• Journal of The Korean Society of Grassland and Forage Science
• /
• v.22 no.1
• /
• pp.15-22
• /
• 2002

This study was conducted from April 13 to October 8, 2001 in Jeju to determine the influence of cutting height (2, 4, 6, 8 and 10 cm from the soil surface) on growth, forage yield and chemical composition of kenaf (Hibiscus cannabinus L.). As cutting height was increased from 2 to 10 cm, plant height averaged across two cuttings increased from 157.7 to 184.7 cm. This pattern held fir the number of leaves and branches per plant, stem diameter and plant weight per plant. As cutting height increased from 2 to 10 cm, fresh forage, dry matter, crude protein and TDN yields increased from 85.5 to 113.7MT/ha, from 11.97 to 15.63 MT/ha, from 1.63 to 2.72, and from 4.95 to 7.54 MT/ha, respectively. As cutting height was increased from 2 cm to 10 cm, crude protein, ether extract, nitrogen free extract, and TDN contents increased from 14.2 to 17.6%, 2.9 to 3.9%, 24.2 to 25.8% and 43.1 to 48.5%, respectively, while crude fiber and crude ash contents decreased from 35.5 to 30.4 % and 9.9 to 8.1 %, respectively.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.16 no.5
• /
• pp.137-147
• /
• 2012

In the steel-free bridge concrete deck, steel straps are generally used instead of conventional steel rebar while laterally restrained in the perpendicular direction to the traffic in order fir the arching effect of concrete deck. In this paper, the minimum amount of FRP bar is to be suggested based on the structural strength, crack propagation, stress level and others in order to control cracks. As a result of laboratory tests, the structural strength of deck with 0.15 percentage of steel strap showed improved structural strength including ductility. The long-term serviceability of steel strap deck with FRP bar proved to satisfy the requirements and to be structurally stable while showing the amount of crack and residual vertical displacement within the allowable limits after two million cyclic loadings. The structural failure of RC bridge deck is generally caused from the punching shear rather than moment. Therefore, the ultimate load at failure could be estimated using the shear strength formula in the two-way slab based on ACI and AASHTO criteria. However the design criteria tend to underestimate the shear strength since they don't consider the arching effects and nonlinear fracture in bridge deck with lateral confinement. In this paper, an equation to estimate the punching shear strength of steel strap deck is to be developed considering the actual failure geometries and effect of lateral confinement by strap while the results are verified in accordance with laboratory tests.

• Journal of Bio-Environment Control
• /
• v.1 no.2
• /
• pp.123-134
• /
• 1992

In order to verify the usability of the greenhouse for aquaculture with nutrient culture synchronously and to obtain the fundamental data fir the establishment of efficient farming technology, the characteristics of microclimate and the growth of leafy vegetables were examined. Tilapia averaged 428.6 g grew to 784 g(1.83 times) for 147 days from May 29 to Oct. 21 and fingerlings averaged 12.9 g grew by 1.37 times for 61 days from Sep. 13 to Nov. 12. The growth of vegetables such as water dropwort, leaf lettuce, Chinese cabbage, and Welsh onion in the greenhouse was better for aquaculture with nutrient culture than for nutrient culture only. Between above two greenhouses, pH and EC of nutrient solution was same but the temperature different by about 2$^{\circ}C$. Average day temperature, relative humidity, and $CO_2$ concentration were higher by 2.9$^{\circ}C$, 6%, and 200 ppm in the greenhouse for aquaculture with nutrient culture, respectively. Net assimilation rate of vegetables in the greenhouse was a little higher for aquaculture with nutrient culture than for nutrient culture only. Therefore, provided aquaculture and nutrient culture are carried out in the same greenhouse, the saving effect of heating cost as well as the additional promotive effects of vegetable and tilapia growth can be obtained.

• Journal of the Korean Geographical Society
• /
• v.48 no.5
• /
• pp.651-666
• /
• 2013

The objective of this study is to introduce the characteristics and establishing process of national regional policy for the sunbelt developmentr initiative of the southern coastal area in Korea. Discussion on the development of southern coastal area of Korea with some members of the Korea Society of Future Studies began in the early 1990s, and its discussion was continued with the activities by the Committee on Regional Unity of the Grand National Party and Namhaean Forum. The sunbelt development initiative was selected as one of the major commitments of the Grand National Party in the 17th presidential election of Korea. Since the launching of the Lee Myung-bak government, the Presidential Committee on Balanced National Development made a comprehensive plan for sunbelt development of southern coastal area(CPSD), and this plan was confirmed by central governmental planning in May 2010. CPSD is meaningful in terms of the fir first national regional planning and legal plan in Korea. The target year of CPSD is 2020, and some projects by CPSD started in 2010. However, there are many negative views that CPSD will not be going too well. Therefore, new efforts and roles of geographers who participated in the process of planning of CPSD are required for the success of CPSD.

