• The KIPS Transactions:PartA
• /
• v.12A no.5 s.95
• /
• pp.427-432
• /
• 2005

I studied about existent load distribution algorithms and the WLC(Weighted Least Connection) algerian that is using much at present to distribute the connection request of users to real servers efficiently in web cluster system. The efficiency of web cluster system is fallen by load imbalance between servers, because there is problem In inaccurate load status measuring of servers and measuring timing at these load distribution algorithms. In this paper, I suggest an algorithm that distributes load base on various load state of servers by real time using broadcasting RPC(Remote Procedure Call) when a user requests connection, and implement a prototype and experiment its performance. The experiment result shows that load imbalance phenomenon between reai sowers was improved greatly than existing method, and performance of web cluster system was improved by efficiency that response time is shortened.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.4
• /
• pp.996-1004
• /
• 2013

In this paper, we propose two clustering schemes to prolong lifetime by improving unbalance of energy consumption among sensor nodes in wireless sensor networks. The first proposed scheme make up clusters according to density of sensor nodes in initial stage of wireless sensor networks for reducing energy consumption of wireless sensor networks. After the initial stage, a cluster header is selected by a relay scheme that determines a cluster header of next round among cluster members. by estimating of energy consumption of cluster members for improving unbalance of energy consumption among cluster members.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.8A
• /
• pp.741-747
• /
• 2011

Matrix Pencil method is one of the promising method to estimate DOA in non-stationary, multi-path coherent environment. Not only the Matrix Pencil Method offers better resolution than the conventional approach using covariance matrix, but also it is computationally very efficient. In this paper, we presented an effect of unbalanced data weighting in the formulation of the Matrix Pencil method. A new formulation has been suggested to mitigate the effect of unbalanced data weighting. Numerical simulation demonstrated that the proposed method can successfully eliminate the problem of unbalanced data weighting.

• Journal of Korean Ophthalmic Optics Society
• /
• v.12 no.4
• /
• pp.9-14
• /
• 2007

We have studied the problems associated with increasing number of ophthalmic optics students every year. The main problems are surplus supply of the optometrist and poor working condition. Thus all parties concerned who aim to solve the numerical unbalance of optometrist must have the common policy in sight. And we have to make a long-term plan and permanent organization for medical technician to establish supply and demand of medical technician with exact policy. To solve this unbalance of optometrist numbers, we have to establish an exact job category, reform the specialized education course, estimate the practical technique of national licensing examination for Korean optometrist, and innovate the contents and methods of reeducation.

• Journal of Biosystems Engineering
• /
• v.11 no.2
• /
• pp.4-13
• /
• 1986

뿌리작물(作物)을 수확(收穫)하기 위(爲)하여 진동(振動)을 이용(利用)한 4절(節)링크로 구성(構成)되는 시작기(試作機)를 설계(設計), 제작(製作) 및 실험을 수행(遂行)하였다. 수확기(收穫機)의 작동중(作動中) 발생(發生)하는 불균형력(不均衡力)을 상쇄(相殺)시키기 위(爲)한 힘의 평형장치(平衡裝置)를 설계(設計)하기 위(爲)하여 각(各) 요소(要素)의 가속도(加速度) 및 동력학적(動力學的)인 힘을 분석(分析)하였고, 진동기구(振動機構)에 의(依)하여 발생(發生)되는 이론적(理論的)인 토크와 측정(測定)된 토크를 비교분석(比較分析)하였다. 설계(設計)된 힘의 평형장치(平衡裝置)는 불균형력(不均衡力)의 대부분(大部分)을 상쇄(相殺)시켜주고, 이론적(理論的)인 토크는 실측(實測)토크의 변화경향(變化傾向)과 잘 일치(一致)하였다.

• Journal of Power System Engineering
• /
• v.14 no.3
• /
• pp.13-18
• /
• 2010

HCCI engines fueled DME and natural gas have been studied on single-cylinder engine due to availability of reducing on $NO_X$ and PM simultaneously without deteriorating into high thermal efficiency, and thus it is clarified that higher maximum engine load is achieved as DME equivalence is smaller. In this study, combustion tests were accomplished on multi-cylinder engine for practical use of it. When minimum DME equivalence achieved maximum engine load on single-cylinder engine was applied to 4-cylinders engine, there was in unstable running condition that engine revolution fluctuated greatly and cyclically. It is the reason what misfire occurred intermittently with one the same as minimum DME equivalence on single-cylinder due to increase in energy for ignition at No. 1 cylinder with lower cylinder liner temperature. Maximum engine load was achieved by adopting EGR, though it decreased because of knocking at smaller engine load than single-cylinder due to increase in minimum DME equivalence.

• The Korean Journal of Applied Statistics
• /
• v.16 no.2
• /
• pp.195-202
• /
• 2003

Haplotype analysis in SNP is very useful for the study of complex genetic disease due to low cost and high efficiency comparing to individual analysis of each SNP, and is functionally important in biological view. But, the gametic phase of haplotypes is usually unknown in SNP group, and it is difficult to predict haplotype proportions. In this study, haplotype proportions were estimated using EM algorithm from diploid data of SNP group in solid tumor group and normal group. From these results, linkage disequilibrium among SNPs was analyzed.

• Communications for Statistical Applications and Methods
• /
• v.16 no.6
• /
• pp.903-913
• /
• 2009

In this paper, we suggested a modified revealed comparative advantage(RRCA) index for identifying regional strategic industries. The index is developed under the assumption that the concentration of industries in Korea is not based entirely on the comparative advantages. The Korean government has set up balanced development strategies since 2003 under the assumption too. The index is the ratio between the comparative advantage index and economic imbalance of the region. By the index, we selected strategic industries for 15 regions under the rule of 1) relative ratio of the index is more than 15%, 2) 1 to 3 regions for a industry according to the industry's output.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2004.10a
• /
• pp.54-57
• /
• 2004

Almost all injection molds have multi-cavity runner for mass production, which are designed with geometrically balanced runner system in order to minimize filling imbalance between cavity to cavity during processing. However, even though geometrically balanced runner is used, filling imbalances have sometimes been observed. These filling imbalances have historically been considered as result of uneven mold temperature and mold deflection, but it actually results from non-symmetrically shear, pressure, temperature distribution within melt material as it flows through the runner system. Filling imbalance could be decreased by modifying processing conditions that are related to shear, pressure, temperature such as injection rate, mold temperature, injection pressure, melt temperature. In this study, a series of experiment was conducted using Taguchi method to determine which processing condition influence as the primary cause of filling imbalance in geometrically balanced runner system. As a result of experiments, this paper could present an optimal processing condition to minimize variable that brings about filling imbalance geometrically balanced runner system

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.26 no.3
• /
• pp.323-330
• /
• 2016

This paper describes real-time unbalance moment compensation method for line of sight(LOS) stabilization control systems. The factors of system inertia, frictions and unbalance moment affect the control accuracy of drive systems that are equipped to on the move(OTM) platforms requiring LOS stabilization function. In case of the unbalance moment among those factors is continuously changed as variation of relative angle between gravity vector and drive torque vector. Then, consideration of the effect in real-time is very complicate. Therefore, its effect should be designed to be minimized, however, designing it almost zero is impossible in real condition. In other words, it is hard to achieve target performance overcoming stability issue of highly unbalanced systems. To solve these problems, this paper proposes calculation method of unbalance moment by using measured sensor data for LOS stabilization control and its use for control compensation. Also, kinematical converting process and control structure for compensation are explained. The effectiveness of the proposed method as variation of unbalance moment is verified under simulation circumstance modeled by assuming LOS control system with 2-axis gimbal structure.