• Title, Summary, Keyword: Performance index

Search Result 3,946, Processing Time 0.051 seconds

Performance Evaluation of Fixed-Grid File Index on NAND Flash Memory (NAND 플래쉬메모리에서 고정그리드화일 색인의 성능 평가)

  • Kim, Dong-Hyun
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.10 no.2
    • /
    • pp.275-282
    • /
    • 2015
  • Since a NAND-flash memory is able to keep data during electricity-off and has small cost to store data per bytes, it is widely used on hand-held devices. It is necessary to use an index in order to process mass data effectively on the flash memory. However, since the flash memory requires high cost for a write operation and does not support an overwrite operation, it is possible to reduce the performance of the index when the disk based index is exploited. In this paper, we implement the fixed grid file index and evaluate the performance of the index on various conditions. To do this, we measure the average processing time by the ratio of query operations and update operations. We also the compare the processing times of the flash memory with those of the magnetic disk.

A HYPOTHESIS TESTING PROCEDURE OF ASSESSMENT FOR THE LIFETIME PERFORMANCE INDEX UNDER A GENERAL CLASS OF INVERSE EXPONENTIATED DISTRIBUTIONS WITH PROGRESSIVE TYPE I INTERVAL CENSORING

  • KAYAL, TANMAY;TRIPATHI, YOGESH MANI;WU, SHU-FEI
    • Journal of applied mathematics & informatics
    • /
    • v.37 no.1_2
    • /
    • pp.105-121
    • /
    • 2019
  • One of the main objective of manufacturing industries is to assess the capability performance of different processes. In this paper, we use the lifetime performance index $C_L$ as a criterion to measure larger-the-better type quality characteristic for evaluating the product performance. The lifetimes of products are assumed to follow a general class of inverted exponentiated distributions. We use maximum likelihood estimator to estimate the lifetime performance index under the assumption that data are progressive type I interval censored. We also obtain asymptotic distribution of this estimator. Based on this estimator, a new hypothesis testing procedure is developed with respect to a given lower specification limit. Finally, two numerical examples are discussed in support of the proposed testing procedure.

A Analysis on the Effect of the Controller Design due to Performance Index (평가지표에 따른 제어기 설계 영향 분석)

  • Yoo, Hang-Youal;Lee, Jung-Kuk;Lee, Keum-Won;Lee, Jun-Mo
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
    • /
    • /
    • pp.90-94
    • /
    • 2004
  • Among various modern control theories, PID control has been well used for several decades. PID algorithms needs son tuning methods are used for selecting PID parameters. But in some cases various kinds of performance indices are used instead of well-known tuning rules, and so variable type of performance index must be tested so that controllers, output characteristics and disturbance rejection property meets some specifications. In this paper, linear conbinational type of performance using error signal, time, control input and robustness is used to the PID control of air conditioning system. By the 2 DOF PID parmeters minimizing perfromacne index, controllers, output characteristics and robustness properties are analyzed. Simulations are done with MATLAB m file and mdl files.

  • PDF

A Study on Quantitative Performance Index for Phase-Change Cooling Systems (상변화 냉각시스템의 정량적 성능지수 연구)

  • Jang, Myeong-Eon;Song, Hye-Eun
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.23 no.3
    • /
    • pp.237-245
    • /
    • 2020
  • In this paper, I introduce Phase-Change Cooling for thermal management of high power devices that can be applied to High Power Laser and Electric Propulsion Systems which are composed of multiple distributed superheat sources. Phase-Change Cooling can be good used to efficient cooling of their heat sources. Phase-Change Cooling has extremely high efficiency of two-phase heat transport by utilizing heat of vaporization, relatively low flow rates and reduced pumps power. And I suggest TPI(Thermal Performance Index) which is a quantitative performance index of Phase-Change Cooling for thermal management. I quantify the performance of Phase-Change Cooling by introducing TPI. I present the test results of TPI's changing refrigerant, heat sink and flow rate of the Phase-Change Cooling system through the experiments and analyze these results.

A Development of Risk Performance Index for Mega-project Performance Measurement in view of the integrated Cost/Schedule/Risk (비용/공정/위험 통합 관점에서 메가 프로젝트 성과측정을 위한 위험성과지수 개발)

  • Kim, Seon-Gyoo;Park, Kyoo-Young;Yu, Young-Jeong
    • Korean Journal of Construction Engineering and Management
    • /
    • v.10 no.1
    • /
    • pp.69-77
    • /
    • 2009
  • Recently, a research of the urban regeneration has been performed very actively. This is one of the efforts to resolve various social and economic problems coming from the existing deteriorated building and facilities by new urban development or redevelopment. However, an urban regeneration has a characteristic to be unable to ensure the project performance due to the exposed numerous risks coming from the various and complex stake-holders, and its mega sizes. This paper proposes the method of risk performance index in order to improve an efficiency of performance measurement expanding to the risk view point from the existing integrated cost/schedule performance measurement. A risk performance index is compatible with the existing EVMS, and can make the performance measurement in 3 dimensions of the integrated cost/schedule/risk with 18 sub-indexes and variables.

