• 생물환경조절학회지
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• 제2권1호
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• pp.27-36
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• 1993

Carbon dioxide enrichment for greenhouse crops has generally been a standard commercial practice for many years. Vegetable crops such as tomato, cucumber, and lettuce respond positively to the $CO_2$ enrichment. But improper $CO_2$ enrichment leads to physiological damage and economical loss. This study was carried out to develop a $CO_2$ concentration control algorithm considering growth stage and efficiency. The measurand was $CO_2$ consumption rate and top fresh weight that represents growth stage. The weight of top fresh lettuce as a whole in the tray was measured through a non-destructive method. The demand in $CO_2$ concentration according to growth stage was investigated. The results are summarized as follows. 1. The $CO_2$ consumption rate could be measured within the error of $\pm$ 15.4mg$CO_2$/hr in the range of $CO_2$ concentration of 500-1500ppm. 2. The weight of top fresh lettuce could be measured within the error $\pm$ 4.3g in the range of 0-1400g. 3. The $CO_2$ control model developed could determine an economical $CO_2$ supply rate considering $CO_2$ consumption rate and leakage rate. 4. The $CO_2$ control algorithm based on the control model was composed of feedforward control for maintaining a stable $CO_2$ concentration level, and feedback control with $CO_2$ consumption rate and top fresh weight for adapting to the change in $CO_2$ demand by growth stage. 5. For the performance test with the developed control algorithm on lettuce the decrease in $CO_2$ supply rate was obtained without a significant decrease in top fresh weight.

• 대한인간공학회지
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• 제29권2호
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• pp.197-202
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• 2010

The purpose of this study was to examine differences between male and female in heart rate due to 93% oxygen administration of the three levels (1L/min, 3L/min, and 5L/min). Ten healthy male (25.0$\pm$1.8years) and ten female (23.7$\pm$1.9years) college students were selected as the subjects for this study. The experiment consisted of three runs, i.e., the three levels of 93% oxygen administration, respectively. The each run consisted of three phases, i.e., Rest 1 (5min), Hyperoxia (10min), and Rest 2 (5min). Heart rate was measured throughout the three phases. Heart rate was decreased during hyperoxia compared to Rest 1 and 2. By increasing the supply rate of highly concentrated oxygen, ${\Delta}1$ (decreasing rate of heart rate during hyperoxia compared to Rest 1) was increased. And ${\Delta}2$ (decreasing rate of heart rate during hyperoxia compared to Rest 2) of male was lower than female, regardless of supply rate.

• KDI Journal of Economic Policy
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• 제44권3호
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• pp.1-26
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• 2022

This paper analyzes the effects of the cut in the legal maximum interest rate (from 27.4% to 24%) that occurred in February of 2018 on loan interest rates, the default rates, and the loan approval rate of borrowers in the non-banking sector. We use the difference-in-difference identification strategy to estimate the effect of the cut in the legal maximum interest rate using micro-level data from a major credit-rating company. The legal maximum rate cut significantly lowers the loan interest rate and default rate of low-credit borrowers (i.e., high-credit-risk borrowers) in the non-banking sector. However, this effect is limited to borrowers who have not been excluded from the market despite the legal maximum interest rate cut. The loan approval rate of low-credit borrowers decreased significantly after the legal maximum interest rate cut. Meanwhile, the loan approval rate of high-credit and medium-credit (i.e., low credit risk and medium credit risk) borrowers increased. This implies that financial institutions in the non-banking sector should reduce the loan supply to low-credit borrowers who are no longer profitable while increasing the loan supply to high- and medium-credit borrowers.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.514-517
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• 1996

Zero current switching(ZCS) series resonant converter is used to control laser power density in a pulsed Nd:YAG laser power supply. The high power and high repetition rate paused Nd:YAG laser is designed and fabricated to control current pulse width and pulse repetition rate in the double elliptical laser oscillator. In order to find out operational characteristics of pulsed Nd:YAG laser, the electrical properties of driving power supply and laser output power are investigated and experimented by changing of the current pulse width from 200uS to 350uS(step 50uS) and pulse repetition rate range of 500pps(pulse per second) to 1150pps. From that result, we obtaind maximum efficiency of 1.83% and maximum laser output or 220W at the condition of 350 uS and 1150pps with one Nd:YAG rod), and obtained that of more than 400W with two laser head connecting series.

• The Journal of Asian Finance, Economics and Business
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• 제8권1호
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• pp.93-102
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• 2021

This study aims is to determine the factors that influence Indonesian rubber export supply based on the export destination countries. Indonesian rubber export supply is thought to be influenced by the variables like the volume of Indonesia rubber exports, the price of Indonesian natural rubber, the volume of domestic rubber production, the export volume of the previous period, the rupiah exchange rate against US$, the interest rate and real Gross Domestic Product (GDP). The data used is the annual time series from 1995-2015 based on export countries encompassing the United States, China, and Japan. Multiple linear regression with the Ordinary Least Square (OLS) method is applied to analyse the data. The results showed that the volume of Indonesian rubber exports to China is not influenced by domestic natural rubber prices and the Rupiah exchange rate against the Chinese Yuan. The volume of Indonesian rubber exports to Japan is influenced by the volume of domestic rubber production. The volume of Indonesian rubber exports to the three destination countries is influenced by the volume of domestic rubber production, interest rate, and real GDP.

