• Journal of the Korean Magnetics Society
• /
• v.2 no.1
• /
• pp.1-7
• /
• 1992

Deuterium was injected into melt-spun ribbons of ${\alpha}-Fe_{90}Zr_{10}$ using the electrolytic hydrogenation method, and the magnetic properties of these ${\alpha}-D_{x}Fe_{90}Zr_{10}$ ribbons were studied. By comparing these results with those of ${\alpha}-H_{x}Fe_{91}Zr_{9}$, the effects of phonons to magnetic properties were investigated. The Curie temperature $T_{c}$, and the spontaneous magnetizations of the $D_{47}Fe_{90}Zr_{10}$ and the $Fe_{90}Zr_{10}$ were studied using the Mbssbauer spectroscopy. From these investigations, it was found that the Curie temperature of $D_{x}Fe_{90}Zr_{10}$ was 75K higher than that of $Fe_{90}Zr_{10}$. It was believed that this indicated the importance of local deformation to the amorphous magnetism. Also by comparing the spontaneous magnetizations of $D_{47}Fe_{90}Zr_{10}$ with those of $Fe_{90}Zr_{10}$ as a function of temperature, it was found that the deuterium injection reduced the fluctuation of exchange integral.

• Korean Journal of Construction Engineering and Management
• /
• v.7 no.5
• /
• pp.159-166
• /
• 2006

It was found that Korean Standard of Estimate which has been used as the only basis of cost estimate of public construction projects had some side effects such as jerry-build construction and over-estimation because it failed to reflect the current price and the state-of-the-art construction methods in a changing construction environment. Therefore, the government decided to gradually introduce historical construction cost into cost estimate of public construction projects from 2004. This paper presents analytic criteria and a process model for deducing more current and reasonable historical construction cost for contract items from not only previous contract prices but also all of the other bid prices that were not contracted. The procedure of estimating actual unit cost proposed in this paper focuses on the removal of abnormal values including strategically too low or high prices and the time correction. In addition, basic research is conducted for the correction of actual unit cost through the analysis of fluctuation of bid price depending on bidding types and rates of successful bid. It is anticipated that the effective use of the proposed process model for estimating actual unit cost would make the cost estimation more current and reasonable.

• The Journal of the Acoustical Society of Korea
• /
• v.37 no.3
• /
• pp.147-155
• /
• 2018

In this paper, we tried to find out sound quality metrics to express discomfort of overload excavator noise and to develop sound quality indexes through multiple regression analysis by using them. For this purpose, the interior noise of cabin under overload condition was recorded for six excavator models with different noise properties and Jury test was carried out by PCM (Paired Comparison Method) and MEM (Magnitude Estimation Method). Jury test result with low consistency was classified into two groups with different preference tendencies by cluster analysis and multiple regression analysis was conducted in order to find out which sound quality metrics have significant effects on discomfort(low preference). As a result, we figured out that the sound quality metrics to express the discomfort were the partial loudness (= $PN_{10Bark}$) between 0 and 10 Bark in case of group1 and the difference between engine noise(= $dB_{EG}$) and hydraulic system noise ($dB_1$) in case of group2. Using the results of preference ranking and tendency analysis of PCM followed by the correlation analysis between PCM and MEM, the more reliable results were adopted by excluding the data with low consistency obtained from Jury test via MEM.

• Proceedings of the Botanical Society of Korea Conference
• /
• 1987.07a
• /
• pp.133-148
• /
• 1987

Gibberellin(GA) 3-$\beta$ hydroxylation is very important for the shoot elogation in the higher plants, since only 3$\beta$-hydryoxylated GAs promote shoot elogation in several plants. Fluctuation of 3$\beta$-hydryoxylase activity was examined during seed maturation using two cultivars of , P. vulgaris, Kentucky Wonder (normal) and Masterpiece (dwarf). Very immature seeds of both cultivars contain high level of 3$\beta$-hydroxylase activity (per mg protein). Both cultivars showed maximum of enzyme activity (per seed) in the middle of their maturation process. Gibberellin 3$\beta$-hydroxylase catalyzing the hydroxylation of GA20 to GA1 was purified 313-fold from very early immature seeds of P. vulgaris. Crude soluble enzyme extracts were purified by 15% methanol precipitation, hydrophobic interaction chromatogrphy, DEAE ion exchange column chromatography and gel filtration HPLC. The 3$\beta$-hydroxylase activity was unstable and lost much of its activity duting the purification. The molecular weight of purified enzyme was extimated to be 42, 000 by gel filtration HPLC and SDS-PAGE. The enzyme exhibited maximum activity at pH 7.7. The Km values for [2.3-3H] GA20 and [2.3-3H]GA9 were 0.29 $\mu$M and 0.33 $\mu$M, respectively. The enzyme requires 2-oxoglutarate as a cosubstrate; the Km value for 2-oxoglutarate was 250 $\mu$M using 3H GA20 as a substrate. Fe2+ and ascorbate significantly activated the enzyme at all purification steps, while catalase and BSA activated the purified enzyme only. The enzyme was inhibited by divalent cations Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+ and Hg2+. Effects of several GAs and GA anaogues on the putrified 3$\beta$-hydroxylase were examined using [3H]GA9 and GA20 as a substrates. Among them, GA5, GA9, GA15, GA20 and GA44 inhibited the enzyme activity. [13C, 3H] GA20 was converted by the partially purified enzyme preparation to [13C, 3H]GA1, GA5 and GA6, which were identified by GC-MS, GA9 was converted only GA4, GA15 and GA44 were converted to GA37 and GA38, respectively. GA5 was epoxidized to GA6 by the preparation. This suggests that 3$\beta$-hydroxylation of GA20 and epoxidation of GA5 are catalyzed by the same enzyme in P, vulgaris.

