• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2015.07a
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• pp.1-2
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• 2015

본 논문에서는 ANC 시스템의 빠른 수렴을 위하여 2차 경로 필터를 초기화하는 방법을 제안한다. 대부분의 ANC 시스템에서는 2차 경로 필터를 설계하기 위하여 LMS 알고리즘을 사용한다. 그러나 기존의 방법들은 2차 경로 필터의 초기 계수 값을 0으로 설정하기 때문에 필터의 수렴 시간이 길어진다. 이를 해결하기 위하여 본 논문에서는 미리 구한 계수 값을 2차 경로 필터의 초기값으로 설정하여 필터의 수렴 시간을 줄이는 방법을 제안한다. 제안한 방법을 사용하면 2차 경로 필터의 초기 단계부터 에러가 작게 나타내며, 이에 따라 ANC 시스템의 수렴이 빨라진다. 상용 헤드셋을 이용하여 제안하는 방법을 실험하였으며, 기존 방법보다 빠르게 ANC 시스템이 수렴하는 것을 확인하였다.

• Journal of Korean Society of Steel Construction
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• v.21 no.6
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• pp.627-636
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• 2009

The purpose of this study was to evaluate the validity of the second-order analysis using the load amplification factor suggested by design codes. For this purpose, the first-order analysis with the B1 and B2 factors suggested by KBC 2005 and the direct analysis with the load amplification factor suggested by KBC 2009 (draft) were performed for three-story -one-bay and five-story-three-bay unbraced steel frames. The results of the analyses were compared with the results of the second-order inelastic analysis to evaluate the validity of the suggested methods. The main parameters of the analysis were the scale of the frame, the axial load ratio of the column, and the methods of analysis. The research results showedthat the method suggested by KBC 2005 does not properly consider the second-order effect under the high axial load ratio, but the direct analysis method suggested by KBC 2009 (draft) properly estimates the second-order effect without any serious problem.

• Journal of the Korean earth science society
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• v.34 no.4
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• pp.356-367
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• 2013

We study on the concept and reason of seasonal change that 164 university students have. Subsequently the concept types on the seasonal change are classified according to the characteristics and conceptual change after teaching on astronomy. All of the students were simply checked by the questionnaire of multiple choice and essay method before learning on the subjects. And then they answered to questionnaires of similar type after one semester. By the analyzed results, we classify it to three steps of hierarchical concept structure. The first step is the cosmic perspective that is related to the Earth's condition and motion. The second step is the influence of the Earth that is directly affected by the first step. The third step is observer's perspective on the Earth depending on the second step. Among the answers, the first step is prominent and second step is rare. The answers on the reason of seasonal change show some kinds of type which are 1st, 1-2nd, 1-3rd, and 1-2-3rd step. By the result, it is arranged in sequence like as 1-3rd>1st>1-2nd>1-2-3rd type. The lowest number of students was 2nd step of the Sun's altitude and duration of daytime in pre-test. However the students of 2nd step obtained more correct scientific concept on the seasonal change after learning on the subjects, and got the higher score in the post-test than in the pre-test. We found how much important the hierarchical structure on the reason of seasonal change is. As the results, second step on the learning of the Sun's altitude and duration of daytime essentially have to teach after first step. And then third step have to teach. At last, it is sure that the students can obtain the concept of seasonal change.

• Fire Science and Engineering
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• v.17 no.1
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• pp.26-32
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• 2003

Inert gases, Af, $N_2$, $CO_2$, as a Halon alternative, the empirical equations were correlated in terms of saturated pressure, density and viscosity, They were obtained by regression analysis from the experimental data in the literature. The empirical equations of saturated pressure were expressed as the second and third order function of temperature. The empirical equation for Ar and $N_2$ of density were expressed as the first order function of temperature. And $CO_2$ was expressed as the second and third order function of temperature. The empirical equation of viscosity was formulated as a power function with temperature. This empirical equations would allow us to predict pure component state.

• Journal of Animal Science and Technology
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• v.44 no.5
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• pp.523-530
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• 2002

