• 동아시아경상학회지
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• 제10권2호
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• pp.31-42
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• 2022

Purpose - The main research goals by macroeconomic analysis is to assess the effectiveness of state regulation, the sustainability of development, and the financial stability of the state. Research design, Data, and methodology - The research were analyzed using the methods of multivariate statistics and application of the software package Stat graphics. The volume of data from the 1995 to the 2021 was analyzed by Russian Federation. The scale of research on Belarus: to be analyzed the amount of data from the 2015 by 2021, on Kazakhstan - from the 19941, on Kyrgyzstan - from the 2002, on Tajikistan - from the 2008, on Armenia - from the 2021, on Japan - since the 1970, on China - since the 1950, on South Korea - since the 1953. Result - The methods of multivariate statistics was demonstrated exact of result in forecasting of macroeconomic indicators. The most of tendency with the accurate results of are described using the second-degree polynomials. In the most research of country there are the macroeconomic proportion are broken. Conclusion - In the countries studied, the monetary aggregates have a significant growth rate. The shares with a substantial monetary stock and the speed of its growth are divided in the two groups: having placements in the real sectors of the economy and not having received the same result of development from the growth of the monetary stock.

• 한국정밀공학회지
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• 제21권4호
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• pp.39-47
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• 2004

In mold machining, there are many concave machining regions where chatter and tool deflection occur since MRR(material removal rate) increases as curvature increases even though cutting speed and depth of cut are constant. Boolean operation between stock and tool model is widely used to compute MRR in NC milling simulation. In finish cutting, the side step is reduced to about 0.3mm and tool path length is sometimes over loom, so Boolean operation takes long computation time and includes much error if the resolution of stock and tool model is larger than the side step. In this paper, curvature of CL (cutter location) surface and side step of tool path is used to compute the feedrate for constant MRR machining. The data structure of CL surface is Z-map generated from NC tool path. The algorithm to get local curvature from discrete data was developed and applied to compute local curvature of CL surface. The side step of tool path was computed by point density map which includes cutter location point density at each grid element. The feedrate computed from curvature and side step is inserted to new tool path to regulate MRR. The resultants were applied to feedrate optimization system which generates new tool path with feedrate from NC codes for finish cutting. The system was applied to the machining of speaker and cellular phone mold. The finishing time was reduced to 12.6%, tool wear was reduced from 2mm to 1.1mm and chatter marks and over cut on corner were reduced, compared to the machining by constant feedrate. The machining time was shorter to 17% and surface quality and tool was also better than the conventional federate regulation using curvature of the tool path.

• 한국산학기술학회논문지
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• 제16권3호
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• pp.1677-1683
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• 2015

배출가스 규제강화에 대응하기 위해 전자제어 디젤엔진의 적용으로 연료 분사량과 연료 분사시기를 정밀하게 제어하여 연료소비율과 출력 향상 및 소음과 진동이 감소되었다. 전자제어 디젤엔진 시스템의 성능을 유지하기 위해서는 연료압력을 정밀하게 제어하는 중요한 부품이 연료압력 레귤레이터이며 제어불량이 발생할 경우 연료압력이 정밀하게 제어되지 않아 시동불량, 시동지연, 가속불량, 엔진부조 등 이상 현상이 초래된다. 본 실험에서는 연료압력 레귤레이터의 고장에 따른 성능변화를 고찰하기 위하여 연료압력 레귤레이터 제어율에 변화를 주어 연료압력, 회수된 연료유량과 엔진회전수에 미치는 영향을 실험적으로 고찰하였다. 실험결과, 연료압력 레귤레이터의 제어율이 기준에서 4-6% 정도 낮아지면 엔진회전수, 회수되는 연료유량의 변화가 크게 나타났으며 이 때 이상현상이 발생함을 확인하였다. 또한 이를 통하여 연료압력 레귤레이터의 고장 유무을 판단할 수 있다.

• 전자공학회논문지
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• 제53권9호
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• pp.67-74
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• 2016

본 논문에서는 다중 직교 부반송파 변조 기반의 새로운 UHF RFID 통신 시스템을 제안한다. 태그 송신-리더 수신 통신에서는 4 부반송파를 이용하여 1.6 Mbps까지 전송속도를 향상시킬 수 있다. 회로의 복잡도 증가를 억제하면서도 전송 속도를 향상시키기 위해서, 태그는 부반송파로서 구형파를 사용하고 각 부반송파는 각각의 부하변조기를 이용한다. 다중 직교 부반송파 기반의 변조 방식을 사용하였기 때문에 제안한 통신 방식은 기존의 UHF 대역 RFID 규격을 만족한다. 리더는 OFDM 복조기를 사용한다. 태그가 리더의 CW 반송파를 역산란하므로 리더 복조기에는 반송파 주파수 오프셋 보정회로는 필요하지 않다. 실험에서는 개발 시스템은 10.8 dB의 잡음 밀도당 비트에너지 비에서 10-5의 비트오율 성능을 가짐을 보인다.

