• 한국학교수학회논문집
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• 제18권1호
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• pp.1-14
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• 2015

본 논문에서는 짝수와 홀수, 수의 합성과 분해, 받아올림과 받아내림이 각각 있는 (몇)+(몇), (십 몇)-(몇)과 관련된 지도 내용의 개선을 위해 ${\ll}$수학 1-1${\gg}$, ${\ll}$수학 1-2${\gg}$에서의 해당 지도 내용을 검토하였다. 이러한 검토를 통해 얻은 시사점은 다음 세 가지이다. 첫째, 짝수와 홀수의 정의를 재고할 필요가 있다. 또, ${\ll}$수학 1-1${\gg}$에서 짝수와 홀수를 취급하는 것이 합리적인지 재고할 필요가 있다. 둘째, 20 이하의 수의 합성 분해를 취급할 필요가 있다. 즉, 10을 기준으로 하여 '10과 (몇)으로 (십 몇)', '(십 몇)으로 10과 (몇)'이라는 합성 분해의 취급을 고려할 필요가 있다. 또, 10의 합성 분해를 (십 몇)의 합성 분해보다 먼저 취급하는 지도 순서를 고려할 필요가 있다. 셋째, 계산 과정에서의 논리적 비약을 해소할 필요가 있다. 즉, 받아올림이 있는 (몇)+(몇)과 받아내림이 있는 (십 몇)-(몇)의 계산에서 10을 기준으로 하여 '10과 (몇)으로 (십 몇)', '(십 몇)으로 10과 (몇)'이라는 수의 합성 분해의 사용을 고려할 필요가 있다. 또, 필산 형식의 지도에서 일관성을 유지할 필요가 있다.

• 한국수산과학회지
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• 제29권6호
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• pp.787-796
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• 1996

The biodegradation experiment, the TOD analysis and the element analysis for dispersant, Bunker-A oil and Bunker-B oil were conducted to study the biodegradation characteristics of a mixture of Bunker-A oil with dispersant and a mixture of Bunker-B oil with dispersant in the seawater. The results of biodegradation experiment showed 1mg of dispersant to be equivalent to 0.26 mg of $BOD_5$ and to 0.60 mg of $BOD_{20}$ in the natural seawater. The results of TOD analysis showed each 1 mg of dispersant, Bunker-A oil and Bunker-B oil to be equivalent to 2.37 mg, 2.94 mg and 2.74 mg of TOD, respectively. The results of element analysis showed carbon, hydrogen, nitrogen and phosphorus contents of dispersant to be $82.1\%,\;13.8\%,\;1.8\%\;and\;2.2\%$, respectively. Carbon and hydrogen contents of Bunker-A oil were found to be $73.3\%\;and\;13.5\%$, respectively, and carbon, hydrogen and nitrogen contents of Bunker-B oil to be $80.4\%,\;12.3\%\;and\;0.7\%$, respectively. Accordingly, the detection of nitrogen and phosphorus in dispersant shows that dispersants should be used with caution in coastal waters, with relation to eutrophication. The biodegradability of dispersant expressed as the ratio of $BOD_5/TOD$ was found to be $11.0\%$. As the mix ratios of dispersant to Bunker-A oil (3 mg/l) and a mixture of Bunker-B oil (3mg/l) were changed from 1 : 10 to 5 : 10, the biodegradabilities of a mixture of Bunker-A oil with dispersant and Bunker-B oil with dispersant increased from $2.1\%\;to\;7.2\%$ and from $1.0\%\;to\;4.4\%$, respectively. Accordingly, the dispersant belongs to the organic matter group of middle-biodegradability while mixtures in the mix ratio range of $1:10\~5:10$ belong to the organic matter group of low-biodegradability. The deoxygenation rate constant $(K_1)$ and ultimate biochemical oxygen demand $(L_0)$ obtained from the biodegradation experiment and Thomas slope method were found to be 0.125/day and 2.487 mg/l for dispersant (4 mg/l), respectively. $K_1\;and\;L_0$, were found to be $0.079\~0.131/day$ and $0.318\~2.052\;mg/l$ for a mixture of Bunker-A oil with dispersant and to be $0.106\~0.371/day$ and $0.262\~1.106\;mg/l$ for a mixture of Bunker-B oil with dispersant, respectively, having $1:10\~5:10$ mix ratios of dispersant to Bunker-A oil and Bunker-B oil. The ultimate biochemical oxygen demands of the mixtures increased as the mix ratio of dispersant to Bunker-A, B oils changed from 1 : 10 to 5 : 10. This suggests that the more dispersants are applied to the sea for the cleanup of Bunker-A oil or Bunker-B oil, the more decreases the dissolved oxygen level in the seawater.