Repeatabilities and Correlations among Average Daily Gain, Backfat Thickness and Lean Percent in Swine The repeatability, correlation and rank correlation coefficients among average daily gain, backfat thickness and lean percent were estimated on the basis of records tested from August 1999 to February 2000 with 695 pigs of Duroc, Landrace and Yorkshire boars and gilts tested at 2nd Korea Swine Test Station located in Ha-dong, Kyeongnam Province. The effect of the sex, breed and month of measured were estimated by the least square method. The repeatabilities were estimated from the component of variance among repeated measurements of the trait for the same animal. The results obtained are summarized as follow ; 1. The means of the major economic traits studied were 142.1 days, 173.7 days and 182.5 days for age at 1st, 2nd and 3rd measure, 57.9%, 56.2% and 55.2% for lean percent at 1st, 2nd and 3rd measure, 1.33cm, 1.61cm and 1.63cm for backfat thickness at 1st, 2nd and 3rd measure, 946.6g, 879.2g and 879.4g for average daily gain at 1st, 2nd and 3rd measure, respectively. 2. The correlation coefficients between the backfat thicknesses measured at 1st and 2nd, at 2nd and 3rd, at 1st and 3rd were 0.424, 0.700 and 1.424, respectively. The correlation coefficients between the lean percent measured at 1st and 2nd, at 2nd and 3rd, at 1st and 3rd were 0.493, 0.619 and 0.471, respectively. The correlation coefficients between the average daily gain measured at 1st and 2nd, at 2nd and 3rd, at 1st and 3rd were 0.716, 0.861 and 0.601, respectively. 3. The rank correlation coefficients between backfat thickness measured at 1st and 2nd, at 2nd and 3rd, at 1st and 3rd were 0.438, 0.693 and 0.441, respectively. The rank correlation coefficients between lean percent measured at 1st and 2nd, at 2nd and 3rd, at 1st and 3rd were 0.508, 0.593 and 0.478, respectively. The rank correlation coefficients between average daily gain measured at 1st and 2nd, at 2nd and 3rd, at 1st and 3rd were 0.704, 0.834 and 0.571, respectively. 4. The estimated repeatabilities of the traits studied were 0.428 for the lean percent, 0.374 for the backfat thickness and 0.673 for the average daily gain, respectively.

• Journal of Sericultural and Entomological Science
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• v.16 no.1
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• pp.77-84
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• 1974

In autumn season residual period of nicotine is observed in the larval duration, weight of molting larvae at the various stages, percentage of delayed molting larvae, and survival rate up to the 3rd stage from the 1st season to the 3rd season and up to the stage for four seasons, respectively. Mulberry tree is planted in pot from June 18, 1973 to August 4, 1973 and placed every other row between tobacco variety of Hicks cultivated in mulching system and control is prepared in the Sericultural Experiment Station, placing in the every ridge of mulberry field with the four seasons ; 5 day isolation (1st season), 15 day isolation (2nd season), 25 day isolation (3rd season), and 50 day isolation (4th season). 1) 1st and 3nd instar larvae fed with the tobacco stained mulberry leaf has longer larval duration for the four seasons, as compared with those of the control, increasing 12％ in index with 28 hours, 17％ in index with 37 hours, 23％ in index with 50 hours, 17％ in index with 43 hours from the 1st season to the fourth season and the 3rd to the 4th instar larvae, increasing 18％ in index with 55 hours. 2) 2nd instar molting larvae, 3rd instar molting larvae from the 1st to the 4th season and 4th instar molting larvae at the 4th season decrease their larval weight respectively, as compared with the control. 3) Percentage of delayed molting larvae from the 3rd stage to the 4th stage goes up higher than that of the control in the End larval stage at the 3rd to the 4th season, in the 3rd larval stage at the 1st, the End, and the 4th season, and in the 4th larval stage at the 4th season, respectively. 4) Survival rates in the 2nd larval stage at the 2nd season to the 4th season, in the 3rd larval stage at the 1st to the 4th season, and in the 4th larval stage at the 4th season respectively are higher than that in the control.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.133-139
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• 2009