• The Journal of Korean Academy of Prosthodontics
• /
• v.45 no.5
• /
• pp.675-686
• /
• 2007

Statement of problem: Titanium nitride(TiN) coatings are the most general and popular coating method and used to improve the properties of metallic surface for industrial purposes. When TiN coating applied to the abutment screw, frictional resistance would be reduced, as a results, the greater preload and prevention of the screw loosening could be expected. Purpose: The purpose of this study was to investigate mechanical properties of TiN coated film of various coating thickness on the titanium alloy surface and to evaluate proper coating thickness. Material and method: 95 Titanium alloy (Ti-6Al-4V) discs of 15 mm in diameter and 3 mm in thickness were prepared for TiN coating and divided into 7 groups in this study. Acceding to coating deposition time (CDT) with TiN by using Arc ion plating, were divided into 7 groups : Group A (CDT 30min), Group B (CDT 60min), Group C (CDT 90min), Group D (CDT 120min), Group E (CDT 150min), Group F(CDT 180min) and Group G (no CDT) as a control group. TiN coating surface was observed with Atomic Force Microscope(AFM), field emission scanning electron microscopy(FE-SEM) and examined with scratch tester, wear tester. Result: 1. Coating thickness fir each coated group was increased in proportion to coating deposition time. 2. Surface of all coated groups except Group A was homogeneous and smooth. However, surface of none coated Group G had scratch. 3. Adhesion strength for each coated group was increased in proportion to coating deposition time. 4. Wear resistance for each coated group was increased in proportion to coating deposition time. 5. Surface roughness in Group A, B, C was increased in proportion to coating deposition time. But, surface roughness in Group D, E, F was showed decreased tendency in proportion to coating deposition time. Conclusion: According to coating deposition time, mechanical properties of TiN coated film were changed. It was considered that 120 minutes coating deposition time ($1.32{\mu}m$ in coating thickness) is necessary.

• The Journal of Korean Medicine
• /
• v.28 no.1 s.69
• /
• pp.72-86
• /
• 2007

Objectives : The purpose of this study was to evaluate and compare the cost-effectiveness of Eastern, Western, and collaborative treatments and suggest a cost-effective approach for patients with frozen shoulder pain. Methods : Using the data of fifty-two patients, treatment effectiveness was measured by CSA, SPABI, and ROM scales and changes from the baseline score were evaluated. Data source for cost estimation was based on the national health insurance (NHI) payment system. Because the price in NHI was differentiated by health care institutions, five collaborative types were considered in assessing costs. Cost-effective ratios were computed for economic evaluation. Results : Compared with Eastern treatment, collaborative and Western treatments showed better effects on CSA scale after 4 weeks' treatment. The collaborative approach was also the most effective treatment on SPADI and ROM scales. The direct cost per patient receiving Eastern treatment was less than other treatments. In general, collaborative treatment dominated Eastern and Western treatments in cost-effectiveness an analysis. However, the cost-effectiveness ratio of Eastern treatment resulted in \9,000 compared to \29,000 of collaborative treatment on SPADI. Four different indicators of ROM scales resulted in different approaches as the cost-effective treatment. Conclusions : Considering cost-effectiveness ratios, collaborative treatment was the best treatment on CSh and SPADI scales after 4 weeks' treatment. As for ROM scales, the recommended alternatives were Eastern treatment for patients with abduction and adduction disabilities, Western treatment for those with flexion disability, and collaborative approach fir those with extension disabiliry.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.38 no.7
• /
• pp.455-463
• /
• 2001

In this Paper, an approximate processing method is proposed and tested. The proposed method uses variable CSD (VCSD) coefficients which approximate filter stopband attenuation by controlling the precision of the CSD coefficient sets. A decimation filter for Audio Codec '97 specifications has been designed having processor architecture that consists of program/data memory, arithmetic unit, energy/level decision, and sinc filter blocks, and fabricated with 0.6${\mu}{\textrm}{m}$ CMOS sea-of-gate technology. For the combined two halfband FIR filters in decimation filter, the number of addition operations were reduced to 63.5%, 35.7%, and 13.9%, compared to worst-case which is not an adaptive one. Experimental results show that the total power reduction rate of the filter is varying from 3.8 % to 9.0 % with respect to worst-case. The proposed approximate processing method using variable CSD coefficients is readily applicable to various kinds of filters and suitable, especially, for the speech and audio applications, like oversampling ADCs and DACs, filter banks, voice/audio codecs, etc.

