• 한국해양학회지
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• 제5권1호
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• pp.6-13
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• 1970

Ten days and monthly mean temperatures were analysed daily data observed during July, 1916 to March, 1970 statistically. Periodic characters were calculated by Δn, new method of approximate solution of Schuster Method. According to ten days mean temperatures, annual variation function is F($\theta_d$)=16.29-5.27 cos $\theta_d$+0.75 cos2 $\theta_d$-3.14 sin $\theta_d$+1.16 sin2 $\theta_d$-0.63 sin $\3{theta}_d$, where $\theta_d$=$-\frac{\pi}{18}$(d-3), d is the order of ten days period, 1 to 36. Annual mean water temperature is 16.3$^{\circ}C$, minimum in the last ten days of February 10.9$^{\circ}C$, maximum in the last ten days of August 24.5$^{\circ}C$. Periodic character of secular variation shows 11 year and its curve is F($\theta_y$)=16.29+0.53 cos $\theta_y$ -0.16cos $2{\theta}_y$+0.10 cos$3{\theta}_y$-0.10 sin $\theta_y$, where $\theta_y$=2$-\frac{2\pi}{11}$(y-1920), y is calendar year. And the relation between air temperature x and water temprature y is following. y=9.67 1.035$\^x$

• 한국환경과학회지
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• 제30권12호
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• pp.983-991
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• 2021

The role of the distribution basin role is to apportion incoming raw water to the primary sedimentation basin as part of the water treatment process. The purpose of this study was to calculate the amount of water in the distribution basin using computational fluid dynamics (CFD) analysis and to find a way to improve any non-uniformity. We used the Taguchi method and the minitab tool as optimization methods. The results of the CFD calculation showed that the distribution flow had a deviation of 5% at the minimum inflow, 10% at the average inflow, and 22% at the maximum inflow. At maximum flow, the appropriate heights of the 7 weirs(C, D, A, B, E, F, G) were 40 mm, 20 mm, 20 mm, 0, 0, 0, and 20 mm, respectively, according to the Taguchi optimization tool. Here, the maximum deviation of the distribution amount was 9% and the standard deviation was 23.7. The appropriate heights of the 7 weirs, according to the Minitab tool, were 40 mm, 20 mm, 20 mm, 0, 0, 0, and 20 mm, respectively, for weirs C, D, A, B, E, F, and G. Therefore, the maximum deviation of the distribution amount was 8% and the standard deviation was 17.1, which was slightly improved compared to the Taguchi method.

• Journal of Biosystems Engineering
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• 제27권2호
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• pp.89-96
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• 2002

The trend of consumption of vegetable soybeans is increasing because they are recognized as the clean vegetable. The works requiring the most intensive labor are threshing and seperation ones, and they form about 80% of total labour for vegetable soybeans production. It is necessary to develop the vegetable soybeans-thresher for the sake of cost down of vegetable soybeans production. The purpose of this study is to acquire the basic informations to design of the vegetable soybeans-thresher. We make the experimental system which control the speed of threshing cylinder and the teeth gap and investigate the detachment forces. The result are as follows ; The ratio of un-threshed soybeans-pod to stem after threshing work is decreasing as the threshing cylinder speed increases: 0.0% and 2.8% at 55m/s and 18m/s of threshing cylinder speed respectively. Also the ratio of un-threshed soybeans-pod to stem is shown as 2.0% below in the condition of 64~160mm of teeth gap and over 28m/s of threshing cylinder speed. The damaged pod ratio of detached soybeans after threshing work is decreasing as the threshing cylinder speed increases: 4.8% and 1.3% at 55m/s and 18m/s of threshing cylinder speed respectively. The minimum damaged pod ratio of detached soybeans are shown as 1.0%, 1.5% and 1.9% at 18m/s, 28m/s and 37m/s of threshing cylinder speed respectively. The average detachment forces of pods are shown as 1.5kg$_{f}$ for 3 grains, 1.2kg$_{f}$ for 2 grains and 0.8kg$_{f}$ for 1 grain respectively. The maximum detachment force of pod is shown as 2.7kg$_{f}$ for 3 grains. grains.

• 한국학교보건학회지
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• 제18권1호
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• pp.47-58
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• 2005

