• 산업경영시스템학회지
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• 제13권22호
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• pp.87-98
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• 1990

The performance analysis and capacity planning of Service Control Point which is real time response system is studied. The system is modeled by multiclass open queueing network. The analytical method is used to solve the queueing network. The solution of the model has product form solution. The focus of this paper is to investigate the capacity of system under the restriction of response time. To get the reasonable capacities, nonlinear programming problem is formulated and is solved by GINO. And the simulation model using SLAM II is formulated.

• International Journal of Quality Innovation
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• 제2권1호
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• pp.30-49
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• 2001

This paper considers a recent environment in the manufacturing process in which data in large amounts can be obtained on-line in real-time. Under this environment an on-line real-time Statistical Process Control (SPC) scheme equipped with detection of a process change, change-point estimation, and recognition of the change pattern is proposed. The proposed SPC scheme is composed of a Cusum chart, filtering methods and Akaike Information Criterion (AIC). We examine the performance of this scheme by Monte Carlo simulation and show its usefulness.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.877-881
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• 2001

In this paper, a model is developed that can predict insulation performance of sound barrier systems under the action of multiple random point impact. The predicted results are compared with the measured results obtained by using APAMAT II. The results show the error due to the difference between experimental environment and theoretical assumptions. The model is needed to be improved to obtain better agreement between predicted and measured results.

• 제어로봇시스템학회논문지
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• 제20권9호
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• pp.957-963
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• 2014

This paper proposes a predictive control for an efficient human following robot using Kinect sensor. Especially, this research is focused on detecting of foot-end-point and foot-vector instead of human body which can be occluded easily by the obstacles. Recognition of the foot-end-point by the Kinect sensor is reliable since the two feet images can be utilized, which increases the detection possibility of the human motion. Depth image features and a decision tree have been utilized to estimate the foot end-point precisely. A tracking point average algorithm is also adopted in this research to estimate the location of foot accurately. Using the continuous locations of foot, the human motion trajectory is estimated to guide the mobile robot along a smooth path to the human. It is verified through the experiments that detecting foot-end-point is more reliable and efficient than detecting the human body. Finally, the tracking performance of the mobile robot is demonstrated with a human motion along an 'L' shape course.

• 대한전자공학회논문지SP
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• 제47권1호
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• pp.169-174
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• 2010

이 논문은 잡음환경에서 음성인식률 향상을 위한 끝점 검출 방법에 대해 소개한다. 제안된 방법은 엔트로피와 음성의 하모닉 검출을 이용해 음성 구간과 비음성 구간을 검출한다. 음성의 스펙트럴 에너지에 대한 엔트로피를 사용하여 끝점검출을 하게 되면 비교적 높은 SNR 환경(SNR 15dB)에서는 성능이 우수하나 잡음환경의 변화에 따라 음성과 비음성의 문턱값이 변화 하여 낮은 SNR환경(SNR 0dB)에서는 정확한 끝점 검출이 어렵다. 본 논문은 낮은 SNR 환경(0dB)에서도 정확한 끝점을 검출할 수 있도록 음성의 스펙트럴 엔트로피와 하모닉 성분을 검출하여 끝점을 검출하는 방법을 제안한다. 실험결과 기존의 엔트로피만을 이용한 방법보다 개선된 성능을 보였다.

• 상하수도학회지
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• 제22권6호
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• pp.697-704
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• 2008

Stormwater runoff from urban road area as non-point source has a tendency of including lots of pollutants at initial rain period. Recently, there are several cases of having installed treatment facilities for reducing pollution discharge from the impervious cover in urban area to prevent watershed environment from getting worse. The filtration type among non-point source treatment systems has been known as one of the most efficient system for treatment of non-point source pollutants. Therefore, various kinds of filter media such as expanded polypropylene(EPP), granular activated carbon, zeolite, perlite, illite, sand, gravel has been developed. This study was conducted to verify performance and hydraulic characteristics of filter media as measures for non-point source. The experiment was carried out to evaluate applicability and variation of 4 kind of most popular filter media(EPP, GAC, Zeolite, Perlite) in headloss with elapsed time and influent flow rate and to obtain data base that could be used to establish management plan for road runoff treatment. In experiment by tap water, it showed that EPP and perlite those are floatable materials showed stable operating performance and lower headloss than the others.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2012년도 제38회 춘계학술대회논문집
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• pp.416-423
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• 2012

액체추진제 공급시스템의 액체포집장치는 추진기관으로 기포가 유입되는 것을 방지하는데 사용한다. 액체포집장치는 차단막의 미세 구멍의 모세관 효과를 이용하여 추진기관에 순수 액체만을 공급한다. 기포점은 액체포집장치의 설계에서 가장 중요한 설계변수이다. 본 논문에서는 문헌조사를 통해 액체포집장치의 성능에 영향을 미치는 변수들을 식별하고 기포점 측정 시험 장치를 구성하였다.