• Korean Journal of Plant Resources
• /
• v.18 no.2
• /
• pp.270-278
• /
• 2005

This experiment was conducted to develop and design a product that is convenient and helpful to both patients and ordinary people who want to maintain their health. In this experimentation, the experimental rat have been given with high fat food to induce Diabetes. Organic brown rice was given as their main energy source and natural complex food, most of materials were freeze-dried, was given to observe its effects on their glucose amount in the plasma. The results are as follows. During 28 days of basal diets, as observing their weight variations, normal group gained weights, but the natural complex food(NCF) groups lost their weights. As comparing the amount of neutral fat levels in the plasma between the diabetes group who just had basal group and one who had NCF, group with NCF groups' level was much lower than the other group who just had basal food. As comparing total cholesterol levels in the plasma, with diabetes group with basal food, $50\%$ and $100\%$ NCF groups' levels were lowered than that group. Regarding HDL-cholesterol level, all NCE groups had around 30mg/dl and there were not much fluctuation among groups. As for LDL-cholesterol level, the $100\%$ NCF group had the lowest level and showed almost the same as the normal group. The amounts of the glucose in the plasma were lowered in all NCF groups. Among those NCE groups, $100\%$ NCF group had 120mg/dl to reach almost the same as the normal group.

• Journal of the Korean Vacuum Society
• /
• v.18 no.1
• /
• pp.37-43
• /
• 2009

Temperature and injection current dependence of electroluminescence(EL) spectral intensity of the $In_xGa_{1-x}N$/GaN multi-quantum wells(MQW) have been studied over a wide temperature range and as a function of injection current level. It is found that a temperature-dependent variation pattern of the EL efficiency under very low and high injection currents shows a drastic difference. This unique EL efficiency variation pattern with temperature and current can be explained field effects due to the driving forward bias in presence of internal(piezo and spontaneous polarization) fields. Increase of the indium content in $In_xGa_{1-x}N$/GaN multiple quantum wells gives rise to a redshift of 80 meV and 22 meV for green and blue MQW, respectively. It can be explained by carrier localization by potential fluctuation of multiple quantum well and MQW structures also shows a keen difference owing to the different indium content in InGaN/GaN MQW.

• Journal of the Korea Concrete Institute
• /
• v.17 no.2 s.86
• /
• pp.273-297
• /
• 2005

In construction site, there are some occasions where concrete under initial curing is being affected by nitration from nearby vibration sources. To study these effects, in this paper, strength characteristics of concrete specimens subjected to continuous vibration up to 12 hours in vertical direction after concrete placement were observed. And through the vibration time control experiment where a number of time combinations consisted of times before and after applying vibration during initial curing period were used as experimental parameters, possibility of concrete strength improvement was investigated. From the experimental results, it could be seen that the concrete strengths were mostly decreased due to the increase of vibration velocity during initial curing period. But fluctuation ratio of concrete strength did not have any close correlations with the vibration times. And results of vibration time control experiment showed that if times before applying vibration sustains at least more than 3 hours, subsequent vibrations after that hours do not affect the concrete strength in any unfavorable ways.

