• 한국인구학
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• 제3권1호
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• pp.52-61
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• 1979

The purpose of the study is to construct a life table for population. It is based on the fraction of last year of life, $a_X$. The data necessary for this purpose have been obtained from the 1975 Population Census Report of Korea and the Vital Statistics of Shindong-myon, Chunseong-gun, Gangwon Province which is collected for the Seoul National University public health program. Age specific death rate is adapted by the Model Life Table, West, Level 21. For the age groups of less than 5 years of age, when the record of vital events can be obtained, the fractions are calculated from the community vital statistics. And for the age groups older than 5 years of age, Greville's Method is used. The findings are summarized as follows: 1) The fraction of last year of life in infantile group is 0.3684 for males, 0.3711 for females, and in 1-4 years of age group 1.2164 for males, 1.2274 for females. Both are more than those of Japan and U.S. in 1963. 2) Infant mortality rate is 42.37 for males, 31.77 for females per 1,000 live births. 3) The mortality curves show that a higher rate is observed under 1 year of age. It drops to the lowest point at around 10 years of age and rises again as the age increases. 4) The age estimated half-survival rate is during the age group of 70-74 for both sexes. 5) Life expectancy at the age of 0 shows 65.73 years for males and 69.22 years for females.

• Journal of the Korean Wood Science and Technology
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• 제20권1호
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• pp.38-45
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• 1992

Fine and alkali-swollen structures of native cellulose fibers were investigated by x-ray diffraction methods. The results of fine structures are shown in Table 1. In meridional x-ray diffractograms, the relative intensity ratio R of (002) to (004) for cellulose I was ca. 0.05 and for regenerated cellulose it was ca. 0.45. It was considered that the transformation from cellulose I to cellulose II resulted from the packing or conformational change of cellulose chain. Finally. although cellulose I was not detected in the alkali-swollen celluloses treated for 1 hr to 24 hrs, washing and drying them resulted in the generation of considerable amounts of cellulose I and the amount decreased with increasing alkali duration.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.218-221
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• 2004

The electronic state of ZnO doped with Al, Ga and In, which belong to III family elements in periodic table, was calculated using the density functional theory. In this study, the program used for the calculation on theoretical structures of ZnO and doped ZnO was Vienna Ab-initio Simulation Package (VASP), which is a sort of pseudo potential method. The detail of electronic structure was obtained by the describe variational $X{\alpha}(DV-X{\alpha})$(DV-Xa) method, which is a sort of molecular orbital full potential method. The optimized crystal structures obtained by calculations were compared to the measured structure. The density of state and energy levels of dopant elements was shown and discussed in association with properties.

• 한국음향학회:학술대회논문집
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• 한국음향학회 2001년도 추계학술발표대회 논문집 제20권 2호
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• pp.129-132
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• 2001

본 논문에서는 EVRC 음성 부호화 시스템을 7MS320C54x를 이용하여 전 과정을 어셈블리어로 실시간 구현하였다. 구현된 EVRC 음성 부호화기는 최대의 계산량을 요구하는 8kbps 일때 잡음제거 알고리즘을 제치한 인코더부분이 평균 26.3MIPS 이며 디코더부분은 3.6MIPS의 복잡도를 나타낸다. 사용된 메모리양은 프로그램 ROM 16.9K words, 데이터 ROM(table) 7.9K words 및 RAM 5.8K words 이다. 구현된 EVRC 음성 부호화기는 북미 표준화 기구인 TIA(Telecommunications Industry Association)에서 제공하는 19 개의 테스트 백터들을 모두 통과하였다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2024년도 춘계학술발표대회
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• pp.381-382
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• 2024

Open RAN(Radio Access Network)을 선도적으로 연구하고 있는 O-RAN Alliance에서는 Open RAN의 E2 인터페이스에서 발생 가능한 보안 위협 중 하나로 MitM(Man-in-the-Middle) 공격을 명시하였다. 그러나 이에 대응하기 위한 보안 요구사항으로는 3계층 보안 프로토콜인 IPsec 사용을 명시하고 있으며, 2계층 공격인 ARP(Address Resolution Protocol) 스푸핑에 대한 요구사항은 명시하고 있지 않다. 따라서 본 논문에서는 MitM 공격 중 하나인 ARP 스푸핑으로부터 E2 인터페이스를 보호하기 위해, Near-RT RIC의 ARP 테이블에서 E2 인터페이스로 연결되는 장비에 대한 MAC 주소를 정적으로 설정할 수 있는 xApp을 제안한다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.245-246
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• 2006

For developing 5-axis laser cutting systems, many problems such as rotating of laser head or table, 5-axis tool path generation and collision avoidance between laser head and product should be solved. In this paper, a five-axis laser cutting machine with table swivel and rotary type configuration is developed. The five axes (X,Y,Z,A,B) are controlled and interfaced to PC via MMC board. Two kinds of CAM S/W such as commercial 5-axis CAM S/W(Euclid) and UG-API are engaged to generate NC code for the developed 5-axis laser cutting machine.

