• Korean Journal of Agricultural Science
• /
• v.14 no.1
• /
• pp.1-15
• /
• 1987

This experiment was conducted to investigate the effect of nitrogen top-dressing and Jangyeopkong was planted under two different seeding time (single cropping-May 15, after barley cropping-June 18), four levels of nitrogen top-dressing (0, 3, 6, 9 kg/10a) and two times of nitrogen top-dressing (Hilling time, Flowering Time). The results obtained are summarized as follow: 1. The days to flowering and maturity were delayed a day longer in hilling times than flowering times of nitrogen top-dressing. 2. The number of nodes of main stem and length of internodes didn't show significance among treatments. But, the number of nodes of branches was much higher when the soybean was planted on May 15, and were higher hilling time than flowering time as the amount of nitrogen top-dressing increased. Especially, the number of nodes of branches was high when 6kg of nitrogen was applied during hilling time. 3. The fresh and dry weight of stem and leaves at 10, 25 and 40 days after flowering were increased by increasing the amount of nitrogen top-dressing. More apparent effect of nitrogen was attained high significant when nitrogen was applied at the time of hilling rather than flowering time. 4. The number and fresh weight of nodule, and dry weight were apparently decreased after barley and were decreased according to the increasing the amount of nitrogen top dressing. The degrees of decreasing was more apparent in the hilling time than in the flowering time. 5. The number of pods per plant, and number and weight of grain per plant were higher when the soybean was planted on May 15, the amount of top dressing increased and hilling time rather than flowering time. Especially, yield component were highest when 6kg of nitrogen was applied during hilling time. Also, the grain yield per 10a showed high significance among treatment, and were high when 6kg of nitrogen was applied during hilling time.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.6 no.2
• /
• pp.155-165
• /
• 1994

In this study, the following factors are investigated from experiments for a vertical parallel plate heat exchanger under the frosting condition ; the growth of frost layer, the characteristics of heat and mass transfer, the change of mass flow rate of the air passing through the heat exchanger, and the pressure drop of the air in the heat exchanger. The amount of heat and mass flux of water vapor transferred from the air stream to the heat exchanger surface is large at the early stage of frosting and then decreases dramatically, and the extent of decreasing rate becomes moderate with time. The frost layer formed near the inlet of the heat exchanger is thicker and denser than that formed near the outlet. It is found that the gradient of the amount of frost along the flow direction increases with time. In the early period of frost formation, the thermal resistance between the air and the cooling plate increases dramatically and then the extent of change decreases with time. Initially the convective thermal resistance is dominant. Then, while the convective thermal resistance decreases with time, the conductive thermal resistance continues to increase with time and finally the conductive thermal resistance becomes dominant.

• Journal of the Korean Society of Costume
• /
• v.41
• /
• pp.185-206
• /
• 1998

The purpose of this study was to improve productivity for maximum effects with the present equipments and staff. This study compared and analyzed the mea-sured time by using stop watch method and MTM, which was the new measuring method. The flow and results of this study were as follows: 1. This study investigated the theoretical background the efficiency for production management, and the way of productivity improvement through documentary research. 2. Setting up the standard flow on the experi-mental company production, making out a process chart and measuring the actual working hour. 3. The study measured the allowance time applying work sampling. 4. Each process of the movement analysis was filmed by video to use basic data. 5. MTM analysis was taken by choosing 10 processes from front bodice according to the basic movement of MTM. Through the results, this study exclude unneccesary movements and suggest a method for working ways. 6. Using the actual working hour measured by a stop watch calculated the pitch time and presumed the amount of daily productivity. 7. The result of the work sampling came out as 38% of allowance rate. It was 13% higher than the standard amount of woman's jacket allowance rate, which was 25%. The most influencing factor was work discussion. That was because there were commuication problem of the work way between the operator and leader. More adequate use of flow table and level passing table was needed. There were the problems that inappropriate places and sizes made the distance of movements longer and often needed more adjustment of works and surroundings. To prevent breakdowns equipments check ups were necessary before works. 8. The results of MTM analysis were as follow : the time was reduced 40% than the actual measured time by a stop watch. This was because the leveling of the operator was included in the real calculation. Also, leveling was included in MTM analysis and all the conditions were standarized. Therefore MTM method was a scientidic measuring way of establishing the standard time. The presented method of this study, suggested an ideal method eliminating unneccesary motions, and presented standardization of works. Improvement of working methods, work condition and simplifying motions in each 10 processes reduced the working time from total 656 seconds to 301 seconds. 9. The way and time of working was linked together in the MTM analysis methods. Thus data from MTM help suggest not only establishing standard time but also establishing stan-dard work. Plus it includes various ability for improvements of working ways. So it is an objective method which can be widely used in other work studies. 10. The function of a time study is to determine the amount of work produced with a given method. The work rate is used to establish the cost of labor. The wage of worker must be calculated per unit time which is deter-mined before the time study is made. This study tried to introduce the incentive rule for deciding wages according to the standard time by MTM method.