Purpose:　This study is a descriptive correlation survey with the purpose of identifying the relationship between family function and hope in adolescents. It was done to provide basic data for developing family centered nursing strategies to promote adolescents' hope. Methods: The subjects of this study were 1030 high school students in J city. Data were analyzed with SPSS 10.0 program. Frequencies and percentages were used to compare the subjects' general characteristics. Minimum values, maximum values, mean scores and mean grades were used to identify the level of family function and hope. Pearson's correlation coefficient was used to analyze the relationship between family function and hope in adolescents, and t-test, ANOVA, and Scheffe test were used to examine the level of family function and hope by general characteristics. Results:　1. The level of adolescents' family function ranged from 26 to 97, the mean score was 66.85$\pm$13.16, and the mean grade was 2.76$\pm$0.52. 2. The level of adolescents' hope ranged from 55 to 153, the mean score was 111.48$\pm$17.64 and the mean grade was 2.78$\pm$0.44.　3. It showed that there is a significantly positive correlation (r=0.546, p=.000) between adolescents' family function and hope. That is, the better family function adolescents have, the higher level of hope they have. 4. Adolescents' family function showed significant differences according to school record (F=6.363, p=.002), school life satisfaction (F=4.922, p=.007), father's education (F=2.640, p=.048), mother's education (F=3.586, p=.013) and domestic economy status(F=3.022, p=.049).　5. Adolescents' hope showed significant differences according to religion (t=2.018, p=.044), school type (t=2.567, p=.010), school record (F=9.712, p=.000), school life satisfaction (F=11.367, p=.000), father's education (F=4.632, p=.003), mother's education (F=4.709, p=.003), domestic economy status (F=4.235, p=.015), relationship with friends (F=8.187, p=.000), and subjective health condition (F=5.490, p=.001). Conclusion: First, in order to improve adolescents' family function, which encourages hope in adolescents, it is necessary to develop nursing interventions and to make further studies.　Second, it is necessary to develop instruments for improving Korean adolescents' family function and hope. Third, further studies are required to improve adolescents' family function and hope in special situations such as disease, drug abuse and juvenile delinquent.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제11권1호
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• pp.59-64
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• 2011

In 2001, the notion of a fuzzy poset defined on a set X via a triplet (L, G, I) of functions with domain X ${\times}$ X and range [0, 1] satisfying a special condition L+G+I = 1 is introduced by J. Negger and Hee Sik Kim, where L is the 'less than' function, G is the 'greater than' function, and I is the 'incomparable to' function. Using this approach, we are able to define a special class of fuzzy posets, and define the 'skeleton' of a fuzzy poset in view of major relation. In this sense, we define the linear discrepancy of a fuzzy poset of size n as the minimum value of all maximum of I(x, y)${\mid}$f(x)-f(y)${\mid}$ for f ${\in}$ F and x, y ${\in}$ X with I(x, y) > $\frac{1}{2}$, where F is the set of all injective order-preserving maps from the fuzzy poset to the set of positive integers. We first show that the definition is well-defined. Then, it is shown that the optimality appears at the same injective order-preserving maps in both cases of a fuzzy poset and its skeleton if the linear discrepancy of a skeleton of a fuzzy poset is 1.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.581-582
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• 2006

In this paper, we investigate three different types of multi-fingered layout nMOSFET devices with varying $W_f$(unit finger width) and $N_f$(number of finger). Using layout modification, we improve $f_T$(current gain cutoff frequency) value of 15GHz without scaling down, and moreover, we decrease $NF_{min}$(minimum noise figure) by 0.23dB at 5GHz. The RF noise can be reduced by increasing $f_T$, choosing proper finger width, and reducing the gate resistance. For the same total gate width using multi-fingered layout, the increase of finger width shows high $f_T$ due to the reduced parasitic capacitance. However, this does not result in low $NF_{min}$ since the gate resistance generating high thermal noise becomes larger under wider finger width. We can obtain good RF characteristics for MOSFETs by using a layout optimization technique.

• Membrane and Water Treatment
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• 제10권2호
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• pp.155-163
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• 2019

The roles of polypropylene (PP) beads and pH on membrane fouling and treatment efficiency were investigated in a hybrid advanced water treatment process of tubular carbon fiber membranes (ultrafiltration (UF) or microfiltration (MF)) and PP beads. The synthetic feed including humic acid and kaolin flowed inside the membrane, and the permeated contacted the PP beads fluidized in the space between the membrane and the module with UV irradiation and periodic water back-flushing. In the hybrid process of UF ($0.05{\mu}m$) and PP beads, final resistance of membrane fouling ($R_f$) after 180 min increased as PP beads increased. The turbidity treatment efficiency was the maximum at 30 g/L; however, that of dissolved organic matters (DOM) showed the highest at PP beads 50 g/L. The $R_f$ strengthened as pH of feed increased. It means that the membrane fouling could be inhibited at low alkali condition. The treatment efficiency of turbidity was almost constant independent of pH; however, that of DOM showed the maximum at pH 5. For MF ($0.1{\mu}m$), the final $R_f$ was the minimum at PP beads 40 g/L. The treatment efficiencies of turbidity and DOM were the maximum at PP beads 10 g/L.