• 대한수학회보
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• 제22권2호
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• pp.121-126
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• 1985

D.K. Harrison [5] has shown that if R and S are fields of characteristic different from 2, then two Witt rings W(R) and W(S) are isomorphic if and only if W(R)/I(R)$^{3}$ and W(S)/I(S)$^{3}$ are isomorphic where I(R) and I(S) denote the fundamental ideals of W(R) and W(S) respectively. In [1], J.K. Arason and A. Pfister proved a corresponding result when the characteristics of R and S are 2, and, in [9], K.I. Mandelberg proved the result when R and S are commutative semi-local rings having 2 a unit. In this paper, we prove the result when R and S are 2-fold full rings. Throughout this paper, unless otherwise specified, we assume that R is a commutative ring having 2 a unit. A quadratic space (V, B, .phi.) over R is a finitely generated projective R-module V with a symmetric bilinear mapping B: V*V.rarw.R which is nondegenerate (i.e., the natural mapping V.rarw.Ho $m_{R}$ (V, R) induced by B is an isomorphism), and with a quadratic mapping .phi.:V.rarw.R such that B(x,y)=(.phi.(x+y)-.phi.(x)-.phi.(y))/2 and .phi.(rx)= $r^{2}$.phi.(x) for all x, y in V and r in R. We denote the group of multiplicative units of R by U(R). If (V, B, .phi.) is a free rank n quadratic space over R with an orthogonal basis { $x_{1}$, .., $x_{n}$}, we will write < $a_{1}$,.., $a_{n}$> for (V, B, .phi.) where the $a_{i}$=.phi.( $x_{i}$) are in U(R), and denote the space by the table [ $a_{ij}$ ] where $a_{ij}$ =B( $x_{i}$, $x_{j}$). In the case n=2 and B( $x_{1}$, $x_{2}$)=1/2, we reserve the notation [ $a_{11}$, $a_{22}$] for the space.the space.e.e.e.

• 대한수학회보
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• 제22권1호
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• pp.11-15
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• 1985

Manddelberg [9] has shown that a Clifford algebra of a free quadratic space over an arbitrary semi-local ring R in Brawer-Wall group BW(R) is determined by its rank, determinant, and Hasse invariant. In this paper, we prove a corresponding result when R is a full ring.Throughout this paper, unless otherwise specified, we assume that R is a commutative ring having 2 a unit. A quadratic space (V, B, .phi.) over R is a finitely generated projective R-module V with a symmetric bilinear mapping B: V*V.rarw.R which is non-degenerate (i.e., the natural mapping V.rarw.Ho $m_{R}$(V,R) induced by B is an isomorphism), and with a quadratic mapping .phi.: V.rarw.R such that B(x,y)=1/2(.phi.(x+y)-.phi.(x)-.phi.(y)) and .phi.(rx) = $r^{2}$.phi.(x) for all x, y in V and r in R. We denote the group of multiplicative units of R by U9R). If (V, B, .phi.) is a free rank n quadratic space over R with an orthogonal basis { $x_{1}$,.., $x_{n}$}, we will write < $a_{1}$,.., $a_{n}$> for (V, B, .phi.) where the $a_{i}$=.phi.( $x_{i}$) are in U(R), and denote the space by the table [ $a_{ij}$ ] where $a_{ij}$ =B( $x_{i}$, $x_{j}$). In the case n=2 and B( $x_{1}$, $x_{2}$)=1/2 we reserve the notation [a $a_{11}$, $a_{22}$] for the space. A commutative ring R having 2 a unit is called full [10] if for every triple $a_{1}$, $a_{2}$, $a_{3}$ of elements in R with ( $a_{1}$, $a_{2}$, $a_{3}$)=R, there is an element w in R such that $a_{1}$+ $a_{2}$w+ $a_{3}$ $w^{2}$=unit.TEX>=unit.t.t.t.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(4)
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• pp.41-44
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• 2001

Variable length coding (VLC) has been used in many well known standard video coding algorithms such as MPEG and H.26x. However, VLC can not be processed parallelly because of its sequentiality. This sequentiality is a big barrier for implementing a real-time software video codec since parallel schemes can not be applied. In this paper, we propose a new fast VLD (Variable Length Decoding) method based on the probabilistic distribution of symbols in VLC tables used in MPEG as well as H.263 standard codecs. Even though MPEG suggests the table partitioning method, they do not show theoretically why the number of partitioned tables is two or three. We suggest the method for deciding the number of partitioned tables. Applying our scheme to several well-known MPEG-2 test sequences, we can reduce the computational time up to about 10% without any sacrificing video quality

• 한국정밀공학회지
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• 제27권12호
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• pp.119-124
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• 2010

In this paper, thermal stabilization design of a new concept compact machining center has been investigated. A new concept machining center adopted a new X-axis as a NC rotary table. A New concept compact machining center is designed that spindle speed, feed rate and NC Rotary table speed are 12,000rpm, 60m/min and 110rpm each. The analysis is carried out by using FEM simulation Solidworks, CATIA and ANSYS. This paper is focused on the thermal deformation according to temperature distribution of a spindle system and feed drive system. Heat transfer analysis is performed according to heat source and atmosphere contact parts. As a result, this compact machining center is designed as a thermally stable structure.