• 한국전자파학회논문지
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• 제20권4호
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• pp.381-389
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• 2009

높은 데이터 전송 속도를 갖는 OFDM(Orthogonal Frequency Division Multiplexing) 통신 시스템은 시간 영역에서 높은 PAPR(Peak-to-Average Power Ratio)이 발생되는 중요한 단점이 있다. 이 때문에 송신 신호의 비선형 왜곡을 일으켜 통신 성능을 매우 나쁘게 된다. CI(Carrier Interferometry) - OFDM 시스템은 각각 병렬 데이터를 N개의 모든 부반송파와 서로 직교하는 위상 성분에 실어 전송함으로써 첨두값이 낮추는 효과를 얻는다. 또한, 한 데이터를 N개의 부반송파에 나누어 전송하기 때문에 주파수 다이버시티(FD: Frequency Diversity) 효과를 얻는다. 그러므로 CI-OFDM은 PAPR 저감과 BER 개선에 우수한 성능을 보인다. 그러나 CI-OFDM을 실제로 구현할 때, 송신기에서 모든 데이터마다 각각 다른 위상 성분들과 반송파에 실려 동시에 전송되기 때문에 수신기에서 독립적인 위상 성분들을 차례로 보상할 수 있는가가 매우 중요한 문제점이 된다. 이 논문에서는 Walsh Hadamard 시퀀스를 사용하여 각 병렬 데이터를 구분하고, 동시에 기존 CI-OFDM의 특성을 갖는 개선된 CI-OFDM, 즉 FD-CI-OFDM 시스템을 제안하고 성능을 평가한다 컴퓨터 시뮬레이션을 통하여 그 성능이 기존 OFDM이나 CI-OFDM보다 개선됨을 보인다.

• 한국조경학회지
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• 제37권5호
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• pp.64-77
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• 2009

조경에서는 문화와 철학의 차이에서 오는 다원적인 표현을 추구하고, 조경가는 그 시대의 문화를 반영한 독특한 환경을 제공함으로써 동시대의 세대에게 사회적 목적과 공간적 관계에 대한 감각을 전해준다. 특히 조경가는 설계작품을 통해 그 시대의 예술을 반영하게 되며, 당대의 예술 특성을 현실공간에 투영하게 된다. 역사적으로 조경가들은 모든 형태의 예술행위에서 많은 모티브(motive)를 찾아 왔으며, 특히 회화는 형태 구성에 직접적인 영향을 주어 조형개념의 근간을 이루기도 하였다. 조경에서의 미니멀리즘(Minimalism)은 모더니즘 시대를 통해 상실되었던 미적 대상으로서의 경관과 경관에서의 예술성 향상 그리고 동시대예술의 구현이라는 조경에서의 예술참여적 성격 표방에 상당한 기여를 하였다. 따라서 본 연구는 미술의 미니멀리즘 조형개념이 조경설계의 조형개념에 미친 영향을 설계 작품의 해석적 연구를 통해 미니멀리즘의 수용과 재현 양상을 밝혔으며, 조형개념 특성을 다음과 같이 요약할 수 있다. 첫째, 미니멀리즘 조경의 환원성(reduction)은 원 삼각형 사각형과 같은 단순기하학의 함축된 형태언어를 사용하여 이용자가 즉각적으로 작품의 정체성을 파악하고, 작품의도를 용이하게 파악하도록 하였다. 둘째, 확장성은 선적 요소의 채택으로 개별 요소 상호간을 연결하는 내적 질서와 시각적 방향성을 위한 외연적 활로를 찾고 있다. 셋째, 평면성은 주변 환경과의 차별화를 통하여 무의미한 공간을 정의하고, 경관 연속체로서 지각을 유발하고자 평탄하게 조성된 부지에 부가 요소를 중첩시키거나 시각 이미지를 위해 포장을 패턴화하는 경향을 가진다. 넷째, 연속성은 공간의 중심성을 확보하고 개별공간의 독자성보다 부지의 전체성을 추구하여 조형요소의 반복적 구성과 소재의 반복을 통한 구성 등의 특성을 가진다.