• Journal of Bio-Environment Control
• /
• v.21 no.4
• /
• pp.348-353
• /
• 2012

This study was conducted to figure out the possibility of non-drainage in muskmelon (Cucumis melo L.) hydroponics culture. Plants were grown under 3 different levels of drainage, standard (20~40%, SD), minimum (5~10%, MD), and non-drainage (ND). Throughout cultivation periods, constant water content and electrolyte conductivity changes in root zone were observed in SD in the range of 60~70% and $1.5{\sim}2.5dS{\cdot}m^{-1}$, respectively. ND treatment caused the fluctuation in water content and electrolyte conductivity of root zone and its change ranges were 30~50% in water content and $2{\sim}6dS{\cdot}m^{-1}$ in electrolyte conductivity, but ND treatment did not decrease fruit quality. Even if fruit fresh weight was slightly lower in ND with 1,863 g, than in SD with 1,990 g, the fruit weight in ND meets standard market size, 1,800~2,000 g. Higher soluble solids content was observed in fruit in ND than in SD and MD. Total amount of drainage per plant was 27,718, 15,769 and 2,346 mL in SD, MD and ND, respectively. SD showed $83.2m^3$ drainage, 34.5% drainage of irrigation amount whereas required total irrigation amount in ND was very low with $7m^3$.

• Horticultural Science & Technology
• /
• v.18 no.1
• /
• pp.9-13
• /
• 2000

Cultivation of onions in Korean peninsula is so restricted to Southern region, mainly due to inadequate air temperature for the growth of onions in this region. This sometimes resulted in unstable supply of onions. The fluctuation of market prices mainly results from the limited production of onions in such restricted areas. Onions are usually transplanted at the end of fall and cultivated until the beginning of next summer. This study was designed to examine the possibility of extending production region of onions by adopting the plug seedling system, and the effects of plug seedling age, transplanting date, plug cell volume, and variety on the yield of onions were investigated. Transplanting date (Mar. 15 or Apr. 15) did not affect the yield of onions. However, 60-day-old seedlings produced significantly greater bulb yield (107.2 ton/ha) than those of 30- or 90- day-old seedlings. Bulb yields of seedlings raised in 128 and 72 cell trays were 125.0 and 120.8 ton/ha, which were significantly greater than those in other cell trays. Yield of seedlings raised in 406 cell trays was the lowest. Seedlings of mid-late 'Chenjuwhang' yielded 130.5 Ton/ha, which was significantly higher than those of other varieties. Considering the rainy season during early summer, we suggest that seedlings of onions raised for 60 days and transplanted on Mar. 15 should be advantageous in producing of marketable bulbs and that an early 'Yongbongwhang' should be the best variety.

• Korean Journal of Community Nutrition
• /
• v.9 no.2
• /
• pp.161-172
• /
• 2004

The dietary habits of middle-aged obese, overweight and normal subjects were evaluated for the purpose of providing the background information of the degenerative disease control. A survey was conducted with 293 subjects (121 males and 172 females) between the ages 40-64 and they were divided into three groups of normal (BMI 18.5-22.9), overweight (BMI 23-24.9) and obese ($BMI\geq25$) based on the criteria of Korean Obesity Association (2000). The mean age of the subjects was $52.0\pm7.3(male)\;and\;51.9\pm6.9$ (female). Socioeconomic levels of subjects belong to the mid-upper class, since 71.9% of the males and 39.5% of the females received above a college education. More than 40% (44.6%) of males and 22.1% of females were obese, and educational background did not affect the obesity rate in males, whereas in females those who received lower education had a higher rate of obesity (p ＜ 0.001). The subjects had a similar degree of drinking to the national average value. but had a lower degree of smoking. The obese group had the higher rate of drinking (p ＜ 0.01) and smoking (p ＜ 0.01). The annual increase in weight, more than 4 kg, was 8.8% for normal group and 30.9% for obese group. However, there were no differences in the mean annual increase in weight among the three groups. In females there were greater tendencies of weight changes in obese group (p ＜ 0.05). About 44.9% of subjects responded that they were exercising regularly, and the obese group appeared to put into practice less than the other groups and to use more strenuous exercise. There was the greater rate of skipping dinner in the obese female group (p ＜ 0.05). The unbalanced dietary pattern was found more with normal group than the other groups (p ＜ 0.01). The food consumption frequency by food groups was not different among the groups. The obese group consumed less frequently meats, vegetables and fruits and had higher frequency in fish, legumes and their products, instant or fast food. In all subjects the higher rate of obesity was found with males than females and with those of heavier smoking and drinking, and in females the higher rate of obesity was found with lower education levels, skipping meals and having an unbalanced diet. In middle-aged subjects of this study with higher educational and socioeconomic background factors contributing to the effects of obesity may include smoking, drinking, educational background, skipping meals or unbalanced dietary pattern. The predictable characteristics for the development of obesity can be defined as sudden fluctuation of weights, exercise regularity and intakes of vegetables and fruits.