• 한국농공학회지
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• 제15권4호
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• pp.3160-3169
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• 1973

Rainfall, evaporation, and permeability of water are the most important factors in determining the demand of water. The Daegu area has only a meteorologi observatory and there is not sufficient data for adapting the advanced method for derivation of the estimated of evaporation in the Daegu area. However, by using available data, the writer devoted his great effort in deriving the most reasonable formula applicable to the Daegu area and it is adaptable for various purposes such as industry and estimation of groundwater etc. The data used in this study was the monthly amount of evaporation of the Daegu area for the past 13 years(1960 to 1970). A year can be divided into two groups by relative degrees of evaporation in this area: the first group (less evaporation) is January, February, March, October, November, and December, and the second (more evaporation) is April, May, June, July, August, and September. The amount of evaporation of the two groups were statistically treated by the theory of probability for derivation of estimated formula of evaporation. The formula derved is believed to fully consider. The characteristic hydrological environment of this area as the following shows: log(x＋3)=0.8963＋0.1125$\xi$..........(4, 5, 6, 7, 8, 9 month) log(x-0.7)=0.2051＋0.3023$\xi$..........(1, 2, 3, 10, 11, 12 month) This study obtained the above formula of probability of the monthly evaporation of this area by using the relation: $F_(x)=\frac{1}{{\surd}{\pi}}\int\limits_{-\infty}^{\xi}e^{-\xi2}d{\xi}\;{\xi}=alog_{\alpha}({\frac{x_0+b'}{x_0+b})\;(-b<x<{\infty})$ $$log(x_0＋b)=0.80961$ $$\frac{1}{a}=\sqrt{\frac{2N}{N-1}}\;Sx=0.1125$$ $$b=\frac{1}{m}\sum\limits_{i-I}^{m}b_s=3.14$$ $$S_x=\sqrt{\frac{1}{N}\sum\limits_{i-I}^{N}\{log(x_i+b)\}^2-\{log(x_i+b)\}^2}=0.0791$$ (4, 5, 6, 7, 8, 9 month) This formula may be advantageously applied to estimation of evaporation in the Daegu area. Notation for general terms has been denoted by following: $W_(x)$: probability of occurance. $$W_(x)=\int_x^{\infty}f(x)dx$$ P : probability $$P=\frac{N!}{t!(N-t)}{F_i^{N-{\pi}}(1-F_i)^l$$ $$F_{\eta}:\; Thomas\;plot\;F_{\eta}=(1-\frac{n}{N+1})$$ $X_l\;X_i$: maximun, minimum value of total number of sample size(other notation for general terms was used as needed)

• Animal Bioscience
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• 제34권8호
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• pp.1375-1381
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• 2021

Objective: This study was conducted to determine the effect of freeze-thawed cycles (Fresh meat, F-T 1 cycle and F-T 2 cycles) on the quality characteristics of porcine longissimus dorsi muscle. Methods: A total of 20 three-crossbred pigs (Duroc×[Large White×Landrace]) were randomly obtained from a commercial slaughterhouse in Thailand. Muscle samples were immediately taken from 10 to 11th of the longissimus dorsi for histochemical analysis. The muscles were cut into 2.54 cm-thick chops. A minimum of 20 chops were used for each treatment (fresh meat, freeze-thawed 1 and 2 cycles). Individually chops were packaged in polyethylene bags and frozen at -20℃ for 6 months followed by thawing in refrigerator at 4℃ for 24 h (the 1st freeze-thawed cycle). The freeze-thawed procedure was repeated for two cycles (the 2nd freeze-thawed cycle). Thawing loss, shear force value, citrate synthase activity and muscle fiber characteristics were determined on the muscles. Results: Results showed that increasing of freeze-thawed cycle increased the thawing loss (p<0.01) and citrate synthase activity (p<0.001). Shear force value of fresh meat was higher than freeze-thawed 1 and 2 cycles (F-T 1 cycle and F-T 2 cycles). Freeze-thawed cycles affected muscle characteristics. Muscle fiber area and muscle fiber diameter decreased with an increasing number of freeze-thawed cycles (p<0.001), while the thickness of endomysium and perimysium were increased (p<0.001). Conclusion: Repeated freeze-thawed cycles degraded muscle fiber structure and deteriorated pork quality.

• 한국항해학회지
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• 제6권2호
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• pp.13-33
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• 1982

The NAVSTAR/GPS is a satellite-based navigation system that will provide extremely accurate three-dimensional position and velocity information to users anywhere on or near the earth. This system has been studied primarly for military use and thus the results of studies are seldom obtainable for civilian use up to date. Expecting this system to be opened to civilian use in the future, this paper aims to the collection of basic data of the PN phase modulated communication system adopted in the GPS system by computer simulation. The results of studies are as follows; 1) The PN phase modulation of the speed of 106b/s can be simulated by Fourier summation, the spectrum region which can be restricted is in the region of 0.5-1.5 MHz and spectrum number required is over than 270. 2) By computer simulation, it is verified that optimum r.f filter bandwidth is about 0.3 MHz for the case of $10^6$b/s PN codes phase modulated in 1.575GHz carrier. 3) In case that PN rate to data rate is between 10 and 100, the allowable minimum SNR to demodulate data signal correctly by optimum LPF is about 0.3. It is also verified that the larger the frequency ratio of PN code to the data code, the lower the allowable minimum SNR required.