• 한국광물학회지
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• 제24권3호
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• pp.179-188
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• 2011

북동태평양 우리나라 광구 KR5지역의 해서퇴적물 퇴적연대와 퇴적환경의 변화를 살펴보고자, 상자형 코아 시료에 대해 심도에 따른 Be 동위원소 분석을 실시하였다. 분석 코아 시료(BC08-02-13)는 상부에서부터 Facies I, Facies II, Facies III 세 개의 암상으로 구분된다. Facies I은 갈색/암갈색을 띠는 (10YR4/3) 균질한 머드로 높은 함수량을 보이는 것이 특징적이다. Facies II 는 갈황색을 띠고(10YR6/6), Facies I과는 부정합적인 관계를 보이며, Facies III는 암갈색을 띠는 머드층이다. Facies II과 FaciesIII 생교란작용에 의한 서관구조가 발달되어 있다. Be 연대측정 결과에 의하면 BC08-02-13 코아의 FaciesIII는 3.7 Ma 이전에 퇴적되었으며, Facies II 는 2.3 Ma 이전에 퇴적되었고, 그 후 환경변화에 의해 Facies II 상부가 침식을 받은 후 약 1.8 Ma 이후 현재까지 Facies I이 퇴적되었다. Facies I과 Facies II 경계의 부정합은 적도수렴대의 이동에 의한 환경변화에 의한 것으로 보인다.

• 한국화재소방학회논문지
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• 제31권2호
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• pp.82-88
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• 2017

소방특별조사의 성공적인 수행을 위해서는 인적 자원의 보완이 필요하다. 본 연구에서는 이에 대한 연구를 수행하였다. 추정한 결과 전체 대상물을 1년 안에 조사하기 위해서는 2인 1조를 기준으로 약 20,332명의 조사인원이 필요할 것으로 예측되었다. 5년 주기 전수조사를 목표로 한다면 1년에 20%씩 대상을 조사해야 한다. 현재로서는 모든 대상을 전부조사하기에는 인력이 부족하다. 인력의 부족은 부실조사의 원인이 된다. 그러므로 전부조사와 부분조사의 도입을 고려해야 할 것이다. 전부조사 10%와 부분조사 10%를 수행하는 경우, 총 2,734명이 필요한 것으로 나타났고, 전부조사 2%와 부분조사 18%를 수행하는 경우, 총 1,669명이 필요한 것으로 나타나고 있다.

• 대한치과기공학회지
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• 제10권1호
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• pp.25-41
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• 1988

In order to provide the National Dental Health Program with dasic data, and to implove the laborartory managent style, the author studied the operational situations of dental lads through questionaire. The results are as follows, 1. Unlicensured personnel should be replaced by the licensured(from present rate lf 49.2% licensured to more than80%) 2. Minimum wage guarantee system as well as well as oage raise should be established. 3. Monthly balancing accounts system and bepreciation reserve accounts system should be established for the reasonable management. 4. Manufacturing period should be elongated from presnt 2.8 days to 5-7 days for quality betterment of the processes. 5. Medical insurance system should be applied to the dental processes. 6. Manufacturing cost should be increased by 35%. 7. Retirement grants lr retirement annuity system, improvement of occupational environ-ment, and holidays incentives, and participation in medical insurance system should be adopted for the wellfare of the dental technicians. 8. Laboratory managers should operate the lads with pride and valuation. 9. Business Management course should be included in the curriculum of the dental labo-ratory school. 10. Good relationship between Korean Association of Dental Laboratory Technicians and local laboratories shorld be improved.

• Journal of Plant Biology
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• 제20권2호
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• pp.77-82
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• 1977

The inhibiotory effect of ethphon on the flowering in Lemna perpusilla 6746 was shown to be related to sucrose concentrations and dilution factors of Hutner's medium. When grown in 1/10-strength Hutner's medium under 10(14) cycles, the plants have been completely inhibited in the floral induction by ethephon (>5ppm) in the presence of sucrose (>20 mM) in the meduim. However, in a less diluted Hutner's medium (1/2-strength), the inhibition of flowering by ethephon was observed to be partially diminished by sucrose at a high concentration (30mM), while a low concentration of sucrose enhanced the inhibitory effect of ethephon in flowering. As inductive dark periodswere extended, the effects of both compounds were partially nullified. Since no significant amount of ethylene possibly released in ethephon decomposition in the medium was detected, the inhibitory effect of ethephon in flowering was postulated to be exerted only through ethylene production within the plants. Plants were incubated in 10 ppm ethephon-containing medium during either dark or light periods, singly or periodically. The most effective single treatment with ethephon was observed during the 4th dark period, when formation of floral stimulus was assumed to be completed beyond a critical level. This postulation can be partially supported by a fact that the plants should be exposed to at least more than four consecutive 10(14) cycles for flowering.

