• 디지털콘텐츠학회 논문지
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• 제18권7호
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• pp.1281-1291
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• 2017

본 연구는 e-커머스의 진화 과정을 정리하면서 초기의 사업모델부터 최근 페이스북을 중심으로 나타나고 있는 새로운 형태의 커머스인 스마트 커머스의 출현까지 지난 20여 년 동안 국내 전자상거래 산업이 어떻게 진화되어 왔는지를 단계별로 고찰하였다. 연구자들은 단계별 진화 과정을 나선형 진화 이론을 적용, 비즈니스 모델의 진화, 플랫폼의 진화, 고객 서비스 가치의 진화, 분석과 평가 등 네 가지 진화 요인을 중심으로 설명하였고, 또 단계별 진화 과정에서 축적된 기술과 경험의 축을 중심으로 사업자의 관점과 사용자의 관점에서 탐색과 활용 이론을 적용, 혁신적인 기술과 고객의 피드백을 분석, 혁신적인 비즈니스 모델을 제시하였다. 연구자들은 산업의 진화 연구를 통해 미래를 예측할 수 있다는 측면에서 본 연구가 e-커머스 산업과 정책에 대한 이론적, 실무적 공헌 점이 있을 것으로 기대한다.

• Journal of Gastric Cancer
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• 제1권3호
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• pp.129-135
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• 2001

Purpose: Dysplasia or flat adenoma of the stomach is regarded as a precancerous lesion. However, the frequency and the evolutionary process of malignant transformation of gastric dysplasia are still debated. In order to see whether the lesion was a monoclonal or a polyclonal proliferation, clonality was assayed by X-linked HUMARA polymorphism. Materials and Methods: DNA was extracted from the paraffin-embedded tissue of 16 consecutive cases of endoscopic biopsy, eight of which supplied both dysplastic and nondysplastic tissue for comparison. HUMARA was amplified by PCR with or without pretreatment with methylationsensitive restriction enzyme, HpaII. The amplification products were electrophoresed on polyacrylamide gel and silver-stained. Results: Among the 16 cases, 13 cases were informative and 3 cases noninformative. Of the 13 cases, one case showed skewed lyonization, rendering 12 cases to be analyzed further. A monoclonal band pattern was noted in 2 cases, and a polyclonal band pattern in 10 cases. A review of the histopathologies of the monoclonal and the polyclonal cases did not reveal features discriminating the two groups. Conclusion: These results suggest that gastric dysplasia is a disease entity heterogeneous in the genetic level, and many cases may be non-neoplastic.

• BMB Reports
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• 제53권10호
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• pp.521-526
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• 2020

Endogenous retroviruses (ERVs) are retrotransposons present in various metazoan genomes and have been implicated in metazoan evolution as well as in nematodes and humans. The long terminal repeat (LTR) retrotransposons contain several regulatory sequences including promoters and enhancers that regulate endogenous gene expression and thereby control organismal development and response to environmental change. ERVs including the LTR retrotransposons constitute 8% of the human genome and less than 0.6% of the Caenorhabditis elegans (C. elegans) genome, a nematode genetic model system. To investigate the evolutionarily conserved mechanism behind the transcriptional activity of retrotransposons, we generated a transgenic worm model driving green fluorescent protein (GFP) expression using Human endogenous retroviruses (HERV)-K LTR as a promoter. The promoter activity of HERV-K LTR was robust and fluorescence was observed in various tissues throughout the developmental process. Interestingly, persistent GFP expression was specifically detected in the adult vulva muscle. Using deletion constructs, we found that the region from positions 675 to 868 containing the TATA box was necessary for promoter activity driving gene expression in the vulva. Interestingly, we found that the promoter activity of the LTR was dependent on che-1 transcription factor, a sensory neuron driver, and lin-15b, a negative regulator of RNAi and germline gene expression. These results suggest evolutionary conservation of the LTR retrotransposon activity in transcriptional regulation as well as the possibility of che-1 function in non-neuronal tissues.

