• Journal of the military operations research society of Korea
• /
• v.36 no.2
• /
• pp.85-106
• /
• 2010

Recently, government is endeavoring for Defense Ministry unit's efficiency improvement according as requires low cost, high effectiveness continuously about public sector. But, by real condition that measuring analysis about logistical corps'(LOG) efficient operation is not, this study was done to present method to estimate efficient management availability of logistical corps(LOG). Presents choosing variable that is suitable in Quartermaster Corps' efficiency estimation for this through existing virtue study investigation, and takes advantage of DEA (Data Envelopment Analysis) technique that divert in public sector efficiency measurement, I wish to present plan for inefficient organization's efficiency improvement after evaluate efficiency to Quartermaster Corps.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.431-432
• /
• 2008

HIT Solar Cell은 단결정 실리콘 웨이퍼가 초박막 amorphos 실리콘 층으로 싸여있는 구조이다. HIT Solar Cell에서 amorphos 실리콘의 두께와 도핑 농도는 태양전지의 효율을 결정하는 매우 중요한 요인이다. 본 논문에서는 높은 효율을 갖는 태양전지 설계를 위해 AFORS HET 프로그램을 이용하여 TCO_a-Si:H(p)_a-Si:H(i)_c-Si(n)_Al 구조를 설계했다. 후에 a-Si:H(p)의 두께와 a-Si:H(i) 의 두께를 가변하며 효율을 측정하였고, p-i-n 구조에서 n+ 층을 추가함에 따라 변하는 효율을 측정하였다. 최적화 한 결과 $V_{oc}$ = 693mV, $J_{sc}$ = 3891mA/$cm^{-2}$, FF = 8363%, $E_{ff}$ = 22.55% 의 고효율을 얻었다.

• The Korean Journal of Financial Management
• /
• v.19 no.1
• /
• pp.133-151
• /
• 2002

본 연구는 Malmquist지수를 이용하여 1997년 외환위기 때부터 2000년까지 국내은행의 생산성 변화를 순수기술효율성, 규모효율성 및 기술진보의 변화로 구분하여 측정함과 동시에 서울소재은행과 지방은행간의 생산성을 비교하였다. 1997년과 2000년간의 순수기술효율성의 변화는 감소하였지만, 규모효율성과 기술진보의 변화가 순수기술효율성의 하락 부분을 상쇄한 결과로 2000년에는 1997년의 생산성 수준을 회복하였다는 것을 확인하였다. $1997{\sim}2000$년의 서울소재 은행과 지방은행간을 비교한 결과에 의하면 서울소재은행의 생산성이 높게 나타났다. 두 집단간에 이러한 차이는 규모효율성으로부터 기인하였으며, 기술혁신을 의미하는 기술진보의 변화에는 두 집단간에 차이가 없었다. 특히 지방은행의 생산성은 2000년에도 1997년도 수준을 회복하지 못하고 있다.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.6 no.2
• /
• pp.164-172
• /
• 2001

This paper describes common MPPT(Maximum Power Point Tracking) control algorithm; Constant Voltage Control, P&O(Perturbation and Observation), IncCond(Incremental Conductance), and investigated it\`s efficiency. Though simulation and efficiency evaluation, the steady/transient states characteristics and efficiency of control algorithms are analyzed respectively. Also, two-mode MPPT control to improve on the existing control algorithm. Moreover, is proposed for high efficiency this paper suggests a topology for MPPT measuring efficiency and a method of examination.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.2
• /
• pp.386-391
• /
• 2021

Turbocharging is becoming a key technology for both diesel and gasoline engines. Regarding gasoline engines, turbocharging can help reduce carbon dioxide (CO2) emissions when used in conjunction with other technologies. This paper presents measurements of the turbine efficiency of pulsating flow in a twin-scroll turbocharger for gasoline engines. A cold gas test bench with a pulse generator was manufactured. The turbine efficiencies were calculated using the measured data of the instantaneous pressure and temperature of the inlet and exit of the turbine. The measurements were carried out at turbine speeds from 60,000 to 100,000 rpm under a pulsating flow of 25.0 Hz and 33.0 Hz. The turbine efficiencies ranged from 0.517 to 0.544. At the pulse frequency, 33.3 Hz, the variations in efficiency were 7.7% and 2.6% at turbine speeds of 60,000 rpm and 100,000 rpm, respectively. The turbine efficiency of the pulsating flow compared to those of steady flow was 7.0% and 3.0% lower at a turbine speed of 60,000 rpm and 100,000 rpm, respectively. The pulsating flow deteriorated the turbine efficiency, but the effects of pulsating flow decreased with increasing turbine speed.

