbalance reduction ratio was improved to 60~70%.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.7-8
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• 2015

In this paper a cell-to-cell fast charge balancing circuit for the Lithium-Ion battery module is proposed. In the proposed topology the energy in a high voltage cell is transferred directly to a low voltage cell through the operation of the dc-dc converter. Furthermore, the charge balancing can be performed regardless of the battery operation whether it is being charged, discharged or relaxed. The monitoring circuit composed of a DSP and a battery monitoring IC is designed to monitor the cell voltage and detect the inferior cell thereby protecting the battery module from failure. In order to demonstrate the performance of the proposed topology, a prototype circuit was designed and applied to 12 Lithium-Ion battery module. It has been verified with the experiments that the charge equalization time of the proposed method was shorter compared with those of other methods.

• Journal of International Academy of Physical Therapy Research
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• v.12 no.2
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• pp.2370-2374
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• 2021

Background: Masticating is an activity that is free from temporal or spatial constraints, with an advantage that it can be combined easily with other treatment methods. While several studies have reported a positive effect of the intervention of chewing using the jaw on postural stability, only a few studies were conducted on stroke patients. Objectives: To investigated the effects of masticating chewing gum on the static and dynamic balancing of stroke patients. Design: Randomized cross-over study design. Methods: Nineteen stroke patients were randomly assigned to the chewing group or control group. BT4 was used to measure the static and dynamic balancing abilities. Pre-test measurements were taken before mastication of chewing gum, and post-test measurements were taken after 2 days. The stroke patients in the chewing group were guided to sit on a chair and chew gum for 3 min, and their balancing abilities were simultaneously measured. The balancing abilities of the control group patients were measured while they sat at rest without masticating chewing gum. Results: The chewing group showed significant increases in the measures of static balance (i.e., C90 area, trace length, X mean, and Y mean). In the between-group comparison, the measures of static balance were significantly higher in the chewing group than in the control group. Conclusion: These findings suggest that masticating chewing gum enhanced the static balancing ability of stroke patients. Thus, gum chewing should be considered a viable clinical intervention to control posture in stroke patients.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.4
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• pp.348-355
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• 2022

A bipolar DC distribution system suffers from an imbalance in voltages when asymmetric loads are connected at the outputs. Dedicated voltage balancers are required to address the imbalance in bipolar voltage levels. However, additional components eventually increase the cost and decrease the efficiency and power density of the system. Therefore, to deal with the imbalance in output voltages without adding any extra components, this study presents a coupled inductor-based voltage balancing technique with a dual-output CLL resonant converter. The proposed coupled inductor does not require extra magnetic components to balance the output voltages because it is the result of resonant inductors of the CLL tank circuit. It can also avoid complex control schemes applied to voltage balancing. Moreover, with the proposed coupled inductor, the CLL converter acquires good features including zero voltage and zero current switching. Detailed analysis of the proposed coupled inductor is presented with different load conditions. A 3.6-kW hardware prototype was built and tested to validate the performance of the proposed coupled inductor-based voltage balancing technique.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.5
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• pp.97-104
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• 2010

In this paper, mesh network structure is applied to solve the load balancing problems in the Grid database. Data of the Grid database is replicated to several node for enhanced performance. Therefore, load balancing for user's query is selected node that evaluated workload in it. Existing researches are using passive load balancing method that selected another node after then node overflowed workload. It is inefficient to be applied to Gird database that has a number of node and user's queries almost changes dynamically. The proposed method connected each node which includes the same data through mesh network structure. When user's query occurs, it select node that has the lowest workload. The performance evaluation shows that proposed method performs better than the existing methods.

• ETRI Journal
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• v.27 no.1
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• pp.110-113
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• 2005

The resilient packet ring (RPR) is a data optimized ring network, where one of the key issues is on load balancing for competing streams of elastic traffic. This paper suggests three efficient traffic loading algorithms on the RPR. For the algorithms, we evaluate their efficiency via analysis or simulation.

• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.281-282
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• 2011

본 연구에서는 DC마이크로그리드의 전력품질을 향상시키기 위한 에너지 저장장치의 Power Balancing 제어기법에 대하여 기술하고 있다. 제안하는 시스템의 동작 타당성을 체계적으로 분석하기 위해 PSCAD/EMTDC 소프트웨어를 이용한 마이크로그리드 모델을 개발하였으며 여러 사례 적용에 대한 모의실험을 통해 제어기법의 타당성을 검증하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.450-453
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• 2002

This paper is concerned with smooth walking robot using genetic algorithm. The new walking algorithm is proposed and we simulated and experimented the algorithm. We suggested the leg trajectory algorithm and balancing trajectory algorithm by applying genetic algorithm. First the leg trajectory algorithm generated the smooth trajectory. Also the balancing trajectory generated the optimal trajectory. We compared results with the previous walking algorithm. It showed that the new proposed algorithm generated the better walking trajectory.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.868-870
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• 2004

ad-hoc 망에서 라우팅 프로토콜의 부하균등(load balancing)은 이동성과 전송 지연사이의 trade-off로 인하여 성능 관점에서 중요한 이슈가 되어왔다. 부하균등을 고려한 SLAP(Simple Load-balancing Ad-hoc routing Protocol)이 제안되었으나 혼잡이 발생하거나 망의 토폴로지가 변화하였을 때 유연하게 대처하지 못한다. 본 논문에서는 ad-hoc 망에서 트래픽 혼잡 제어와 망의 이동성에 적응하기 위하여 동적인 임계치를 사용하는 부하균등 라우팅 프로토콜을 제안하였다. 제안된 프로토콜은 성능은 GloMoSim으로 시뮬레이션을 수행하여 AODV, DSR, SLAP과 지연, 패킷 전송률 등을 비교하여 평가하였다.