• Journal of Nutrition and Health
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• v.27 no.6
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• pp.537-551
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• 1994

The dietry effects of marine n-3, plant n-3 and plant n-6 fatty acid on serum lipids levels, liver phospholipid fatty acid composition in rat were investigated. Four groups of male Sprague-Dawley rats, 30 weeks old, were fed on one of 4 different experimental diets for 4 weeks. The diets were composed of 15% fat(w/w) of either concentrated EPA oil(20:5, n-3 : 65%), fish oil(20:5, n-3 : 19%, 22:6, n-3 : 18%), perilla oil(18:3, n-3 : 60%) or corn oil(18:2, n-6 : 49%). Blood was initially taken before experimental feeding and also taken after 2 weeks and 4 weeks feeding the diet respectively and then examined for the levels of serum lipids. Rats were sacrificed at 4 weeks after the diet for the analysis of liver phospholipid fatty acid. EPA feeding remarkably decreased the serum levels of triglyceride, total cholesterol, HDL-cholesterol and total phospholipid than any other oil feeding. Fish oil feeding decreased serum HDL-cholesterol level comparable to the effect of EPA feeding and decreased total cholesterol and phospholipid less than but close to the effect of EPA feeding. Perilla oil feeding did not change serum levels of triglyceride and phospholipid, but it decreased serum total cholesterol a lot and HDL-cholesterol a little. Corn oil feeding did not affect triglyceride and total cholesterol while it increased serum level of HDL-cholesterol and total phospholipid. Serum HDL-cholesterol level was increased only in corn oil group. But contrary to the result of serum total phospholipid, liver phospholipid level found to be higher in fish oil and EPA groups than in perilla oil and corn groups. The fatty acid composition of liver phospholipid, phosphatidylcholine(PC) and phosphatidyl ethanolamine(PE) turned out to be affected by dietary fatty acid. 18:2 of liver PC was the lowest in FO group following CO group. The ratio of 20:4/18:2 was lower in PO group than in EPA group in consequence of higher 18:2 and lower 20:4 in PO group and vise versa in EPA group. In the liver PC and PE, similar trends in the ratios of n-6/n-3 and 20:4/18 were found showing higher ratios with CO and EPA group over FO and PO group. EPA group showed the lowest level of 20:5 and lower level of 20:6 than group. Fish oil was more efficient than EPA oil and PO in lowering the ratio of n-6/n-3 in consequence of the highest 22:6, and the lowest 18:2 in liver phospholipid. But PO lowers the ratio or 20:4/18 more than FO. In conclusion, EPA oil was more effective in lowering serum lipids than FO and PO. Reviewing the dietary effect of fatty acid on eicosanoids composition in rats, it is considered that more possibility was with FO than PO in the effectiveness of atherosclerosis prevention and more with PO than with EPA oil. It was also found that FO showed more effective than EPA oil for atherosclerosis prevention. It was hardly found that CO had any effect on lowering serum lipids and on eicosanoids composition in liver phospholipid for the prevention of atherosclerosis.

• Membrane Journal
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• v.24 no.6
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• pp.453-462
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• 2014

Thin film composite (TFC) polyamide (PA) membranes were prepared on polyester (PET) nonwoven reinforced polysulfone supports for forward osmosis (FO) processes. PSF (polysulfone) supports were prepared via the phase inversion process from PSF casting solutions in dimethyl formamide (DMF) solvents (19 wt%) by using a PET nonwoven (thickness of $100{\mu}m$) as a mechanical reinforcing material for reverse osmosis (RO) membrane. The PSF support from 19 wt% of DMF/PSF casting solution showed sponge-like morphology and asymmetric internal structure. To reduce the internal concentration polarization in FO operation, thin ($20{\mu}m$ of thickness) nonwoven-supported PSF supports were prepared by using PSF/DMF casting solution (9~19 wt%). A desirable support structure with a highly porous sponge-like morphology were achieved from the thin nonwoven-supported PSF layer prepared with 9~12 wt% casting solution. A crosslinked aromatic polyamide layer was fabricated on top of each support to form a TFC PA membrane. The tested sample from 12 wt% of DMF/PSF casting solution presented outstanding FO performance, almost 5.5 times higher water flux (24.3 LMH) with low reverse salt flux (RDF, 1.5 GMH) compared to a thick nonwoven rainforced membrane (4.5 LMH of flux and 3.47 GMH of RSF). By reducing the thickness of the nonwoven and optimizing PSF concentration of casting solution, the morphology of the prepared membranes were changed from a dense structure to a porous sponge structure in the boundary area between nonwoven and PET support layer.