• 자원환경지질
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• 제6권4호
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• pp.201-216
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• 1973

Being believed thus far to be distributed in the wide areas in the vicinity of Seoul, the capital city of Korea, the Yonchon System in its type locality in Yonchon-gun from which the name derived was never previously traced down or correlated to the Precambrian metamorphic complex in Seoul area where the present study was carried out. Due to in accessibility to Yonchon area, the writer also could not trace the system down to the area studied so as to correlate them. The present study endeavored to differentiate general stratigraphy and interprete the structure of the metamorphic complex in the area. In spite of the complexity of structure and rapid changes in lithofacies of the complex, it was succeeded to find out the key bed by which the stratigraphy and structure of the area could be straightened out. The keybeds were the Buchon limestone bed in the western parts of the area; Daisongri quartzite bed cropped out in the southeastern area; Jangrak quartzite bed scattered in the several localities in the northwest, southwest, and eastern parts of the area; and Earn quartzite bed isolated in the eastern part of the area. These keybeds together with the broad regional structure made it possible to differentiated the Precambrian rocks in ascending order into the Kyonggi metamorphic complex, Jangrak group and Chunsung group which are in clinounconformable relation, and the first complex were again separated in ascending order into Buchon, Sihung, and Yangpyong metermorphic groups. Althcugh it has being vaguely called as the Yonchon system thus far, the Kyonggi metamorphic complex have never been studied before. The complex might, however, belong to early to early-middle Precambrian age. The Jangrak and Chunsung group were correlated to the Sangwon system in North Korea by the writer (1972), but it became apparent that the rocks of the groups have different lithology and highly metamorphosd than those of the Sangwon system which has thick sequence of limestone and slightly metamorphosed. Being deposited in the margin of the basin, it is natural that the groups poccess terrestrial sediments rather than limestone, yet no explanation is at hand as to what was the cause of bringing such difference in grade of metamorphism. Thus the writer attempted to correlate the both groups to those of pre-Sangwon and post-Yonchon which might be middle to early-late Precambrian time. Judging from difference in grade of deformation and unconformity between the Kyonggi metamorphic complex, Jangrak group, and Chunsung group, three stages of orogeny were established: the Kyonggi, Jangrak orogenies, and Chunsung disturbance toward younger age. It is rather astonishing to point out that the structure of these Precambrian formations. was not effected by Daebo orogeny of Jurassic age. The post-tectonic block faulting was accompanied by these orogenies, and in consequence NNE and N-S trending faults were originated. These faulting were intermittented and repeated until Daebo orogeny at which granites intruded along these faults. The manifestation of alignment of these faults is indicated by the parallel and straight linear development of valleys and streams in the Kyonggi Massifland.

• 한국가축번식학회지
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• 제20권4호
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• pp.453-458
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• 1997

형질전환 동물의 후손에서 transgene은 멘델의 법칙에 따라 유전된다고 일반적으로 인식되어져 왔다. 따라서 본 연구에서는 transgene이 이러한 인식과 일치하는지를 여러 세대를 통하여 확인하고 후손에서 어떻게 유전되는지를 연구하기 위하여 형질전환 생쥐를 생산하여 본 연구의 모델로 삼았다. 수정된 생쥐의 embryo에 DNA를 microinjection하는 방법으로 MMTV-LTR (long terminal repeat), bovine ($\alpha$s1-casein cDNA, 그리고 SV 40 splicing과 polyadenylation site 등의 sequence를 포함한 3.0Kb의 DNA가 주입되었다. 여기에서 태어난 새끼는 dot blot과 Southern blot에 의하여 transgene의 존재여부가 확인되어 founder line이 만들어졌다. 그들의 자손은 PCR에 의해서 transgene이 유전되는지를 확인하였다. F0의 72마리 새끼중에서 4마리의 Founder가 transgene을 가지고 있었다(5.6%). F0에서 F1으로의 유전(transmission)은 각각 33.3, 7.7, 0, 62.5%이었다. Transgene은 F1에서 F2로 각각 63.6, 5.9, 68.8% 유전되었고, F2에서 F3로 각각 85.7, 0, 88.2% 유전되었다. 따라서 본 연구 모델에 의하면 transgene은 멘델의 법칙을 따르는 경우와 deletion이 되는 경우로 각각 관찰되었다.

• 한국임상약학회지
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• 제15권1호
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• pp.21-26
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• 2005

A bioequivalence study of CKD $Cefaclor^{(R)}$ capsule (Chong Kun Dang Pharm Co., Ltd) to $Ceclor^{(R)}$ capsule (Lilly Korea Co., Ltd.) was conducted according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty four healthy male Korean volunteers received each medicine at the cefaclor dose of 250 mg in a $2{\times}2$ crossover study. There was a one-week washout period between the doses. An improved high-performance liquid chromatorgraphy (HPLC) analytical method with UV detection was used to determine plasma cefaclor concentration in human volunteers for 8 hr after oral drug administration. The area under the plasma concentration-time curve from time zero to 8 hr ($AUC_{0-8hr}$) was calculated by the linear trapezoidal rule. the $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_{0-8hr}\;and\;C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the cross-over design was properly performed. The $90{\%}$ confidence intervals of the $AUC_{0-8hr}$ ratio and the $C_{max}$ ratio for CKD $Cefaclor^{(R)}$ and $Ceclor^{(R)}$ were $0.9400{\leq}{\delta}{\leq}1.0345$ and $0.8858{\leq}{\delta}{\leq}1.1021$, respectively. These values were within the acceptable bioequivalence intervals of 0.80-1.25. Thus, our study demonstrated the of CKD $cefaclor^{(R)}$ capsule was bioequivalent to $Cefaclor^{(R)}$ capsule with respect to its bioavailability.

