• Title/Summary/Keyword: Field release

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Effects of Slow-release Nitrogen Fertilizers on Yield and Nitrogen Uptake of IR667 (IR667의 수량(收量) 및 질소흡수(窒素吸收)에 미치는 완효성 질소비종별(窒素肥種別) 효과)

  • Kwon, Hang Gwang;Park, Hoon;Park, Young Sun
    • Korean Journal of Soil Science and Fertilizer
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    • v.6 no.4
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    • pp.213-219
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    • 1973
  • Effects of three slow-release nitrogen fertilizers (Sulfur-coated urea, (SCU) Jin Hae Chemical Co. Korea(JHC); Tennessee Valley Authority. U.S.A(TVA); METAP, Japan) on the yield and nitrogen uptake of IR667 (Suwon 213) were investigated comparing with urea split application under the field condition with early and usual saeson cultivation. 1. SCU(JHC) was not superior than urea split application in yield and nitrogen nutrition due to early release of nitrogen. 2. SCU(TVA) outyielded urea split by 10% showed always highest nitrogen content in straw and most balanced relative cumulative curve of nitrogen uptake or dry matter yield. 3. At ear formation stage SCU(TVA) showed specially high nitrogen content which was highly correlated with number of grain per $m^2$ of field. 4. Only SCU(TVA) showed one peak curve of nitrogen uptake rate at ear formation stage while others showed two peak pattern. 5. nitrogen fertilizer recovery of slow-release fertilizers was higher than urea split in early season cultivation and SCU (TVA) (46.0) was higher but SCU(JHC) (38.9) was similar in compare with urea split(37.1) in usual season cultivation. 6. Most promising slow-release nitrogen to match plant requirement seems to be one mixed of various slow-release fertilizers having different release pattern.

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Central Crack in a Piezoelectric Disc

  • Kwon, Jong-Ho
    • Journal of Mechanical Science and Technology
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    • v.18 no.9
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    • pp.1549-1558
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    • 2004
  • This study is concerned with the general solution of the field intensity factors and energy release rate for a Griffith crack in a piezoelectric ceramic of finite radius under combined anti-plane mechanical and in-plane electrical loading. Both electrically continuous and impermeable crack surface conditions are considered. Employing Mellin transforms and Fourier series, the problem is reduced to dual integral forms. The solution to the resulting expressions is expressed in terms of Fredholm integral equation of the second kind. The solutions are provided to study the influence of the crack length, the crack surface boundary conditions on the intensity factors and the energy release rate.

Optimal Release Policy for a Software System using Number of Software Test (소프트웨어의 테스트 회수(回數)를 이용한 최적방출정책(最適放出政策))

  • Go, Hyeon-U;Hwang, Ui-Cheol
    • Journal of Korean Society for Quality Management
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    • v.17 no.2
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    • pp.27-35
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    • 1989
  • Software developers often allocate a significant amount of effort to software testing. But for most business-related software system it is natural to expect the continued discovery of defects after the software system is released into field. Such defects are usually very expensive to fix and have the potential to cause great damages to the users. It is important to stop testing the software and release it to the users at the correct time. In this paper, we propose the determination of the optimal number of software test oy minimizing a total expected software cost. A numerical example is used when the criterion is the expected profit. The result indicates that the proposed software release policy based on the number of software test can be a good alternative to the existing policy.

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Effect of initial coating crack on the mechanical performance of surface-coated zircaloy cladding

  • Xu, Ze;Liu, Yulan;Wang, Biao
    • Nuclear Engineering and Technology
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    • v.53 no.4
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    • pp.1250-1258
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    • 2021
  • In this paper, the mechanical performance of cracked surface-coated Zircaloy cladding, which has different coating materials, coating thicknesses and initial crack lengths, has been investigated. By analyzing the stress field near the crack tip, the safety zone range of initial crack length has been decided. In order to determine whether the crack can propagate along the radial (r) or axial (z) directions, the energy release rate has been calculated. By comparing the energy release rate with fracture toughness of materials, we can divide the initial crack lengths into three zones: safety zone, discussion zone and danger zone. The results show that Cr is suitable coating material for the cladding with a thin coating while Fe-Cr-Al have a better fracture mechanical performance in the cladding with thick coating. The Si-coated and SiC-coated claddings are suitable for reactors with low power fuel elements. Conclusions in this paper can provide reference and guidance for the cladding design of nuclear fuel elements.