• Journal of the Korean earth science society
• /
• v.26 no.8
• /
• pp.759-770
• /
• 2005

The purpose of this study is to examine the Earth science content relevance of the 7th national science curriculum. For this purpose, we (1) analyzed science curriculum or content standards of Korea, California, England and Japan, (2) compared science textbooks of Korea and Japan, (3) conducted a nationwide survey to gather opinions from students, teachers, professors and textbook authors about the relevance of the science curriculum and textbooks. According to the results, the Earth science contents of the 7th national science curriculum were not appropriate in terms of the objectives of science curriculum and the needs of students and society. The main reasons include the equal division among physics, chemistry, biology and earth science, iack of connection due to fractionation of units, overly strict application of spiral curriculum, and redundant amount of activities and concepts to cover in the textbook. Major suggestions fir securing the relevance of Earth science contents are as follows: First, the science contents and the size of units at each grade level should be determined according to the students' characteristics, not by equal portion rule. Second, the excessive overlapping and repetition of contents due to the spiral curriculum should be avoided. In addition, the number of activities should be reduced and the quality of required science activities should be improved. Third, to raise students' interest in Earth science, real-life applications and real-world Earth science contents should be emphasized including natural disasters, safety, universe and space exploration, and natural resources. Lastly, considering one of the relevance criteria is feasibility, supports for schools and science teachers are needed to realize the goal of the intended science curriculum.

• The Journal of Korean Academy of Prosthodontics
• /
• v.39 no.1
• /
• pp.84-95
• /
• 2001

Titanium is widely used in dentistry for its low density, high strength, fatigue resistance, corrosion resistance, and biocompatibility. But it has a tendency of surface damage under circumstance of friction and impact for its low hardness of the surface. Coating is one of methods fir increasing surface hardness. Its effect is to improve surface physical characteristics without change of titanium. Diamond-like carbon and titanium nitride are known for its high hardness of the surface. So that this study was aimed at the wear test and the cytotoxicity test of the commercially pure titanium and Ti-6Al-4V alloy which were deposited by diamond-like carbon film or titanium nitride film to acertain improvement of the surface hardness and the biocompatibility. A disk (25mm diameter, 2mm thickness) was made of commercially pure titanium and Ti-6Al-4V alloy and these substrates were deposited by diamond-like carbon film or titanium nitride film. Diamond-like carbon film was deposited by the method of radiofrequency plasma assisted chemical vapor deposition and titanium nitride film was deposited by the method of reactive arc ion plating. Then these substrates were tested about wear characteristics by the pin-on-disk type wear tester in which ruby ball was used as a wear causer under the load of 32N, The fracture cycles were measured by rotating the substrates until their films were fractured. The wear volume was measured after 150 cycles and 3,000 cycles using surface profiler. The cytotoxicity test was peformed by the method of the MTT assay. The results were as follows : 1. In the results of the wear volume test, commercially pure titanium and titanium alloy which were coated by diamond-like carbon film or titanium nitride aim had higher resistance against wear than the substrates which were not coated by any films (P<0.05). 2. In the results of the fracture cycle test and the wear volume test, diamond-like carbon film had higher resistance against wear than titanium nitride film (P<0.05). 3. In both coatings of diamond-like carbon aim and titanium nitride film, Ti-6Al-4V alloy had higher resistance against wear than commercially pure titanium (P<0.05) 4. In the results of the cytotoxicity test, diamond-like carbon film and titanium nitride film had little cytotoxicity as like commercially pure titanium or Ti-6Al-4V alloy (P>0.05).

• Journal of rehabilitation welfare engineering & assistive technology
• /
• v.7 no.1
• /
• pp.51-58
• /
• 2013

As it is changing into aging society, rehabilitation, welfare and sports industry markets are being expanded fast. Especially, the field of vital signals interface to control welfare instruments like wheelchair, rehabilitation ones like an artificial arm and leg and general electronic ones is a new technology field in the future. Also, this technology can help not only the handicapped, the old and the weak and the rehabilitation patients but also the general public in various application field. The commercial bio-signal measurement instruments and interface systems are complicated, expensive and large-scaled. So, there are a lot of limitations for using in real life with ease. this thesis proposes a wireless transmission interface system that uses EMG(electromyogram) signals and a control module to manipulate hardware systems with portable size. We have designed a hardware module that receives the EMG signals occurring at the time of wrist movement and eliminated noises with filter and amplified the signals effectively. DSP(Digital Signal Processor) chip of TMS320F2808 which was supplied from TI company was used for converting into digital signals from measured EMG signals and digital filtering. We also have used PCA(Principal Component Analysis) technique and classified into four motions which have right, left, up and down direction. This data was transmitted by wireless module in order to display at PC monitor. As a result, the developed system obtains recognition success ratio above 85% for four different motions. If the recognition ratio will be increased with more experiments. this implemented system using EMG wrist direction signals could be used to control various hardware systems.