• KIEAE Journal
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• 제17권2호
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• pp.5-12
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• 2017

Purpose: Under the purpose of presenting the adequate remodeling period for the improvement of thermal insulation performance of external walls in deteriorated buildings, the change in external wall and residential environment problem(dew condensation) due to aged deterioration after the apartments were constructed in Korea were analyzed. Method: Temperature Difference Ratio Outside(TDRo) and Heat Flow Meter(HFM) were used as measurement methods to evaluate the thermal insulation performance of deteriorated buildings. For TDR evaluation, thermo-graphic camera was used to measure and analyze the surface temperature of external wall. Also, dew condensation evaluation was analyzed using the Temperature Difference Ratio Inside(TDRi). Result: As a result of analyzing thermal performance through TDRo, the first decline point of thermal insulation performance began after 14-16 years have passed since construction was completed, and after 20 years have passed the decline point of thermal insulation performance reappeared. As a result of analyzing U-value with HFM measurement method, the decline rate of external wall's thermal insulation performance is lower than 2% in average at around 5 years after completion, and 8.7% in average at 10-15 years, and over 10.2% in average at 20 years.

• 대한안전경영과학회지
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• 제10권1호
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• pp.107-116
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• 2008

Nowadays, BSC presented by alpan is observed by many enterprises and is being operated gradually. BSC includes non-financial factor as well as financial factor in performance assessment and it is a tool that will be able to evaluate even strategy of long-term view. In point of performance management, BSC brings in relief importance on non-financial performance as well as financial performance and it shares with viewpoint of 4 things of financial viewpoint, customer viewpoint, internal process view point, learning and growth viewpoint. then these make an array with vision and strategy of organization by causal relationship, it presented necessity of performance control on organization as center on KPI of inner of each viewpoint. Thus, study on measures and control of management performance is progressed actively and is accomplishing much development. This study is aimed at calculation of weight that is able to reflect its importance about AHP on KPI of each viewpoint. The purpose of this study is to present desirable performance measurement model and to give a weight in consideration of working-level character.

• 마이크로전자및패키징학회지
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• 제17권4호
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• pp.73-76
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• 2010

A two-facet approach was used to investigate the parametric performance of functional high-speed DDR3 (Double Data Rate) DRAM (Dynamic Random Access Memory) die placed in different types of BGA (Ball Grid Array) packages: wire-bonded BGA (FBGA, Fine Ball Grid Array), flip-chip (FCBGA) and lead-bonded $microBGA^{(R)}$. In the first section, packaged live DDR3 die were tested using automatic test equipment using high-resolution shmoo plots. It was found that the best timing and voltage margin was obtained using the lead-bonded microBGA, followed by the wire-bonded FBGA with the FCBGA exhibiting the worst performance of the three types tested. In particular the flip-chip packaged devices exhibited reduced operating voltage margin. In the second part of this work a test system was designed and constructed to mimic the electrical environment of the data bus in a PC's CPU-Memory subsystem that used a single DIMM (Dual In Line Memory Module) socket in point-to-point and point-to-two-point configurations. The emulation system was used to examine signal integrity for system-level operation at speeds in excess of 6 Gb/pin/sec in order to assess the frequency extensibility of the signal-carrying path of the microBGA considered for future high-speed DRAM packaging. The analyzed signal path was driven from either end of the data bus by a GaAs laser driver capable of operation beyond 10 GHz. Eye diagrams were measured using a high speed sampling oscilloscope with a pulse generator providing a pseudo-random bit sequence stimulus for the laser drivers. The memory controller was emulated using a circuit implemented on a BGA interposer employing the laser driver while the active DRAM was modeled using the same type of laser driver mounted to the DIMM module. A custom silicon loading die was designed and fabricated and placed into the microBGA packages that were attached to an instrumented DIMM module. It was found that 6.6 Gb/sec/pin operation appears feasible in both point to point and point to two point configurations when the input capacitance is limited to 2pF.