Effect of Phosphate Coated Slow Release Fertilizer on Yield of Directly Seeded Rice (벼 건답(乾畓) 직파(直播) 재배(栽培)시 인산(燐酸)입힌 완효성(緩效性) 비료(肥料)의 시용효과(施用效果))

  • Jung, Yeong-Sang;Lee, Ho-Jin;Ha, Sang-Keun;Cho, Byung-Ok
    • Korean Journal of Soil Science and Fertilizer
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    • v.30 no.2
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    • pp.108-113
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    • 1997
  • A field experiment was conducted to evaluate effect of phosphate coated slow release fertilizer on the directly seeded rice. Odae byeo was seeded by drill under dry condition. The soil was a sandy clay loam soil located in the Experimental Farm of the Kangweon National University, Chuncheon, Kangweon-Do. The yield of rice from the urea applicated directly seeded field was 84.9% of the yield from the transplanted field, and showed no difference between split application treatments. The yield from the phosphate coated slow release fertilizer was the highest showing 110.7% of the yield from the urea application. The yield from the polymer coated slow release fertilizer was 90.4%. The yield from the organic fertilizer 400kg/10a treatment was 81.8% and was 94.8% from the organic fertilizer 600kg/10a treatment. In 1996 experiment, the yield from the phosphate coated slow release fertilizer was higher than the yield from the transplanted field. The $NO_3-N$ and $NH_4-N$ concentrations in soil solution at the depth of 15cm revealed that nitrogen leaching was the highest from the urea N40-0-30-30 treatment, and the lowest from the phosphate coated slow release fertilizer. The phosphorus concentration showed similar pattern. Therefore, use of phosphate coated slow release fertilizer increased rice yield and decreased loss of nitrogen and phosphorus loss.

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Field testing of a seismically isolated concrete bridge

  • Chang, K.C.;Tsai, M.H.;Hwang, J.S.;Wei, S.S.
    • Structural Engineering and Mechanics
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    • v.16 no.3
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    • pp.241-257
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    • 2003
  • The first seismically isolated structure in Taiwan was completed in early 1999. Seven new bridges of the Second National Freeway located at Bai-Ho area, a region which is considered to be of high seismic risk, have been designed and constructed with lead-rubber seismic isolation bearings. Since this is the first application of seismic isolation method to the practical construction in Taiwan, field tests were conducted for one of the seven bridges to evaluate the assumptions and uncertainties in the design and construction. The test program is composed of ambient vibration tests, forced vibration tests, and free vibration tests. For the free vibration tests, a special test setup composed of four 1000 kN hydraulic jacks and a quick-release mechanism was designed to perform the function of push-and-quick release. Valuable results have been obtained based on the correlation between measured and analytical data so that the analytical model can be calibrated. Based on the analytical correlation, it is concluded that the dynamic characteristics and free vibration behavior of the isolated bridge can be well captured when the nonlinear properties of the bearings are properly considered in the modeling.

Status of Conducting the Field Trip in the Middle and High School Science (중등학교 과학과 야외활동의 실태 및 개선 방안)

  • Hong, Jeong-Soo;Chang, Nam-Kee
    • Journal of The Korean Association For Science Education
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    • v.17 no.1
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    • pp.85-92
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    • 1997
  • The field is a good learning environment that offers many opportunities. Status of conducting field trip in the middle and high school was investigated As a result, there was few teachers who disagree that a course in science should include learning in the field. Yet, on practical side, teachers who used to conduct the field trip over once a year in science class appeared to be about 23% only. Most of schools conducting field trips hadn't well-planned program for instructional activities. Many of teachers appealed that they should not get release time for conducting an extended field experiences, and that they could not obtained good information in relation to the contents, the methods and strategies of field activities. It says that a good field trip needs administrative and financial surport, many informations, and the teacher's exertion.

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Connection of Myofascial Release to Cupping (근막이완술과 부항의 접목)

  • Baek Seung-Ryong;Chung Hyung-Kuk;Bae Sung-Soo
    • The Journal of Korean Physical Therapy
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    • v.8 no.1
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    • pp.109-119
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    • 1996
  • Although the physical therapy of both East and West has been based on an identical philosophy, they have had their own therapy with difference in its form and pattern. In general, cupping is used to diagnose and treat viscera by means of acupuncture point, and myofascial release is also used for both diagnosis and orthopedic treatment on the basis of trigger point and myofascial however, when they have a lot of identical facts such as using both mental and physical aspects of human beings for treatment, keeping nervous action balanced, and recovering depressed nervous functions and relieving the pain. In addition. their identical fact includes that they tend to treat patients by using symptoms and reaction shown in their skin, and that both East and West try to consider myofascia as an integrated totality and as a unified body of organic functions with correlations. Among the principles of myofascial release, recently, it has been very identical that stimulus given to the skin results in synapse to sympathetic nerve through dosal horn cell has an effect on viscera, and that cupping is sued for diagnosis and treatment of viscera. It is required, therefore, to continue to carry out studying on this field.

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