• Electronics and Telecommunications Trends
• /
• v.16 no.5 s.71
• /
• pp.33-45
• /
• 2001

원활한 인터넷 서비스를 제공하기 위해서는 인터넷 트래픽을 효율적으로 관리할 수 있어야 하며, 이를 위해 가장 먼저 해야 할 것은 인터넷 트래픽을 측정하는 것이다. 인터넷 트래픽의 측정은 수동적인 측정과 능동적인 측정으로 분류된다. 수동적인 측정은 라우터나 ATM 스위치를 통해 흘러 다니는 트래픽 종류와 트래픽 양을 측정하여 측정네트워크의 트래픽 특성을 파악하는 것이고, 능동적인 측정은 측정네트워크 종단에 위치한 두 호스트 사이에 측정패킷을 투입하여 측정네트워크의 상태를 파악하는 것이다. 본 고는 현재 알려진 인터넷 트래픽 측정 방법과 현재 구현된 측정 시스템을 소개한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• v.9 no.2
• /
• pp.689-692
• /
• 2005

Bioelectrical Impedance Analysis(BIA) can measure body water amount and then body fat mass. Locate 4 electrode in palm to measure efficiently and flow current(50kHz, 800uA) in body for measuring voltage and capacitance. And proposed method to measure body fat with hight, weight, age and distinction of sex.

• 전기의세계
• /
• v.31 no.3
• /
• pp.187-190
• /
• 1982

발전효율은 증기발생용 수질 보일러의 구조 및 재질 등 여러가지가 있겠으나 그중 연료의 연소효율이 가장 중요하여 이것과 관련한 성상 및 연료현상에 대하여 기술하고 또한 국내에서는 이를 성능시험에 대한 제도적 장치 및 기법이 확립되어 있지 않아 성능 기준의 판정이 곤란한 실정이므로 측정 방법도 간단히 부연하였다.

• Membrane Journal
• /
• v.9 no.2
• /
• pp.132-139
• /
• 1999

Solid scintillation proximity membranes were prepared for measuring the amount of radioactivity in laboratories contaminated by the radionuclide of $^3H$-cortisol. The membranes, consisting of polysulfone as a polymer matrix and cerium activated yttrium silicate as a fluor, were used to monitor the amount of radioactivity without the aid of a scintillation cocktail required for the conventional wipe test. The test results of the cocktail-free wipe test showed that the prepared membranes were efficient to monitor radionuclide-contaminated areas with the good counting ability as well as with the decrease of overall production of radioactive waste. On the other hand, solvent treatment of the prepared membranes could induce a significant variation of membrane morphology, but the counting efficiency of the solvent-treated membranes was not improved than that of the untreated one.

• Journal of Korea Port Economic Association
• /
• v.24 no.4
• /
• pp.25-46
• /
• 2008

By using data envelopment analysis(DEA) this research measures the efficiency of Korea's five seaports and their Malmquist productivity from 1997 to 2006. Under the assumption of CRS(constant returns to scale) and VRS(various returns to scale), seaports' rankings of efficiency are measured. Busan port is confirmed as a best-performed port in the various measurements. Important finding facts are as follows. 1)Busan, lncheon and Ulsan seaports are efficient ports under the assumption of CRS and VRS. 2)Gwangyang port shows 4.3% lower efficiency level compared with efficient ports. 3)Pohang port shows 27.3% lower efficiency level compared with efficient ports. 4)Average total factor productivity of Korea's five ports has been lower at the rate of 3.1% during the period from 1997 to 2006. Main policy implications are 1)Busan port is more efficient than Gwangyang port, which reflects the difference of economic activities between two regional econmies. 2)During the period 1997-2006, Korea's five largest ports has experienced lower efficiency levels in the first half period because of the 1997 Korean Financial Crisis, but higher efficiency levels in the second half period because of economic recovery. In future research the more and better data will be expected to improve the understanding of Korean seaports' efficiency characteristics.