• The Korean Journal of Nuclear Medicine
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• v.39 no.6
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• pp.481-488
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• 2005

Purpose: Functional imaging of dopamine transporter (DAT) defines integrity of the dopaminergic system, and DAT is the target site of drugs of abuse such as cocaine and methamphetamine. Functional imaging the DAT may be a sensitive and selective indicator of neurotoxic change by the drug. The aim of the present study is to evaluate the clinical implications of qualitative/quantitative analyses of dopamine transporter imaging in methamphetamine abusers. Materials and Methods: Six detoxified methamphetamine abusers (abuser group) and 4 volunteers (control group) were enrolled in this study. Brain MRI was performed in all of abuser group. Abuser group underwent psychiatric and depression assessment using brief psychiatric rating scale (BPRS) and Hamilton depression rating scale (HAMD), respectively. All of the subjects underwent I-123 IPT SPECT (IPT SPECT). IPT SPECT image was analysed with visual qualitative method and quantitative method using basal ganglia dopamine transporter (DAT) specific/non-specific binding ratio (SBR). Comparison of DAT SBR between abuser and control groups was performed. We also performed correlation tests between psychiatric and depression assessment results and DAT SBR in abuser group. Results: All of abuser group showed normal MRI finding, but had residual psychiatric and depressive symptoms, and psychiatric and depressive symptom scores were exactly correlated (r=1.0, p=0.005) each other. Five of them showed abnormal finding on qualitative visual I-123 IPT SPECT Abuser group had lower basal ganglia DAT SBR than that of control ($2.38{\pm}0.20\;vs\;3.04{\pm}0.27$, p=0.000). Psychiatric and depressive symptoms were negatively well correlated with basal ganglia DAT SBR (r=-0.908, p=0.012, r=-0.924, p=0.009). Conclusion: These results suggest that dopamine transporter imaging using I-123 IPT SPECT may be used to evaluate dopaminergic system of the basal ganglia and the clinical status in methamphetamine abusers.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.1
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• pp.1-7
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• 2011

In this paper, based on an isogeometric approach, we have developed a shape design optimization method for plane elasticity problems subjected to design-dependent loads. The conventional shape optimization using the finite element method has some difficulties in the parameterization of geometry. In an isogeometric analysis, however, the geometric properties are already embedded in the B-spline basis functions and control points so that it has potential capability to overcome the aforementioned difficulties. The solution space for the response analysis can be represented in terms of the same NURBS basis functions to represent the geometry, which yields a precise analysis model that exactly represents the normal and curvature depending on the applied loads. A continuum-based isogeometric adjoint sensitivity is extensively derived for the plane elasticity problems under the design-dependent loads. Through some numerical examples, the developed isogeometric sensitivity analysis method is verified to show excellent agreement with finite difference sensitivity.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.10 no.2
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• pp.76-81
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• 1985

This paper presents basis functions for curvilinear square elements and describes finite element analysis for coaxial cable and coaxial cross-section waveguide. On the case of coaxial cable, the more exact results is obtained by the propotional elements than by the equal elements with the same number of elements. It is found that the cutoff frequency of coaxial cross-sectional waveguide is more dependent on the inner and outer radius than the cross-sectional angle.

• Electronics and Telecommunications Trends
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• v.28 no.3
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• pp.106-114
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• 2013

과거 이동통신용 기지국은 기저대역 처리부와 안테나를 포함하는 RF부가 일체형으로 제작되었으나, 4세대 이동통신에서는 기술/경제적인 이유로 BBU(Base Band Unit)와 RRH(Remote Radio Head)로 분리하여 구성되는 분산형 기지국 구조를 택하는 추세이다. BBU와 RRH 간 인터페이스로 널리 사용되어온 OBSAI, CPRI외에 2010년 ORI가 출현하여 표준화가 한창이다. ORI는 시장에서 널리 사용되는 CPRI(Common Public Radio Interface)의 Vendor Specific 부분으로 인해 제조사간 호환성이 보장되기 어려운 문제를 보완하기 위하여 탄생한 인터페이스 규격으로써, CPRI를 기반으로 하면서 표준으로써의 완성도를 높인 표준이라 할 수 있다. 또한 관련 표준으로는 유일하게 IQ 데이터 압축알고리즘의 표준화를 고려하고 있다. 본고에서는 ORI의 표준화 현황과 기술적인 이슈를 소개하고, 국내의 대응 현황을 알아본다.