• Parasites, Hosts and Diseases
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• 제51권5호
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• pp.525-530
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• 2013

The ascarids, Toxocara canis and Toxascaris leonina, are probably the most common gastrointestinal helminths encountered in dogs. In order to understand biological differences of 2 ascarids, we analyzed gene expression profiles of female adults of T. canis and T. leonina using CLC Genomics Workbench, and the results were compared with those of free-living nematode Caenorhabditis elegans. A total of 2,880 and 7,949 ESTs were collected from T. leonina and T. canis, respectively. The length of ESTs ranged from 106 to 4,637 bp with an average insert size of 820 bp. Overall, our results showed that most functional gene annotations of 2 ascarids were quite similar to each other in 3 major categories, i.e., cellular component, biological process, and molecular function. Although some different transcript expression categories were found, the distance was short and it was not enough to explain their different lifestyles. However, we found distinguished transcript differences between ascarid parasites and free-living nematodes. Understanding evolutionary genetic changes might be helpful for studies of the lifestyle and evolution of parasites.

• 한국가금학회지
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• 제28권2호
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• pp.143-153
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• 2001

Using bioinformatic tools for searching the massive genome databases, it is possible to Identify new genes in few minutes for initial discoveries based on evolutionary conservation, domain homology, and tissue expression patterns, followed by further verification and characterization using the bench-top works. The development of high-density two-dimensional arrays has allowed the analysis of the expression of thousands of genes simultaneously in the humans, mice, rats, yeast, and bacteria to elucidate the genes and pathways involved in physiological processes. In addition, rapid and automated protein identification is being achieved by searching protein and nucleotide sequence databases directly with data generated from mass spectrometry. Recently, analysis at the bio-chemical level such as biochemical screening and metabolic profiling (Biochemical genomics) has been introduced as an additional approach for categorical assignment of gene function. To make advantage of recent achievements in computational approaches for facilitated gene discoveries in the avian model, chicken expression sequence tags (ESTs) have been reported and deposited in the international databases. By searching EST databases, a chicken heparanase gene was identified and functionally confirmed by subsequent experiments. Using combination of sub-tractive hybridization assay and Genbank database searches, a chicken heme -binding protein family (cSOUL/HBP) was isolated in the retina and pineal gland of domestic chicken and verified by Northern blot analysis. Microarrays have identified several host genes whose expression levels are elevated following infection of chicken embryo fibroblasts (CEF) with Marek's disease virus (MDV). The ongoing process of chicken genome projects and new discoveries and breakthroughs in genomics and proteomics will no doubt reveal new and exciting information and advances in the avian research.

• 대한기계학회논문집B
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• 제34권7호
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• pp.679-688
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• 2010

본 연구에서는 기존의 역열전달 문제(inverse heat transfer problem)와 같이 역해석(inverse analysis)을 통해 미지의 파라미터를 추정(estimation)하는 개념을 복잡한 연소문제에 도입하였다. 기존의 연구에서는 역해석 기법을 연소문제 자체에 보다는 대부분 연소현상을 동반한 복사열전달과 같은 역열전달 문제에 국한해서 적용하고 있기 때문에, 열전달 문제에 한정되어 사용되고 있는 기존의 역해석을 새로운 공학문제에 확장하여 적용함과 동시에 효율적인 연소기 설계 및 최적화 개념을 제시하는데 본 연구의 의의가 있다고 할 수 있다. 이를 위해 실제적으로 많이 사용하고 있는 축대칭 원통형 연소기 내부로 주입되는 메탄($CH_4$)과 산소($O_2$) 성분의 초기 질량분율 값을 연소기 입구 근방에서 측정한 개스의 온도 데이터를 이용하여 역추정하였다. 이때, 복잡한 확산지배 연소 현상을 효율적으로 역해석하기 위해 최적화 방법 중의 하나인 반발 입자 군집 최적화 방법을 역해석 기법으로 적용하였다.

• 전자공학회논문지C
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• 제36C권11호
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• pp.75-83
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• 1999

주어진 응용에 적합한 MLP 분류기의 위상 구조를 효율적으로 학습하기 위하여 종족 유전 알고리즘 (SGA)과 파라미터 프리 유전 알고리즘(PfGA)을 결합한 파라미터 프리 종족 유전 알고리즘(PfSGA)을 제안한다. SGA는 전체 탐색 공간을 은닉층 뉴런의 수에 따라 여러 개의 영역(종족)으로 분할한 후, 학습 과정 중 기준에 미달되는 종족에 대해서는 학습을 중단시킴으로써 불필요한 탐색을 줄이는 학습법이다. 그러나 SGA는 돌연변이나 교배 확률 등 학습 파라미터 설정에 따라 분류기의 성능이 달라진다. 따라서 이 논문에서는 SGA와 PfGA를 결합하여 파라미터 설정에 무관하도록 하였다. 벤치마크 데이터와 수화 단어에 대하여 실험한 결과 PfSGA는 기존의 SGA에 비해 학습 시간을 단축시킬 수 있으며, 파라미터의 설정에 영향을 받지 않았다. 또한 기존의 방법에 비해 오인식율과 위상 구조 등에 있어서 효율적임을 확인하였다.