• Current Research on Agriculture and Life Sciences
• /
• v.32 no.3
• /
• pp.125-130
• /
• 2014

This study used transmission electron microscopy (TEM) to investigate the micro-morphological features of two formaldehyde to urea (F/U) mole ratio liquid urea-formaldehyde (UF) resins with three hardener levels as a function of the curing time. The micro-morphological features of the liquid UF resins were characterized after different curing times. As a result, the TEM examination revealed the presence of globular/nodular structures in both liquid UF resins, while spherical particles were only visible in the low F/U mole ratio resins. The high F/U mole ratio liquid UF resins also showed extensive particle coalescence after adding the hardener, along with the appearance of complex filamentous networks. When the resins were cured with a higher amount of hardener and longer curing time, the spherical particles disappeared. For the low mole UF resins, the particles tended to coalesce with a higher amount of hardener and longer curing time, although discrete spherical particles were still observed in some regions. This is the first report on the distinct features of the crystal structures in low F/U mole ratio UF resins cured with 5% hardener and after 0.5 h of curing time. In conclusion, the present results indicate that the crystal structures of low F/U mole ratio UF resins are formed during the curing process.

• Journal of the Korean Society of Food Culture
• /
• v.15 no.1
• /
• pp.1-8
• /
• 2000

This study was to investigate the effects of concentration of malt extract in Sikhye manufacture on saccharification time, shapes of saccharified rice(the cooked rice) and sensory evaluation score of Sikhye. The optimum concentration of malt extract to reduce saccharification time and to keep desirable shapes of saccharified rice was 4 times (rice 24g, malt 28g and D.W. 240ml) as suitable as base composition formula(rice 6g, malt 7g and D.W. 240ml). The shapes of saccharified rice were influenced by the concentration of malt extract, the saccharification time and the shapes of steamed rice before saccharification. A good taste(softness) of Sikhye rice and the desirable shapes of saccharified rice were more suitable in the case of a small amount of unsaccharified starch than in the case of finishing saccharification. The optimum saccharification time to keep the desirable shapes of saccharified rice was 240min and also was desirable between 210 and 270min. To keep a good taste(softness) and the desirable shapes of saccharified rice, and to reduce the manufacturing time, it is desirable to in mass production of Sikhye add 3 times more water after making Sikhye in the ratio of rice 24g, malt 28g and water 240ml. In this case the whole amount will become 4 times as much as the original one.

• Journal of the military operations research society of Korea
• /
• v.24 no.1
• /
• pp.41-57
• /
• 1998

Since the aircraft has a property of moving in the three-dimensional space, it may cause personally and financially critical damage in the case of an accident. Among the causes of aircraft accident, human factor has occupied about 70% of all accidents. Specially, fatigue among human's problems has been studied earlier than any other factor. Fatigue has been the cause of 75% of accidents that are related to human factor. So many studies have been conducted. But the direction of these studies mainly attach importance to the sleep loss and circadian rhythm. Limitation for flight time of ICAO is 8 hours per day, civil airlines in domestic line also adopt the limitation. But this rule is not based on human's performance but compromise between labor and management. The long-haul flight brings about a mental block to pilot. This mental block decreases performance of pilot and loses a lot of important information. So this may cause many accidents. This paper is to offer optimal flight time according to the amount of fatigue due to increasing flight time. The optimal flight time is searched through the field experiment. The experiment has adopted two methods. One is to examine pilot's objective fatigue accumulation rate through the critical fusion frequency, and another is to investigate pilot's subjective fatigue feeling through the fatigue subjective symptoms investigation table.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.8
• /
• pp.1497-1504
• /
• 2009

This Paper Propose a method to reduce the calculation time in JPEG2000. That is, if a coefficient is estimate a upper-level subband and its descendents skip the scan process. There is a trade-off relationship between the calculation time and the image quality or the amount of output data, the calculation time and the amount of output data decreases, but the image degradation increases. The experimental results showed that in calculation time was 35% in average, which means that ls ge ses. The ein calculation time and output data can be obtls ed with a cost of an acceptlble image quality degradation.

• Journal of applied mathematics & informatics
• /
• v.28 no.1_2
• /
• pp.531-537
• /
• 2010

In this paper, some vacation policies are considered, which can be related to the past behavior of the system. The server, after serving all customers, stays idle or to wait for some time before a vacation is taken. General formulas for the waiting time and the amount of work in the system are derived for a vacation policy. Using the analysis on the vacation system, we derived the waiting time in the sequential bottleneck station.

• Journal of applied mathematics & informatics
• /
• v.8 no.3
• /
• pp.959-973
• /
• 2001

We shall discuss one of some techniques needed to analyze algorithms. It is called a big-O function technique. The measures of efficiency of an algorithm have two cases. One is the time used by a computer to solve the problem using this algorithm when the input values are of a specified size. The other one is the amount of computer memory required to implement the algorithm when the input values are of a specified size. Mainly, we will restrict our attention to time complexity. To figure out the Time Complexity in nonlinear problems of Numerical Analysis seems to be almost impossible.

• Journal of Digital Contents Society
• /
• v.10 no.1
• /
• pp.55-60
• /
• 2009

Due to the development of the Internet, there are a lot of information around, and the amount of this information is growing exponentially. The information management systems, which are built to manage the numerous amount of information, helps the user retrieve information more accurately and efficiently. However, mobile systems and its built-in file systems, lack in information management and has a limited processing power for real-time data. This paper suggests the middleware system for effective management of large data and enabling real-time data processing. To show the possibility of middleware, the paper implemented a real-time alarm scheduler, which links web database systems and mobile phones.