1) 공시유기질비료의 전질소는 유기발효돈분(2.68 %) > 계분부산물퇴비(1.97 %) > 유기발효계분, 돈분부산물퇴비(1.92 %) > 유기퇴적우분(1.12 %) > 유기 생 우분(1.04 %) 순이었다. 또한 유기물 함량은 유기 생 우분(81.73 %) > 유기퇴적우분(75.52 %) > 계분부산물(68.25 %) > 유기발효돈분(63.37 %) > 돈분부산물(45.27 %) > 유기발효계분(32.05 %) 순이었다. 2) 수수$\times$수단그라스 교잡종의 건물수량은 1차에서는 유기발효계분(11.60 ton/ha)이 가장 많았으나 계분부산물퇴비(10.13 ton/ha), 돈분부산물퇴비(9.07 ton/ha)와의 유의차는 없었고, 2차 역시 유기발효계분(8.00 ton/ha)이 가장 많았으나 계분부산물퇴비(6.27 ton/ha), 돈분부산물퇴비(6.13 ton/ha)와의 유의차는 없었다(p<0.05). 3) CP 수량은 1차에서는 유기발효계분(0.69 ton/ha)이 가장 많았으나 돈분부산물퇴비(0.56 ton/ha), 계분부산물퇴비(0.55 ton/ha), 유기 생 우분(0.55 ton/ha)과의 유의차는 없었고, 2차에서는 유의차가 없었다(p<0.05). 4) TDN 수량은 1차에서는 유기발효계분(6.51 ton/ha)이 가장 많았으나 계분부산물 퇴비(5.80 ton/ha), 돈분부산물퇴비(5.08 ton/ha)와의 유의차는 없었고, 2차 역시 유기발효계분(4.80 ton/ha)이 가장 많이 나왔으나, 계분부산물퇴비(3.70 ton/ha)와 유의차는 없었다(p<0.05). 5) 상대사료가치(RFV)는 1차에서는 계분부산물퇴비 시비구가 80.66으로 유의하게 높았으나, 2차에서는 유기퇴적우분을 제외한 5개 시비구의 유의차는 없었다(p<0.05). 6) K는 유기발효계분(0.11 head/ha/yr)이 가장 높았으나 계분부산물퇴비(0.10 head/ha/yr), 돈분부산물퇴비(0.09 head/ha/yr)와 유의차는 없었고, $K_{CP}$ 역시 유기발효계분(7.23 head/ha/yr)이 가장 높게 나왔으나 돈분부산물퇴비(6.41 head/ha/yr), 유기 생 우분(6.15 head/ha/yr), 계분부산물퇴비(5.97 head/ha/yr)와의 유의차는 없었다(p<0.05). 또한 KTDN은 유기발효계분(8.90 head/ha/yr)이 가장 높게 나왔으나 계분부산물퇴비(7.49 head/ha/yr)와 유의차는 없었다(p<0.05). 7) 이상의 결과로 보았을 때, 유기발효계분이 수단그라스의 생산성, 사료가치 및 가축사육능력에서 가장 우수할 것으로 판단된다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.5 no.2
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• pp.94-100
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• 1981

McClintock 와 Walsh 의 개념을 발전시키므로써 2차와 3차계에서의 열적 기계적 파괴 기준식을 구하였다. Griffith Theory 와 파괴역학에 기초를 두고서 전개된 응력세기 인수로만 표기된 2차와 3차계의 파괴기준식은 동일한 관계식 즉, ( $k_{2}$/ $k_{2c}$ )$^{2}$+ $k_{1}$/ $k_{1c}$ =1로 표시된다는 것을 보였다. 3차계에서 열적 기계적 하중하에서 응역세기 인수에 관한 일반식을 Crack 의 닫힘을 고려하여 유도하였다.

• Review of KIISC
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• v.12 no.4
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• pp.1-10
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• 2002

SC27의 WG2는 정보기술보안을 위한 관련 메커니즘들에 대한 표준을 만드는 Working Group이다. 본 고에서 소개하는 24차 베를린회의(2002. 4) 이전에 개최된 21차 동경회의(2000. 10)와 22차 오슬로회의(2001. 4)는 동 학회지 제11권 1호(2001년 2월)와 제11권 3호(2001년 6월)클 참고하면 본 고를 이해함에 있어 많은 도움이 될 것으로 사료된다. 한편 23차 서울회의에 대하여는 WG2 중 블록암호 표준화 동향에 대하여 기고한 제11권 6호(2001년 12월)를 참고로 하기 바란다. 본 고에서는 지난 2002. 4. 22(월)∼26(금)에 걸쳐 독일 베를린의 DIN(Deutsches Institut fur Normung)에서 개최된 24차 회의에 다녀와서 보안기술 표준화에 관한 최신 정보를 이 분야에 관심이 있는 전문가들에게 전파하고자 각 과제별로 진행사항과 회의결과 및 회의 중 특기 할만한 사항들을 정리하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2014.06a
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• pp.211-214
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• 2014

본 논문에서는 정보통신미디어계열 학과로서 서울 소재 고등학교 2 학년 학생들을 대상으로 고교-대학 연계 프로그램을 진행한 경험을 분석하였다. 1 차와 2 차로 나누어 진행하였고, 1 차에서는 이론특강과 실습을 통해 최신이론을 학습하고, 기초적인 실습을 하였으며, 2 차에서는 심화실습을 통해 학생들의 문제해결능력과 발전가능성을 가늠해보았다. 1 차에서 학생들은 이론과 실습을 흥미로워 하였으나 난이도에 대한 체감이 달랐고, 2 차에서는 협업하여 결과물을 도출하였고 전체적인 만족도가 높게 나타났다. 결과적으로 직접 하는 실습을 선호하였고, 진로와 전공 탐색에 도움이 되었다고 평가하였으며, 관련 분야로의 학습 의욕이 있음을 나타냈다. 본 경험을 통해 학생들이 이러한 연계프로그램에서 만족하는 것과 원하는 것이 무엇인지를 분석하여 지속적이고 체계적인 고교-대학 연계 프로그램 개발에 도움이 되고자 하는데 의의가 있다.