• The Korean Journal of Zoology
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• v.37 no.1
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• pp.1-11
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• 1994

임신 26주, 27주의 생명력이 없는 한국인 태아 2예를 대상으로 십이지장 점막에서의 장내분비세포군집(일부 일본인 학자들이 명명한 "Segi's cap")의 출현, 형태 및 구조를 관찰하고. 이들 세포군집에서 내분비세포들의 존재 및 면역조직 화학적 특징들을 관찰하고자, 파라핀조직절편과 냉동박절 후 hematoxvlin과 eosin염색. Azan염색, Comori법, 그리고 면역조직화학염색 표본을 제작, 관찰하여 다음과 같은 결과들을 얻었다 세포들의 군집 형태는 장 내강을 향해서는 오목한 형태였고, 기저막을 향해서는 볼록한 형태였다. 군집을 이룬 세포들은 중층을 이루었고. 술잔세포도 장 내캉목에서 관찰되었다 또한. 내강쪽에 위치한 세포들의 경우 미세융모들의 줄무의가장자리는 관찰되지 않았다 Leuenkephalin, somatostatin, substance p, vasoactive intestinal polypeptide 및 5-HT 항혈청을 이용하여 면역조직염색한 결과 somatostatin 양성반응세포와 5-HT 양성반응세포만이 관찰되었다. 이들 somatostatin 양성반응 세포와 5-HT 양성반응세포들은 대개가 원추형의 세포들로서 개구형을 이루고 있음을 관찰한 수 있었다.관찰한 수 있었다.

• The Korean Journal of Zoology
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• v.38 no.1
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• pp.38-47
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• 1995

담수에서 해수로 이동하는 동안 환경의 변화에 적응하는 표피의 점액세포와 곤봉상세포의 구조적 기능적 적응기작을 연구하기 위하여 성숙한 뱀장어를 이용하여 본 실험을 행하였다. 높은 염농도로 외부환경이 변화함에 따라 뱀장어의 점액세포와 곤봉상세 포에서 능동적으로 대응하는 여러 현상들이 나타났다 포피전층에 점액세포의 수가 증가하였으며, 점액세포내에서의 세포소기 관이 활성화 되어 활발히 표피외분비를 하는 것이 관찰되었으며, 기저상피세포층과의 경계부위에서 나타나는 미성숙형 점액세포가 성숙형으로 바뀌는 현상이 나타나는 것으로 보아 표피의 점액질량을 증가시키는 것을 알 수 있었다 그리고 곤봉상세포에서도 염분증가에 따라 세포소기 관의 발달을 관찰할 수 있었으며, 중심포에서의 전자염색성의 변화와 함께 집합소포의 수가 증가하며, 중심포가 세분화되어 크기가 작아지는 현상을 관찰하고 그 기능적 의의에 대하여 논의하였다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.07a
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• pp.283-284
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• 2020