• Journal of the Microelectronics and Packaging Society
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• v.26 no.1
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• pp.29-33
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• 2019

With shrinking form factor and improving performance of electronic packages, high input/output (I/O) density is considered as an important factor. Fan out wafer-level packaging (FO-WLP) has been paid great attention as an alternative. However, FO-WLP is vulnerable to warpage during its manufacturing process. Minimizing warpage is essential for controlling production yield, and in turn, package reliability. While many studies investigated the effect of process and design parameters on warpage using finite element analysis, they did not take uncertainty into consideration. As parameters, including material properties, chip positions, have uncertainty from the point of manufacturing view, the uncertainty should be considered to reduce the gap between the results from the field and the finite element analysis. This paper focuses on the effect of uncertainty of Young's modulus of chip on fan-out wafer level packaging warpage using finite element analysis. It is assumed that Young's modulus of each chip follows the normal distribution. Simulation results show that the uncertainty of Young's modulus affects the maximum von Mises stress. As a result, it is necessary to control the uncertainty of Young's modulus of silicon chip since the maximum von Mises stress is a parameter related to the package reliability.

• Journal of Practical Agriculture & Fisheries Research
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• v.18 no.1
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• pp.71-78
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• 2016

The present study was performed to examine the high temperature adaptability with CO₂ treatment for tomato under the condition of greenhouse cultivation during summer season. The plants with the CO₂ concentration of 1000 ppm recorded higher scores in Fm/Fo and Fv/Fm but lower score in Fo than others through the measurement of chlorophyll fluorescence, which implicated that the plants with the CO₂ concentration of 1000 ppm had more adaptability to high temperature than the others. At the condition of the same air temperature as 30℃ and 40℃, the photosynthetic rate was increased with the increase of CO₂ concentration. When in the high air temperature state of 40℃, although the photosynthic rate was low in comparison with 30℃, its value was about 18.5umolm^-2s^-1 in case of 1000ppm. The higher concentration of CO₂ made the more activated anti-oxidation enzyme (superoxide dismutase and peroxidase) for the both cultivars as 'momotaro' and 'minichal'. The cultivar of 'minichal' performed the high temperature limit as 41℃ at the CO₂ condition of 500 ppm and 43℃ at the CO₂ condition of 1000 ppm through the estimation on the variation of chlorophyll fluorescence Fo by CO₂ concentrations.

• Research in Mathematical Education
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• v.4 no.2
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• pp.79-93
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• 2000

The purpose of this article is to introduce the gifted education of mathematics in Korea. We first discuss what is going on in Korea for mathematics education for gifted students. The curriculums for the institutes for gifted education are mentioned. Some focus of this article is proposing some teaching materials that are actively utilizing many basic concents of cryptography and super-string theory, along with careful use of calculators and computers. Many of the materials haven been designed with problem-posing approach on through invoking the cognitive conflict.

• Bulletin of the Korean Space Science Society
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• 2004.04a
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• pp.36-36
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• 2004

Ionospheric data from DGS-256 ionosonde operated by Radio Research Laboratory in Anyang archived during 1991-2002 was extracted and analyzed firstly in Korea. Daily, monthly and annual variations of the 12-year F2 layer critical frequency(foF2) are derived to investigate the statistical ionospheric characteristics during one complete solar cycle. Positive correlation between the mean values of 24-hourly monthly median foF2 and the monthly smoothed sunspot number(SSN) for the same period is found. (omitted)

• Journal of the Korean Institute of Telematics and Electronics C
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• v.34C no.11
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• pp.12-19
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• 1997

In this paper, we present a logic synthesis algorithm for low powr design fo combinational circuits. The proposed algorithm reduces power dissipation by eliminating unnecessary signal transitions. The proposed algorithm restructures a given circuit by using a kernel as prediction logic in a precomputation-based scheme such that switching activity of circuit can be minimized. Experimental results show that the system is efficient for low power design of combinational circuits.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.60-62
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• 2006

This paper presents an efficient frequency offset (FO) estimation algorithm for the orthogonal frequency division multiplexing (OFDM) based wireless local area networks (WLANS). The packet preamble imformation is utilized on the high rate WLAN standards adopted by the IEEE 802.11a. We present FO estimation schemes using diversity. In the simulation results, we prove that the presented schemes can improve the estimation performance compared with the convolutional scheme.

• Journal of Power Electronics
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• v.10 no.2
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• pp.171-175
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• 2010

This paper introduces the application of a SUI PID controller for permanent magnet (PM) drive systems. The drive system model is developed via FO control. Simulation of the system is carried out to predict the performance at no load and under load. The results and comparisons indicate that application of a SUI PID controller is effective for sensorless PM drive systems.

• Journal of the Korean Society of Tobacco Science
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• v.6 no.1
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• pp.94-96
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• 1984

The effects of redrying, steaming, toasting, and drying & cooling chamber in the tobacco manufacturing Process on the mortality of three stages of the cigarette beetle, Lasioderma serricorne F., 1.e. eggs, larvae, and adults, were examined. Mortality of the three stages the cigarette beetle in each process was 100%, respectively.