• Journal of the Korean Institute of Intelligent Systems
• /
• v.13 no.3
• /
• pp.360-365
• /
• 2003

In this paper, GMDH(Croup Method of Data Handling) algorithm which is proved to be more excellent in efficiency and accuracy of practical use of data is applied to electric power demand forecasting. As a result, it became much easier to make a choice of input data and make an exact prediction based on a lot of data. Also, we considered both economy factors(GDP, export, import, number of employee, number of economically active population and consumption of oil) and climate factors(average temperature) when forecasting. We assumed target forecast period from first quarter 1999 to first quarter 2001, and suggested more accurate forecasting method of electric power demand by using 3-step computer simulation processes(first process for selecting optimum input period, second for analyzing time relation of input data and forecast value, and third for optimizing input data) for improvement of forecast precision. The proposed method can get 0.96 percent of mean error rate at target forecast period.

• Korean Journal of Agricultural Science
• /
• v.43 no.3
• /
• pp.450-458
• /
• 2016

High performance small and mid-sized tractors are required for dryland and orchard operations. A power transmission system is the most important issue for the design of high performance tractors. Many operations, such as loading and lifting, use hydraulic power. In the present study, a hydraulic power transmission system for the 3-point hitch of a 50 kW narrow tractor was developed and its performance was evaluated. First, major components were designed based on target design parameters. Target operations were spraying, weeding, and transportation. Main design parameters were determined through mathematical calculation and computer simulation. The capacity of the hydraulic cylinder was calculated taking the lifting force required for the weight of the implements into consideration. Then, a prototype was fabricated. Major components were the lifting valve, hydraulic cylinder, and 3-point hitch. Finally, performance was evaluated through laboratory tests. Tests were conducted using load weights, lift arm sensor, and lift arm height from the ground. Test results showed that the lifting force was in the range of 23.5 - 29.4 kN. This force was greater than lifting forces of competing foreign tractors by 3.9 - 4.9 kN. These results satisfied the design target value of 20.6 kN, determined by survey of advanced foreign products. The prototype will be commercialized after revision based on various field tests. Improvement of reliability should be also achieved.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.18 no.3
• /
• pp.219-226
• /
• 2005

In this study, the problem formulation and solution technique using genetic algorithms for design optimization of laminate composite cylindrical beam section are presented. The hollow cylindrical beams we usually used in the wheel chair. If the weight of wheel chair is reduced, it will lead to huge improvement in passenger's mobility and comfort. In this context, the replacement of steel by high performance and light weight composite material along with optimal design will be a good contribution in the process of weight reduction of a wheel chair. An artificial genetics approach for the design optimization of hollow cylindrical composite beam is presented. On applying the genetic algorithm, the optimal dimensions of hollow cylindrical composite beams which have equivalent rigidities to those of corresponding hollow cylindrical steel beams are obtained. Also structural analysis is conducted on the entire wheel chair structure incorporating Tsai-Wu failure criteria. The maximum Tsai-Wu failure criteria index is $0.192\times10^{-3}$ which is moth less than value of 1.00 indicating no failure is observed under excessive loading condition. It is found that the substitution of steel by composite material could reduce the weight of wheel chair up to 45%.

• Journal of Digital Convergence
• /
• v.8 no.2
• /
• pp.55-68
• /
• 2010

This study identifies perceived importance and relative education necessity of entrepreneurship education program of university students. This research examine the major 5 factors of invention education program and identified the improvement of relative invention education program relation to entrepreneurship process. The sample survey of this research are 125 university student respondents and 5 invention entrepreneurs are participated. Research methods used means, percentile, frequency and factor analysis. Major findings are as follows; the selected course category of factor analysis categorized the understanding of invention concept, invention and management, invention and creativity, invention and patent and invention exercise. The mean value of perceived importance that invention and management, invention exercise, invention and creativity, invention concept and invention and patent are in order. But the perception of invention entrepreneurs to patent, management, creativity, invention exercise and invention concepts are in order. And the sub invention program's necessity degree relation to 'management and exercise' are higher than others. This study suggested that invention education program reinforcing the invention management and student takes interesting patent contents which accepted exercise program with easy.