Effect of Toughness Index of Diamond Abrasives on Cutting Performance in Wire Sawing Process (와이어쏘 공정에서 다이아몬드 입자의 인성지수가 절단 성능에 미치는 영향)

  • Kim, Do-Yeon;Lee, Tae-Kyung;Kim, Hyoung-Jae
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.23 no.4_2
    • /
    • pp.675-682
    • /
    • 2020
  • Multi-wire sawing is the prominent technology employed to cut hard material ingots into wafers. This paper aimed to research the effect of diamond toughness index on the cutting performance of electroplated diamond wire. Three different toughness index of diamond abrasives were used to manufacture electroplated diamond wires. The cutting performance of electroplated diamond wire is verified through experiments, in which sapphire ingot are cut using single wire sawing machine. A single wire saw for constant load slicing is developed for the cutting performance evaluation of electroplated diamond wire. Choosing the cutting depth, total cutting depth, cutting force and wear of electroplated diamond wires as evaluation parameters, the performance of electroplated diamond wire is evaluated. The results of this study showed that there was a significant direct relationship between the toughness index of diamond abrasives and the cutting performance. Results demonstrated that diamond abrasive with a high toughness index showed higher cutting performance. However, all diamond abrasives showed similar cutting performance under low load conditions. The results of this paper are useful for the development of cutting large diameter ingots and cutting high hardness ingots at high speed.

An Index Structure for Main-memory Storage Systems using The Level Pre-fetching

  • Lee, Seok-Jae;Yoon, Jong-Hyun;Song, Seok-Il;Yoo, Jae-Soo
    • International Journal of Contents
    • /
    • v.3 no.1
    • /
    • pp.19-23
    • /
    • 2007
  • Recently, several main-memory index structures have been proposed to reduce the impact of secondary cache misses. In mainmemory storage systems, secondary cache misses have a substantial effect on the performance of index structures. However, recent studies still stiffer from secondary cache misses when visiting each level of index tree. In this paper, we propose a new index structure that minimizes the total amount of cache miss latency. The proposed index structure prefetched grandchildren of a current node. The basic structure of the proposed index structure is based on that of the CSB+-Tree, which uses the concept of a node group to increase fan-out. However, the insert algorithm of the proposed index structure significantly reduces the cost of a split. The superiority of our algorithm is shown through performance evaluation.

Structural damage detection using a damage probability index based on frequency response function and strain energy concept

  • Bagherahmadi, Seyed Ahdiye;Seyedpoor, Seyed Mohammad
    • Structural Engineering and Mechanics
    • /
    • v.67 no.4
    • /
    • pp.327-336
    • /
    • 2018
  • In this study, an efficient damage index is proposed to identify multiple damage cases in structural systems using the concepts of frequency response function (FRF) matrix and strain energy of a structure. The index is defined based on the change of strain energy of an element due to damage. For obtaining the strain energy stored in elements, the columnar coefficients of the FRF matrix is used. The new indicator is named here as frequency response function strain energy based index (FRFSEBI). In order to assess the performance of the proposed index for structural damage detection, some benchmark structures having a number of damage scenarios are considered. Numerical results demonstrate that the proposed index even with considering noise can accurately identify the actual location and approximate severity of the damage. In order to demonstrate the high efficiency of the proposed damage index, its performance is also compared with that of the flexibility strain energy based index (FSEBI) provided in the literature.

On a Performance Index of Automatic Steering System of Ships (선박 자동조타 시스템의 성능평가지수에 관한 고찰)

  • Kyoung-Ho Sohn;Gyoung-Woo Lee
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.32 no.4
    • /
    • pp.27-37
    • /
    • 1995
  • A performance index is very important and indispensable to the evaluation of automatic steering system of ships in open sea from the viewpoint of energy saving. In this paper, we derive the performance index of automatic steering system from the concept of energy loss of propulsive power. The index is found to consist of three terms, energy loss due to elongation of sailing distance, energy loss due to steering, and energy loss due to yawing motion. We also provide two kinds of calculation method on the performance index ; frequency response analysis and digital simulation. The numerical calculations are carried out for an ore carrier and a fishing boat by both methods. The frequency response analysis is found to be useful if the system is linear and the disturbance on ship is not large. If the system is nonlinear or the disturbance is excessive, the method of digital simulation has to be applied for the accurate evaluation of the performance index. Further investigations into the effects of nonlinear elements such as weather adjuster, power unit etc. on the performance index, will be dealt with in another paper.

  • PDF

A Structural Model of Management Goal Orientations and Preferred Goal Achievement Index in one Hospital Employees (한 종합병원 구성원의 경영목표 지향성의 구조적 모형과 선호 경영성과지표)

  • Park, Jae-Sung
    • Health Policy and Management
    • /
    • v.17 no.1
    • /
    • pp.50-74
    • /
    • 2007
  • The purpose of this study was to identify a determent of mastery approach goal and performance approach goal using a basic concept of goal orientations and goal setting theory, and to evaluate a preference of goal achievement index as a balance score card (BSC). The study model proposed had a adoptable level of goodness of fit index(.94) and root mean square residual(.08). The meditating variable, goal contribution, totally mediated the impact of goal commitment, Y-theory human behavior, and self-efficacy but organizational resource contribution for pursuing goal orientation. Moreover, goal contribution significantly determined mastery approach goal(p<.01) and performance approach goal(.05). In standardized effects, the most powerful antecedent of mastery approach goal and performance approach goal were in order of organizational resource contribution(.27/.28), goal contribution(.21/.17), self-efficacy(.07/.06), and Y -theory human behavior and goal commitment(.05/.05), respectively. Moreover, goal contribution had a more powerful impact on mastery approach goal(.21) rather than performance approach goal(.17). In the preference of BSC, all job types preferred learning and growth index in first. In the second preference, medical doctors and pharmacists chose financial results, nurses customer service, and office managers internal processes. Each job type reflected its' own preferred BSC index to that of the other job types. In comparing a preference of four BSC index of each own job type, it was statistically different at p<.001. In conclusion, one who emphasize organizational goal contribution in pursuing goal orientation has a more strong orientation toward mastery approach goal rather than performance approach goal. A hospital should overcome and harmonize the different preferences of four BSC index since the differences might cause organizational conflicts among job types with having each unique professional norm.