• The Journal of Asian Finance, Economics and Business
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• 제9권9호
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• pp.39-47
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• 2022

This study explored the effectiveness of the measures taken by the Jordanian Central Bank embedded in its monetary policy in encouraging banks to support investment. It aimed to explore the impact of this monetary policy on supporting credit-related decisions and the monetary policies that aim to support investment in Jordan. The targeted tools of the monetary policy are: (Overnight Deposit Window Rate, money supply, and exports). The researchers carried out an analysis to measure the effectiveness of the monetary policy in fostering investment in Jordan during the period 1992-2020. They carried out the time series analysis. They explored the stationarity of the time series. They used the ARDL model. It was found that the Overnight Deposit Window Rate has a negative significant effect on the gross fixed capital formation. It was found that the money supply has a positive insignificant effect on gross fixed capital formation. The researcher recommends using Overnight Deposit Window Rate in a manner that is consistent with the intended investment-related goals.

• 한국컴퓨터정보학회논문지
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• 제4권4호
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• pp.140-147
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• 1999

ABR(Available Bit Rate) 서비스는 ATM(Asynchronous Transfer Mode)망에서 guranteed 서비스에 의해 사용되고 있지 않는 여분의망 자원을 보다 효율적으로 사용키 위해 최대 전송률이 높고 burst한 특성을 지닌 응용들을 best effort 형태로 지원해주는 서비스이다. ATM 망에서 ABR 흐름제어를 위해 사용되는 스위치는 폭주상태 정보만 제공하는 EFCI(Explicit Forward Congestion Indication)스위치와 fair rate를 source에게 제공하는 ER(Explicit Rate)스위치로 구분할 수 있다. 본 논문에서는 ATM망에서 ABR 서비스를 위하여 EFCI 스위치와 ER 스위치가 ATM망에서 혼용되어 사용될 경우 ABR트래픽을 효율적으로 처리하기 위한 스위칭운용기술에 대해서 분석하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2008년도 추계 학술논문 발표대회
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• pp.141-145
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• 2008

Because of world financial crisis, The Korea domestic construction industry has been damaged hugely on material supplying work. A current domestic material supply system can't react properly on a great rise of foreign exchange rate and raw material price, so the system has a problem which is not properly supplying material. To solve this problem, a more innovative material supply work system is seriously needed than ever. So this study wants to improve material supply system for supplying material right time, right place through applying a web-based system. Applying this, overall process of material-supply-work can be done on a web-based system for immediately understanding change of ordering and warehousing by material-supply-schedule to a domestic construction field.

• 한국컴퓨터산업학회논문지
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• 제2권3호
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• pp.357-362
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• 2001

기존의 레이저통신용 스위칭 방식은 변압기 2차측에 정류부 및 평활용 콘덴서가 필수적으로 포함되어 있으며, 이렇게 얻어진 직류전압의 후단부를 스위칭 하게 되므로 시스템장치가 복잡하다. 또한 스위칭에 의한 손실이 크고, 펄스반복율(pulse repetition rate)이 증가할수록 콘덴서에 저장된 에너지가 램프로 충분히 전달되지 못하여 레이저 출력 효율이 저감되는 단점이 있다. 본 연구에서는 스위칭에 의한 손실을 줄여 레이저의 출력 효율을 개선하고자 교류전압의 영점(ZERO)을 ZCC(zero cross control)방식으로 검출하여 변압기 2차측 교류전압의 영점에서 SCR을 턴-온(turn-on)시키는 레이저 시스템을 설계 및 제작하였다. 그 결과 기존의 평활용 콘덴서와 정류부를 사용한 레이저 시스템보다 펄스반복울이 10[pps]씩 증가할수록 레이저 출력 효율 약 3.5$\%$씩 증가하여 60pps에서는 약 25$\%$까지 상승하였다.

• 상하수도학회지
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• 제37권5호
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• pp.281-288
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• 2023

This study was performed to evaluate the pollutants removal characteristics of two types of RBFs(Riverbank filtration, Riverbed filtration) intake facilities installed in Nakdong River and in Hwang River respectively. The capacity of each RBF is 45,000 m³/d for riverbank filtration intake facility and 3,500 m³/d for riverbed filtration intake facility. According to data collected in the riverbank filtration site, removal rate of each pollutant was about BOD(Biochemical Oxygen Demand) 52%, TOC(Total Organic Carbon) 57%, SS(Suspended Solids) 44%, Total coliforms 99% correspondingly. Furthermore, Microcystins(-LR,-YR,-RR) were not found in riverbank filtered water compared to surface water in Nakdong River. DOC(Dissolved Organic Carbon) and Humics which are precursors of disinfection byproduct were also reported to be removed about 59% for DOC, 65% for Humics. Based on data analysis in riverbed filtration site in Hwang River, removal rate of each contaminant reaches to BOD 33.3%, TOC 38.5%, SS 38.9%, DOC 22.2%, UV254 21.2%, Total coliforms 73.8% respectively. Additionally, microplastics were also inspected that there was no obvious removal rate in riverbed filtered water compared to surface water in Hwang River.