• 대한수의학회지
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• 제31권1호
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• pp.11-18
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• 1991

The purpose of this study was designed to investigate the methods for the functional elevations of sperm-host (utero-vaginal, U-V) glands in domestic hens. The laying hens were assigned to five groups of low-, medium-, high- fecundity, gonadotrophin-, and caffeinetreated hen groups, these group hens were sacrified at interval after last artificial inseminations (AI). Number of U-V gland observed in tissue preparation of each hen U-V region were investigated, and also the appearance rates of spermatozoa-contained U-V glands were calculated. 1. In low-fecundity hen groups, the appearance rates of spermatozoa-contained U-V glands were found to be 13.5, 15.6, 11.8, 13.6, 2.3, 0, and 0% respectively at the hens of 1, 3, 7, 10, 13, 16, and 19 days after AI. 2. In medium-fecunditiy hen groups, the appearance rates of spermatozoa-contained U-V glands were found to be 21.7, 22.7, 13.4, 10.4, 10.0, 7.7 and 0% respectively at the hens of 1, 3, 7, 10, 13, 16, and 19 days after AI. 3. In high-fecundity hen groups, the appearance rates of spermatozoa-contained U-V glands were found to be 30.8, 31.8, 28.9, 13.0, 10.3, 10.8, and 0.9 respectively at the hen of 1, 3, 7, 10, 13, 16, and 19 days after AI. 4. In gonadotrophin-treated hen groups, the appearance rates of spermatozoa-contained U-V glands were found to be 31.8, 33.7, 32.3, 17.3, 12.0, 5.0, and 1.0% respectively at hens of 1, 3, 7, 10, 13, 16, and 19 days after AI. 5. In caffeine-treated hen groups, the appearance rates of spermatozoa-contained U-V glands were found to be 33.2, 29.2, 22.4, 17.8, 12.7, 0, and 1.1% respectively at hens of 1, 3, 7, 10, 13, 16, and 19 days after AI. 6. The appearance rates of completely filled U-V glands and partially filled U-V glands of spermatozoa-contained U-V glands were found to be 3.8:1. So we suggested as follows: The appearance rates of spermatozoa-contained glands tend to be high from 1 day after AI to 7 days and tend to declined rapidly from 10 days. Also higher fecundity hen groups tend to be higher in the appearance rates and longer in spermatozoa-contained duration in U-V glands than in lower fecundity hen groups. Gonadotrophin hormone tend to increase the appearance rates of spermatozoa-contained U-V glands than those in control group, whereas caffeine tend to increase those rates at 1 day and to declined more rapidly from 3 day than in control group.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 추계학술대회 논문집
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• pp.272-276
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• 2001

Multicomponent $Zr_{41.2}Ti_{13.8}Cu_{12.5}Ni_{10}Be_{22.5}$ bulk matallic glass alloy shows good bulk glass forming ability due to its high resistance to crystallization in the undercooled liquid state.1) In this study, DSC and X-ray diffractometry have been performed to confirm the amorphous structure of the master $Zr_{41.2}Ti_{13.8}Cu_{12.5}Ni_{10}Be_{22.5}$ alloy. To investigate the mechanical properties and deformation behaviors of the bulk metallic $Zr_{41.2}Ti_{13.8}Cu_{12.5}Ni_{10}Be_{22.5}$ alloy, a series of compression tests has been carried out at the temperatures ranging from $351^{\circ}C$ to $461^{\circ}C$ and at the various initial strain rates from $2{\times}10^{-4}s^{-1}\;to\;2{\times}10^{-2}s^{-1}$. There are two types of nominal stress-strain curves. The one shows linear stress-strain relationship meaning fracture at maximum stress, the other shows plastic deformation including steady-state flow. Also DSC analysis for the compressed specimens has been performed to investigate the change of thermal stability and crystallization behavior for the various test conditions.

• 제어로봇시스템학회논문지
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• 제10권11호
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• pp.1065-1070
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• 2004

Optimal collision avoidance algorithm for unmanned aerial vehicles based on proportional navigation guidance law is investigated this paper. Although proportional navigation guidance law is widely used in missile guidance problems, it can be used in collision avoidance problem by guiding the relative velocity vector to collision avoidance vector. The optimal navigation coefficient can be obtained if an obstacle if an obstacle moves at constant velocity vector. The stability of the proposed algorithm is also investigated. The stability can be obtained by choosing a proper navigation coefficient.

• Structural Engineering and Mechanics
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• 제10권5호
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• pp.441-449
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• 2000

In this study, the state equation for axisymmetric bending of laminated transversely isotropic circular plates on elastic foundation is established on the basis of three-dimensional elasticity. By using the expansions of Bessel functions, an analytical solution of the problem is presented. As a result, all the fundamental equations of three-dimensional elasticity can be satisfied exactly and all the independent elastic constants can be fully taken into account. Furthermore, the continuity conditions at the interfaces of plies can also be satisfied.