• 방송공학회논문지
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• 제1권2호
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• pp.176-187
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• 1996

본고는 로보트 팔의 선단에 부착된 카메라에 의하여 촬영된 일련의 스테레오 영상을 이용하여 운동물체의 3차원 자세 (위치와 방향)를 정확히 추정하는 방법을 다룬다. 본고는 이미 발표된 바 있는 연구결과를 확장한 것으로서[1], 2차원 영상의 측정잡음 뿐만아니라[1], 또한 로보트 팔의 죠인트 각도의 랜덤잡음이 함께 존재할 경우 world 좌표계 (또는 로보트 기지좌표계)를 기준으로 한 운동물체의 3차원 자세의 추정에 중점을 둔다. 이를 위하여, 다음 사항에 근거하여 선형 Kalman 필터를 유도한다. (1) 2차원 영상의 측정잡음이 3차원 공간으로 전파되는 것을 분석함으로써, 이에 기인한 물체좌표계의 방향오차를 카메라 좌표계를 기준으로 하여 모델링한다; (2) 죠인트 각도 오차에 의한 로보트 선단좌표계의 방향오차를 (1)의 결과와 결합하여 extended Jacobian matrix를 유도한다; 그리고 (3) 본질적으로 비선형인 물체의 회전운동을 quaternion을 도입함으로써 선형화 한다. 운동 파라메터는 추정된 quaternion으로부터 반복 최소자승 방법을 이용하여 계산된다. 모의실험 결과, 추정오차가 상당히 감소되고, 실제의 운동 파라메터가 참 값으로 정확히 수렴함을 알 수 있다.

• Journal of Pharmaceutical Investigation
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• 제33권3호
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• pp.215-221
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• 2003

A bioequivalence study of $Ambrect^{TM}$ tablets (Dong Wha Pharm. Ind. Co., Ltd.) to $Mucopect^{TM}$ tablets (Boehringer Ingelheim Korea, Ltd.) was conducted according to the guideline of Korea Food and Drug Administration (KFDA). Twenty four healthy male Korea volunteers received each medicine at the ambroxol hydrochloride dose of 30 mg in a $2{\times}2$ crossover study. There was a one-week wash out period between the doses. Plasma concentrations of ambroxol were monitored by a high-performance liquid chromatography for over a period of 24 hours after the administration. $AUC_t$ (the area under the plasma concentration-time curve from time zero to 24 hr) was calulated by the linear trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}\;(time\;to\;reach\;C_{max})$ were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_t\;and\;C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the crossover design was properly performed. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for $Ambrect^{TM}/Mucopect^{TM}$ were 0.89-1.01 and 0.89-1.02, respectively. These values were within the acceptable bioequivalence intervals of 0.80-1.25. Thus, our study demonstrated the bioequivalence of $Ambrect^{TM}\;and\;Mucopect^{TM}$ with respect to the rate and extent of absorption.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2002년도 학술발표대회
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• pp.18-25
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• 2002