• 현장농수산연구지
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• 제26권1호
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• pp.16-21
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• 2024

본 연구는 해마다 수입을 많이 해오고 있는 콩과 녹비작물 종자의 발아율을 높이기 위해서 연구되었다. 열탕처리는 콩과 식물에서처럼 두꺼운 종피로 인해 휴면상태에 빠지는 종자의 발아율 향상 및 발아속도 증진을 위해 사용하는 방법이다. 클로버류와 자운영은 열탕처리가 무처리 보다 발아일수와 발아속도가 다소 높았다. 하지만 발아율과 발아세의 경우 무처리가 열탕처리보다 다소 높았지만 유의미한 차이를 보이지 않아 열탕처리가 발아율에 효과가 있다고 판단되지는 않는다. 네마장황의 경우 발아율과 발아속도를 높이는데 있어서는 염수선 처리가 가장 효과가 좋았고, 열탕처리는 초기 발아속도를 높일수는 있지만 발아율을 높이는데는 적합하지 않은 것으로 보였다. 헤어리베치의 경우 수입산 헤어리베치와 국내산 헤어리베치(토익과 청풍보라)에서 열탕처리와 염수선처리는 발아율에는 효과가 없었으나 발아세, 발아속도, 평균발아일수에는 다소 효과가 있다고 판단된다. 따라서 콩과 녹비작물과 같이 두꺼운 종피로 인하여 휴면상태에 빠지는 종자의 경우 발아율 향상과 발아속도를 향상시키기 위해 열탕처리나 염수선처리를 하는 것이 좋을것이라 사료된다.

• Journal of Nutrition and Health
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• 제39권8호
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• pp.742-747
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• 2006

This study was performed to investigate the lipolytic effects of Portulaca oleracea L. extract in 3T3-L1 adipocytes. The Portulaca oleracea L. was extracted with extrusion method using twin-screw extruder under $58{\sim}60rpm$ screw speed, $4{\sim}5kg/hr$ feed rate, $140^{\circ}C$ extrusion temperature. The lipolytic action of Portulaca oleracea L. extract was estimated by measuring the amount of glycerol and free fatty acids (FFA) released from 3T3-L1 adipocytes and by measuring the cellular lipid content in 3T3-L1 adipocytes. The hormone sensitive lipase (HSL) mRNA level was analyzed using quantitative real-time PCR. The Portulaca oleracea L. extract at 1 to $100{\mu}g/ml$ suppressed lipid accumulation. The release of glycerol and FFA into the medium, and the mRNA level of HSL were significantly increased by the addition of Portulaca oleracea L. extract at dose-dependent manner. In conclusion, the Portulaca oleracea L. extract was suggested to have the lipolytic effect through release of lipolytic products (FFA and glycerol) of triacylglyceride to the culture medium and suppression of lipid accumulation via up-regulation of HSL gene expression in 3T3-L1 adipocytes.

• Tribology and Lubricants
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• 제25권6호
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• pp.387-398
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• 2009

The operation condition of recently designed pistons for high power and high speed diesel engine become more severe due to the increment of combustion pressure and temperature. So, in order to overcome high temperature, the application of the mono-metal cast aluminum alloy piston featuring an enclosed cast-in open cooling gallery has increased. In this research, it is developed a PCJ (piston cooling jet) rig tester, described the test procedure and validated the performance of sample piston cooling gallery design. Then the test rig will be used for developing the design technology of piston cooling gallery. The test rig is composed with oil reservoir and pumping system, oil jet system, piston fixing and moving system, collecting oil measuring system, and data measuring and recording system. It will be measured collecting efficiencies under conditions of a few piston positions, oil jet pressures and oil viscosities for a piston cooling gallery. Furthermore, the PCJ rig tester will be used for the optimum design of the oil cooling gallery which being applied to increase the cooling efficiency of pistons in diesel engines satisfying the EURO V emission regulation and the more.