라즈베리파이는 교육용 프로젝트의 일환으로 개발된 임베디드 보드로서 모듈 확장성이 용이하여 사용자가 원하는대로 용도를 변경하거나 기능을 확장할 수 있다. 현재 한국 소프트웨어 교육은 프로그래밍 언어와 이론 위주의 경향이 짙은데, 이는 초기 학생들의 프로그래밍에 대한 흥미를 저하시키는 데 가장 큰 걸림돌이 되고 있다. 본 논문에서는 라즈베리파이를 활용하여 사물인터넷의 대표적 입력수단으로 활용되고 있는 음성인식을 구현하는 방법에 대해 논한다. 또한 향후에는 TPU(Tensor Processing Unit)의 전용 소프트웨어를 사용하여 대용량의 실시간 음성인식을 GPU를 이용하여 구현함으로써 실제 물리적인 장치들을 프로그래밍으로 제어함으로써 소프트웨어의 현실 통제 가능성을 직접 체험하여 음성인식뿐만 아니라 동작 원리 및 기저 기술들에 대한 관심을 불러일으키는 하나의 좋은 교육 방법이 될 수 있다.

• The korean journal of orthodontics
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• v.34 no.4 s.105
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• pp.333-342
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• 2004

The purpose of this study was to evaluate the clinical effectiveness of a plasma arc light and light emitting diode (LED), compared with shear bond strength and the failure pattern of brackets bonded with visible light in direct bonding. Brackets were bonded with Transbond XT to 60 human premolars embedded in the resin blocks according to different light-curing methods. Then, the shear bond strength of each group was measured using a universal testing machine (Instron) and the adhesive failure pattern after debonding was visually examined by light microscope. The results were as follows: 1. The shear bond strength showed no significant difference between the visible light and light emitting diode, but the plasma arc light exhibited a significantly lower shear bond strength compared with the visible light and light emitting diode. 2. In the visible light and light emitting diode, adhesive failure patterns were similar. Bond failure occurred more frequently at the enamel-adhesive interface. 3. The bonding failure of brackets bonded with plasma arc light occurred more frequently at the bracket-adhesive interface. The results of this study suggest that plasma arc light, light emitting diode and visible light are all clinically useful in the direct bonding of orthodontic brackets.

• Parasites, Hosts and Diseases
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• v.31 no.4
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• pp.301-314
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• 1993

An electron microscopic study was performed to observe the ultrastructure of the tegument of U seoulensis. The outer surface of the tegument was covered with a tnlaminated plasma membrane. The electron-dense cytoplasmic layer was $2.5{\;}\mu\textrm{m}$ wide In the anterior portion and contained numerous vacuoles, mitochondriae and granular materials in its matrix. The basement layer was 330 nm wade or so, and Its numerous extensions protruded into the cytoplasmic layer. The sensory organ was composed of a small vesicle of $1.7{\;}{\times}{\;}1.1{\;}\mu\textrm{m}$ in dimensions, which possessed a cilium of $1.2{\;}{\times}{\;}0.19{\;}\mu\textrm{m}$ in size. The pharynx was composed of the epithelial layer of about $0.5{\;}\mu\textrm{m}$ wide, well developed muscle layer and basement layer. The tegument of the oral sucker was composed of a cytoplasmic layer of $0.4-0.5{\;}\mu\textrm{m}$ width, a narrow basement layer, a well developed muscle layer and tegumental cells. Some kinds of secretory granules that seemed to be originated from the cells of the oral sucker were observed In the parenchymal portions of the adjacent cells. The tribocytic organ consisted of numerous microvilli. The microvilli were 5 nm wide and heptalaminated. Two types of secretory granules originated from the gland cells of tribocytic organ were observed In the tegument and parenchyme. The tegumental cells were irregular in shape, and of which nuclei were multifarious.

• Journal of Korea Water Resources Association
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• v.37 no.6
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• pp.509-515
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• 2004

In this study, comprehensive evaluation on the fully coupled SWAT-MODFLOW model is performed. Since combined model can consider the spatially varied daily recharge rate, groundwater modeling would be greatly enhanced. Also, combined model has been able to generate the distribution of groundwater heads with time, surface-subsurface flow modeling would be greatly advanced. River-aquifer interaction is well established in the combined model considering two-way interactions. Consequently, the reliability of groundwater discharge and total runoff of watershed would be greatly enhanced when combined model is used.