• The Korean Journal of Zoology
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• v.4 no.1
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• pp.1-6
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• 1961

본 논문은 경기도광릉시험목에서 잣나무를 식해하는 한국미기록종 잣나무넓적잎벌(신칭)을 재료로 하여 1958-1961 년에 연구한 것을 기록한 것이다. (1) 본충은 막혈목 광요아목 편엽봉과의 Acantholyda nemoralis에 해당하는 것으로서, 이것의 학명으로는 R.B.Benson T의 설에 따라 Acantholyda posticalis posticalis MATSU.MURA를 채용하기로하였다. (2) 분포지로는 개지의 일본, 몽고, 시베리아 외에 한국을 추가한다. 구라파에서는 별개의 아종이 있다. 본종의 서식지로는 현재까지 경기도의 광fmd, 가평, 양주와 강원도의 충성군이 알려져있을 뿐이다. (3) 성충의 체색은 대체로 흑색이나, 두부와 훙부에 황색의 무늬가 많\ulcorner. 촉색은 황갈색 사상으로 유충은 웅충은 33절, 자충은 32절로 되었다. (4) 란은 QH트형으로 그 양단이 상외방으로 돌출, 산란직후의 색은 광택있는 담황갈색을 정하나 3일이 경과하면 담자황록색으로 변한다. 길이 약 3 mm , 폭 약 0.7mm이다. (5) 부화유충의 채색은 대적황색이나 , 머리와 흉곽은 흑색이다. 머리가 크고 몸통은 가늘다. 체장 약 3.5mm, 체폭 약 0.7mm. 성열유충의 체색은 담황갈색이나, 배선 및 기문상선은 선명한 적색이다. 3상의 흉곽과 한쌍의 미각이 있고, 망막은 없다. 두부는 키틴질화하였고, 갈색이며, 촉색은 7 절로되어 있고 대사가 발달하였다. 체장 약 27.4mm, 체폭 약 4.5mm , 전용은 적색의 배선 및 기문상선이 없고, 전신이 등황색이며, 촉색의 배측에 칠흑색의 커다란 복안을 가지고있는 점등이 성열유충과 다른 점이다. 암컷이 될 것은 크고 (체장 약 20-26mm), 수컷이 될 것은 작다(체장 약 3-17mm). (6) 용은 나용으로 용화직전의 것은 단지 복안과 단안만이 흑색을 정하고 , 타부분은 전부황색이지만 시간이 경과함에 따라 색이 변한다. 체장 약 17mm, 체폭 약 5mm.

• Journal of English Language & Literature
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• v.56 no.5
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• pp.773-796
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• 2010

This essay examines, first, the possibility and limitation of Asian America as a category of identity and its political and cultural implications through various theoretical perspectives. Here, by closely reading David Mura's poem "The Colors of Desire," I will argue that "Asian America" as a category of identity is now on the verge of falling apart and its politics of identity is no longer an effective way of fighting back against racism in the US. It is because Asian America is indeed what might be called a historical block, a product of ad-hoc coalition between different ethnic groups historically situated and constructed. In this sense, it is a kind of phantasmal object that is marked by practical absence. This fabricatedness inherent in Asian America as an identity category signifies that it has no essence that is meant to define the group in a transcendental way. The internal totality and coherence of that identity can thus be achieved only by suppressing differences between various ethnic groups and positing a single 'authentic' Asian American identity and culture. More dangerously, according to Viet Nguyen, such idealization of a single subject position can reinforces ideological rigidity that might threaten the ability of Asian America to represent itself in a unified fashion. Then, he predicts, Asian America will lose its cohesive force and fall apart. Eventually, every group within Asian America will be ethnicized. The only way of escaping from this bleak situation, as Vincent Cheng argues, is to foregroud the fabricatedness and ad-hocness of Asian America and to perform "inauthenticity," because Asian America is nothing but a functional category that is marked by absence of essence or authenticity. If Asian Americans admit that they have no essence and that they are essentially inauthentic, the practice of performing inauthenticity can become what we might call an alternative Asian American culture and identity.

• Progress in Medical Physics
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• v.19 no.4
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• pp.247-255
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• 2008

A coded aperture camera has been developed to improve the signal-to-noise ratio (SNR) while keeping the spatial resolution of a pinhole gamma camera. The purpose of this study was to optimize a coded aperture camera and to evaluate its possibility for thyroid imaging by Monte Carlo simulation. A clinical gamma camera, a pinhole collimator with 1.0 mm hole diameter, and a $79{\times}79$ modified uniformly redundant array (MURA) mask were designed using GATE (Geant4 Application for Tomographic Emission). The penetration ratio, spatial resolution, integral uniformity and signal-to-noise ratio (SNR) were simulated and evaluated as a function of the mask thickness. The spatial resolution of the coded aperture camera was consistent with the various mask thickness, SNR showed a maximum value at 1.2 mm mask thickness and integral uniformity was improved by increasing mask thickness. Compare to the pinhole gamma camera, the coded aperture camera showed improved SNR by a factor of 30 while keeping almost the same spatial resolution. In this simulation study, the results indicated that high spatial resolution and ultra-high SNR of the thyroid imaging are feasible using a coded aperture camera.

• Journal of Theoretical and Applied Mechanics
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• v.1 no.1
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• pp.69-88
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• 1995

The paper attempts to estimate the incubation time of a cavity in the interface between a power law creep particle and an elastic matrix subjected to a uniaxial stress. Since the power law creep particle is time dependent, the stresses in the interface relax. Through previous stress analysis related to the present physical model, the relaxation time is defined by ${\alpha}$2 which satisfies the equation $\Gamma$0 ｜1+${\alpha}$2k｜m=1-${\alpha}$2 [19]. $\Gamma$0=2(1/√3)1+m($\sigma$$\infty$/2${\mu}$)m($\sigma$0/$\sigma$$\infty$tm) where $\sigma$$\infty$ is an applied stress, ${\mu}$ is a shear modulus of a matrix, $\sigma$$\infty$ is a material constant of a power law particle, $\sigma$=$\sigma$0 $\varepsilon$ and t elapsed time. the volume free energy associated with Helmholtz free energy includes strain energies associated with Helmholtz free energy includes strain energies caused by applied stress anddislocations piled up in interface (DPI). The energy due to DPI is found by modifying the results of Dundurs and Mura[20]. The volume free energies caused by both applied stress and DPI are a function of the cavity size(${\gamma}$) and elapsed time(t) and arise from stress relaxation in the interface. Critical radius ${\gamma}$ and incubation time t to maximize Helmholtz free energy is found in present analysis. Also, kinetics of cavity fourmation are investigated using the results obtained by Riede[16]. The incubation time is defied in the analysis as the time required to satisfy both the thermodynamic and kinetic conditions. Through the analysis it is found that [1] strain energy caused by the applied stress does not contribute significantly to the thermodynamic and kinetic conditions of a cavity formation, 2) in order to satisfy both thermodynamic and kinetic conditions, critical radius ${\gamma}$ decreases or holds constant with increase of time until the kinetic condition(eq.40) is satisfied. Therefore the cavity may not grow right after it is formed, as postulated by Harris[11], and Ishida and Mclean[12], 3) the effects of strain rate exponent (m), material constant $\sigma$0, volume fraction of the particle to matrix(f) and particle size on the incubation time are estimated using material constants of the copper as matrix.