• Journal of Advanced Marine Engineering and Technology
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• 제36권4호
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• pp.423-429
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• 2012

밀러 사이클은 저배기 및 고효율 달성으로 Tier II 규제뿐만 아니라 $CO_2$ 저감을 동시에 달성할 수 있는 기술로 알려져 있다. 그러나 이를 위해서는 충분한 흡입공기량이 확보되어야 하며 흡기계통은 공기저항을 최소화할 수 있는 형상으로 개선되어야 한다. 본 연구에서 흡기계통 설계 및 사이클 해석에 활용하기 위한 기초 자료 확보를 위해 흡기밸브의 유량계수를 측정하였다. 유량계수 측정에는 정상유동장치를 이용하였다. 중속 박용기관에 사용되는 포핏 밸브를 대상으로 실험을 수행한 결과, 흡기밸브 유량계수는 밸브양정의 증가에 따라 약 0.62까지 지속적으로 증가하는 경향이며 행정/보어 비와는 무관한 흡기밸브 고유의 특성이 있음을 확인하였다.

• 한국환경과학회지
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• 제16권10호
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• pp.1179-1187
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• 2007

This paper represents the statistical characteristics of sources and receptors for road traffic noise in apartment complex. Also we suggested that the site-specific characteristics of vertical and horizontal distributions in the complex apartment have been derived using a different analysis for evaluating levels of Leq1h by the apartment floor at a given distance from a road in terms of the flow rate, the mean speed of the traffic, and the percentage of the type vehicles in the day and night periods. As a result, the contribution orders of traffic quantity by the type of vehicles showed as followed: light vehicle>medium vehicle>heavy vehicle>motorcycle. Especially, the mixing ratio of entering the road on the heavy vehicle in the daytime was two times higher than that of in the night. The speed in all types of vehicle is in the range of 41 and 81 km/hr and noise level was not significantly different in day and night-time. The sources of road traffic noise had different variations and uncertainties using a random variable and probability distribution. The sound distribution to receptors by the apartment floor showed S curve between 1st floor and $15^{th}$ floor With the normality test, the normal distributions using Anderson-Darling Test followed $1^{st},\;3^{th},\;13^{th}$ and $15^{th}$, floor in the daytime and all floors except $7^{th}$ floor in the night (p>0.05). And also, the value of the pearson correlation coefficient (r) obtained in this study have significantly different at the range of floor. In conclusion, the results suggested that the distribution characteristics of levels of $Leq_{1h}$ on the sources and receptors of road traffic noise in apartment complex must be improved and developed on the guideline of regulation of road traffic noise.

• 한국도로학회논문집
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• 제16권1호
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• pp.11-19
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• 2014

PURPOSES : The purpose of this article is to investigate the predicted life of jointed concrete pavement (JCP) with two variables effecting on axle load spectra (ALS). The first variable is different data acquisition methods whether using high-speed weigh-in-motion (HS-WIM) or not and the other one is spectra distribution due to overweight enforcement on main-lane of expressway using HS-WIM. METHODS : Three sets of ALS had been collected i) ALS provided by Korea Pavement Research Program (KPRP), which had been obtained without using HS-WIM ii) ALS collected by HS-WIM before the enforcement at Kimcheon and Seonsan site iii) ALS collected after the enforcement at the same sites. And all ALS had been classified into twelve vehicle classes and four axle types to compare each other. Among the vehicle classes, class 6, 7, 10 and 12 were selected as the major target for comparing each ALS because these were considered as the primary trucks with a high rate of overweight loading. In order to analyze the performance of JCP based on pavement life, fatigue crack and International Roughness Index (IRI) were predicted using road pavement design program developed by KPRP and each ALS with same annual average daily traffic (AADT) was applied to design slab thickness. RESULTS : Comparison ALS of KPRP with those of HS-WIM shows that the ALS of KPRP has a low percentage of heavy spectra such as 6~9 tonnes for single axle, 18~21 tonnes for tandem axle and 27~30 tonnes for tridem axle than other two ALS of HS-WIM in most vehicle classes and axle types. It means that ALS of KPRP was underestimated. And after the enforcement, percentage of heavy spectra close to 10 tonnes per an axle are lowered than before the enforcement by the effect of overweight enforcement because the spectra are related to overweight regulation. Prediction results of pavement life for each ALS present that the ALS of HS-WIM collected before the enforcement makes the pavement life short more than others. On the other hand, the ALS of KPRP causes the longest life under same thickness of slab. Thus, it is possible that actual performance life of JCP under the traffic like ALS of HS-WIM could be short than predicted life if the pavement was designed based on ALS provided by KPRP. CONCLUSIONS : It is necessary to choose more reliable and practical ALS when designing JCP because ALS can be fairly affected by acquisition methods. In addition, it is important to extend performance life of the pavement in service by controlling traffic load such as overweight enforcement.