• 국제초고층학회논문집
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• 제5권4호
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• pp.251-262
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• 2016

Tall Buildings have been one of the most prominent symbols of economic growth for nearly a century. Yet, in the aftermath of the tragedies of September 11, "signature" Tall buildings have become the focus of much debate. The structural systems today are undergoing a major evolution to address the ability of providing flexibility in the design and use of the building together with sustainability (Green) and cost-effective system. This paper describes a new invented structural system, evolutionary structural analysis and design of Tall buildings, which involves the entire analysis process, including conceptual and design stages and comparison with the existing Tall building. This study presents an new innovative structural system, Beehive (Hexagrid), for Tall buildings. The final results are achieved by modeling an 80 story Tall building with the optimized angle and topology of hexagon members by using a computer analysis, ETABS finite element analysis. The objective function of this system is to use one structural system in order to both maximize Eigen frequency for resisting dynamic responses and minimize mean compliance for static responses. Finite element analysis is carried out by using standardized materials. Optimal Hexagrid topologies with the highest stiffness are finally determined to resist both static and dynamic behaviors. Holistic design integration approaches between structures and facades to save energy for environmental control are studied. Innovative design ideas to control structural motion as well as to utilize that motion to harness energy are discussed. Considering abundant emergence of tall buildings all over the world in recent years, the importance of the studies presented in this paper cannot be overemphasized for constructing more sustainable built environments.

• Advances in concrete construction
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• 제8권4호
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• pp.269-276
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• 2019

The cracking and spalling caused by fracture of concrete lining have adverse impacts on serviceability and durability of the tunnel, and the subsequent maintenance work for damaged structure needs to be specific to the damaging causes. In this paper, a particular case study of an operational tunnel structure is presented for the serious cracking and spalling behaviours of concrete lining, focusing on the multi-factors inducing lining failure. An integrated field investigation is implemented to characterize the spatial distribution of damages and detailed site situations. According to results of nondestructive inspection, insufficient lining thickness and cavity behind lining are the coupled-inducement of lining failure bahaviors. To further understanding of the lining structure performance influenced by these multiple construction deficiencies, a reliable numerical simulation based on extended finite element method (XFEM) is performed by using the finite element software. The numerical model with 112 m longitudinal calculation, 100 m vertical calculation and 43 m vertical depth, and the concrete lining with 1450 solid elements are set enrichment shape function for the aim of simulating cracking behavior. The numerical simulation responses are essentially in accordance with the actual lining damaging forms, especially including a complete evolutionary process of lining spalling. This work demonstrates that the serious lining damaging behaviors are directly caused by a combination of insufficient thickness lining and cavity around the surrounding rocks. Ultimately, specific maintenance work is design based on the construction deficiencies, and that is confirmed as an efficient, time-saving and safe maintenance method in the operational railway tunnel.

• 한국멀티미디어학회논문지
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• 제9권10호
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• pp.1344-1353
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• 2006

디지털과 디자인의 접목이라는 사회적 가치에 부합하는 제품의 측면에서, 최근 사용자층의 차장과 디자인 혁신을 꾀하면서 다양한 방식으로 디지털기술과의 융화를 시도하고 있는 브릭 완구에 대한 중요성이 나날이 높아지고 있다. 브릭에 대한 기존의 연구는 아날로그 측면의 놀이와 교육 도구로서의 역할에 치중함으로써 실제로 그 가치 이외의 무한한 가능성과 멀티미디어 측면에서의 확장성에 관한 연구가 부족한 것이 사실이다. 본 연구는 점차 사용성이 확대되고 있는 브릭 시스템 완구가 어떤 방식으로 진화되었는가에 대한 문제 제기에서 출발하여 브릭에 관한 기본적 이론 연구와 구체적 사례 분석을 통해 변화된 현황을 살펴보는 것으로 이루어져 있다. 이를 토대로 최종적으로는 확장된 형식의 대표적 브릭 시스템 사례를 적용한 디자인 프로세스를 수행함으로써 디지털 브릭 시스템의 가능성을 보다 체계적으로 보여 줄 수 있을 것으로 기대한다.