• Journal of the Ergonomics Society of Korea
• /
• v.30 no.3
• /
• pp.427-435
• /
• 2011

Objective: The objective of this study was to evaluate a work of building cleaners using the ergonomic methods. Background: Previous studies about cleaning worker describe typical physical demands of this work. They found that the most significant risk factors associated with the physical work of cleaners are static loads and repetitive movements and high output of force. Method: A head of ergonomics estimation was work analysis(define of combined task, work tool, work time and frequency of combined task) and posture analysis of worker. Results: The results showed that combined task of building cleaners was classification sweeping, mopping(wet), mopping(oil), moving barrels/carts, dumping trash bags, scrubbing, arrangement of cleaning tool, arrangement of circumferential, moving of cleaning tool, and waiting. The work time of combined task such as mopping(wet) and scrubbing indicated high ratio. The posture analysis of building cleaners indicated high value in bending of the head, lower arm, and hands. Conclusion: The findings appear to indicate that building cleaner were related to high risk of work-related musculoskeletal disorders. So, building cleaner would be required an interventional strategy, improvement of cleaning tools and working environment. Application: If ergonomics rule can be integrated into existing cleaning tools and work environments, the risk of occupational injuries will be reduced.

• The Journal of Fisheries Business Administration
• /
• v.34 no.1
• /
• pp.137-156
• /
• 2003

Increasingly, leisure time is being used for outdoor recreational activities, and fishing is one of the principal forms of marine recreation. Marine recreational fishing is a popular activity in Korea and this activity has led to the development of a sector of substantial social and economic value. Also it is considered as one of the important outdoor leisure industries in Korea. With rising of income level and development of marine outdoor leisure industries, social, economic demand increase of marine recreational fishing are showing us new advance ability of marine aquatic bio-industry. However the recreational use of fish stocks has become an important consideration in the public and environmental economic analysis of management aspect of fishing, having grown considerably over recent years to reach a level in Korea where the fish stocks and coastal ecosystem has become a significant management problem. we are inevitably facing marine environmental deterioration and overfishing in marine recreational fishing. In this study, not only resources and environmental problems which are occurred by recreational fishers, but also illegal fishing behaviors and other problems such as market's failure are going to analyze basic management theories and methods of recreational fishing through mathematical principals and economic rents which maximize net social benefits. In view of the likelihood of marine recreational fishers adopting high rates of discount, the conservation of fish resources would appear to require continual public surveillance and control of the physical yield and condition of the fish stocks and the optimal use level. The institutional management of recreational fisheries is the way of escaping the collapse of recreational fisheries just like as the situation of management's failure of commercial fisheries worldwide. One of the effective management measure is a license system. In this system, optimal fee is paid by recreational fishers, which prevent them from overfishing, environmental problems to some extents and carry out the optimal number of outings. And money obtained by license fee should be spent for more improvement fishing culture and welfare for marine recreational fishing. Marine recreational fishing is to be promoted under sound conservation and management principles.

• Fashion & Textile Research Journal
• /
• v.15 no.3
• /
• pp.347-357
• /
• 2013

The nursery active-wear uniform designs of Internet shopping malls are simple and similar; however, the latest children's wear trends (mostly composed of training jumpers and pants) do not reflect these qualities. Children's folklore plays (widely used in child education) have an instructive value for the emotional and intellectual development of a child. Nursery active-wear uniform designs applied to children's folklore's plays could be positive for the emotional development and specialized cultural education of children. We designed three nursery active-wear uniforms with three different design concepts (casual, semi-formal and sporty) regardless of sex. The main color of the three nursery active-wear uniforms was yellow. We used three different chroma and values of yellow through three design concepts: Design I of a nursery active-wear uniform (a training suit style with a good activity), Design II of a nursery active-wear uniform (a semi suit style), and Design III of a nursery active-wear uniform (a sportswear style that reflected a sport wear trend). We expressed children's folklore plays in the pattern of a nursery active-wear uniform. The pattern was characterized as a pair of bears flying kites. This pattern was utilized in three nursery active-wear uniforms with the logo and name of the nursery. We modified the designs of active-wear nursery uniforms based on an evaluation of 33 special panels. We made three nursery active-wear uniforms for five-year olds.