The pikromycin biosynthetic system in Streptomyces venezuleae is unique for its ability to produce two groups of antibiotics that include the 12-membered ring macrolides methymycin and neomethymycin, and the 14-membered ring macrolides narbomycin and pikromycin. The metabolic pathway also contains two post polyketide-modification enzymes, a glycosyltransferase and P450 hydroxylase that have unusually broad substrate specificities. In order to explore further the substrate flexibility of these enzymes a series of hybrid polyketide synthases were constructed and their metabolic products characterized. The plasmid-based replacement of the multifunctional protein subunits of the pikromycin PKS in S. venezuelae by the corresponding subunits from heterologous modular PKSs resulted in recombinant strains that produce both 12- and 14-membered ring macrolactones with predicted structural alterations. In all cases, novel macrolactones were produced and further modified by the DesVII glycosyltransferase and PikC hydroxylase leading to biologically active macrolide structures. These results demonstrate that hybrid PKSs in S. venezuelae can produce a multiplicity of new macrolactones that are modified further by the highly flexible DesVII glycosyltransferase and PikC hydroxylase tailoring enzymes. This work demonstrates the unique capacity of the S. venezuelae pikromycin pathway to expand the toolbox of combinatorial biosynthesis and to accelerate the creation of novel biologically active natural products. The polyketide backbone of rifamycin B is assembled through successive condensation and ${\beta}$-carbonyl processing of the extender units by the modular rifamycin PKS. The eighth module, in the RifD protein, contains nonfunctional DH domain and functional KR domain, which specify the reduction of the ${\beta}$-carbonyl group resulting in the C-21 bydroxyl of rifamycin B. A four amino acid substitution and one amino acid deletion were introduced in the putative NADPH binding motif in the proposed KR domain encoded by rifD. This strategy of mutation was based on the amino acid sequences of the corresponding motif of the KR domain of module 3 in the RifA protein, which is believed dysfunctional, so as to introduce a minimum alteration and retain the reading frame intact, yet ensure loss of function. The resulting strain produces linear polyketides, from tetraketide to octaketide, which are also produced by a rifD disrupted mutant as a consequence of premature termination of polyketide assembly. Much of the structural diversity within the polyketide superfamily of natural products is due to the ability of PKSs to vary the reduction level of every other alternate carbon atom in the backbone. Thus, the ability to introduce heterologous reductive segments such as ketoreductase (KR), dehydratase (DH), and enoylreductase (ER) into modules that naturally lack these activities would increase the power of the combinatorial biosynthetic toolbox. The dehydratase domain of module 7 of the rifamycin PKS, which is predicted to be nonfunctional in view of the sequence of the apparent active site, was replaced with its functional homolog from module 7 of rapamycin-producing polyketide synthase. The resulting mutant strain behaved like a rifC disrupted mutant, i.e., it accumulated the heptaketide intermediate and its precursors. This result points out a major difficulty we have encountered with all the Amycolatopsis mediterranei strain containing hybrid polyketide synthases: all the engineered strains prepared so far accumulate a plethora of products derived from the polyketide chain assembly intermediates as major products instead of just analogs of rifamycin B or its ansamycin precursors.

• Journal of Pharmaceutical Investigation
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• 제35권2호
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• pp.117-122
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• 2005

After establishing improved HPLC analytical method of cefaclor in human plasma samples, a bioavailability study of cefaclor capsules was conducted according to the guidelines of Korea Food and Drug Administration (KFDA). The standard calibration curve using an HPLC with UV detector was constructed in a range of $0.0324{\sim}16\;{\mu}g/ml$. The 6% perchloric acid instead of 6% trichloroacetic acid was used to precipitate plasma protein. The HPLC chromatograms were precisely and accurately resolved when spiked with human plasma spiked with cefaclor and cephalexin (internal standard). Twenty healthy male Korean volunteers received two commercial cefaclor capsules, $Neocef^{\circledR}$ capsule (Jinyang Pharm. Co., Ltd) or $Ceclor^{\circledR}$ capsule (Lilly Korea. Co., Ltd.) at the 250 mg cefaclor in a $2{\times}2$ crossover study. There was a one-week washout period between the doses. Plasma concentrations of cefaclor were monitored for 8 hours after oral drug administration. $AUC_t$ the area under the plasma concentration-time curve from time zero to 8 hr (13 points), was calculated by the linear trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_t$ and $C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the cross-over design was properly performed. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for $Neocef^{\circledR}/Ceclor^{\circledR}$ were $0.9049{\leq}{\delta}{\leq}1.226$, respectively. These values were within the acceptable bioequivalence intervals of 0.80-1.25. Thus, our study demonstrated the bioequivalence of $Neocef^{\circledR}/Ceclor^{\circledR}$ with respect to the extent of absorption.

• Journal of Pharmaceutical Investigation
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• 제37권3호
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• pp.197-203
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• 2007

A bioequivalence study of $Dilast^{TM}$ Capsule (Chong Kun Dang Pharma. Co., Ltd.) to $Ketas^{(R)}$ Capsule (Han Dok Pharma. Co., Ltd.) was conducted according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty eight healthy male Korean volunteers received each medicine at the ibudilast dose of 20 mg in a $2{\times}2$ crossover study. There was one week wash-out period between the doses. Plasma concentrations of ibudilast were monitored by a liquid chromatography-tandem mass spectrometry (LC-MS/MS) for over a period of 36 hours after drug administration. $AUC_t$ (the area under the plasma concentration-time curve from time zero to 36 hr) was calculated by the linear trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_t\;and\;C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the crossover design was properly performed. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for $Dilast^{TM}$ $Capsule/Ketas^{(R)}$ Capsule were $log0.93{\sim}log1.06$ and $log0.93{\sim}log1.11$, respectively. These values were within the acceptable bioequivalence intervals of $log0.80{\sim}log1.25$. Thus, our study demonstrated the bioequivalence of $Dilast^{TM}$ Capsule and $Ketas^{(R)}$ Capsule with respect to the rate and extent of absorption.