• The Journal of Churna Manual Medicine for Spine and Nerves
• /
• v.8 no.2
• /
• pp.151-157
• /
• 2013

Objects : This study is a report on treatment effect of the case that treated by using of Shinbaro pharmacopunture and acupuncture to plantar fasciitis patients. Methods : The four patients diagnosed with Plantar fasciitis were treated by using of Shinbaro pharmacopunture and acupuncture, Algometer Pressure and Numeric rating scale(NRS) were used as the evaluation tool of treatment effect. Results : Shinbaro pharmacopunture and acupuncture showed improvement of symptoms for all patient groups and brought about significant change on numerical value of Algometer Pressure and Numeric rating scale(NRS). Conclusions : The result shows that Shinbaro pharmacopunture and acupuncture can be effective treatment to Plantar fasciitis. Merely later, further study is needed.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.4 no.1
• /
• pp.27-35
• /
• 2002

For the excavation of the rock, blast method is put into operation in most of the construction site in Korea. In comparison to other methods of excavation, blast method has many merits such as improvement in efficiency in operation, reducement of operation period, and etc. However, blast operation also creates much loss due to the blast vibration, noise, and fly rocks. Thus, in this study, we have examined main features, rock fragmentation effect and the application of plasma method the one of shallow vibration method. In this study, the attenuation exponent of blast method operated in the site was 1.39~1.40 and that of the plasma method was analysed to be 1.45~2.23. From the location where the distance between excavation location and observation location was over 15 m, most of excavation vibration were measured to be less than 0.2 kine(cm/sec), which is also the allowed standard value of sensitive buildings, such as cultural assets and computer facilities. According to the result of FFT(Fast Fourier Transform) analysis, the frequency measured through blast method in this site was 30~50 Hz and the frequency of plasma method ranges in between 30~130 Hz.

• Journal of Mushroom
• /
• v.3 no.4
• /
• pp.159-171
• /
• 2005

The supply and demand of mushrooms has increased dramatically as the standard of living has increased and the nutritional and medical value of the mushrooms has been discovered. However, in meeting the demand, the profitability of the mushroom is being reduced. Even though there are many different types of and uses for mushrooms, the overall output production for the last ten years has consistently increased 5.9% per year, and for the last five years('00~'04) 5.2 % per year, and for the last 3 years('02~'04) 2.9% per year- the rate of increase has slowed. Looking at the standard gross income from mushroom production, it has increased 5.2% over the last nine years('95~'03), 1.6% over the last 4 years('00~'03), and 3.2% over the last 3 years('02~'04)-the annual gross income is decreasing. Even though the farmers are producing more mushrooms, the annual gross income is not increasing enough to keep up with the production, and therefore the profitability of mushrooms is decreasing. Since 2002, the constant increase of the output of edible mushrooms such as the Common Mushroom, Oyster Mushroom, King Oyster Mushroom and Winter Mushroom has resulted in a price declines. Before 2004, Korea mainly exported mushrooms, but after 2004 Korea mainly imported mushrooms. The mushroom industry of Korea is nearing the end of the stage of 'supplying domestic demand.' The stages are as follows: demand raised ${\rightarrow}$ supply domestic demand ${\rightarrow}$ export ${\rightarrow}$ country with developed mushroom industry. Therefore, we should have an efficient system to promote the exportation of mushrooms. Not only the exportation of mushroom itself but also the exportation of mushroom spawn, cultivation techniques and processing facilities should be our goal when we formulate the policy.