• 한국지역지리학회지
• /
• 제4권1호
• /
• pp.57-76
• /
• 1998

본 연구는 중국에 대한 지역연구(area studies)의 일환으로, 지금까지 간과되어온 연변조선족 자치주의 주도(州都)인 연길시의 상업 및 서비스업에 대한 우리 기업의 투자입지전략을 모색하기 위하여 지리학적인 관점에서 접근을 시도하였다. 이에 따라 먼저 연길시의 지리적 특성과 상업 및 서비스업의 발전상을 간략히 살펴보고, 다음으로 연길시의 상업 및 서비스업의 지역구조(지역분화)와 지역별 입지특성 및 이용자의 행태적 특성을 분석 고찰하였으며, 마지막으로 이를 기초로 연길시의 상업 및 서비스업에 대한 우리 기업의 투자전략 수립에 유용한 투자정보를 제공하고자 하였다. 본 연구에서는 투자에 적합한 업종으로 백화점, 의류점, 신발점, 화장품점, 가전용품점, 무역기업의 해외사무소, 호텔, 나이트클럽, 한국식 음식점, 노래방, 여행사, 미용소, 비디오감상실, 전자오락실 등을 추천하였으며, 장소적으로는 본 연구에서 밝혀진 연길시의 핵심 상업 서비스업지역 또는 도심지에 투자입지하는 것이 바람직하다고 제안하였다.

• 한국군사과학기술학회지
• /
• 제24권6호
• /
• pp.645-654
• /
• 2021

In this paper, we proposed a protocol to convert 2W telephone analog signals to Ethernet data in a private PSTN 2W tactical voice system. There are several kinds of operational problems in the tactical telephone network where 2W telephone copper lines are installed hundreds of meters away from the PBX in a headquarter site. The reason is that it is difficult to install and maintain the 2W telephone copper cable in severe operational fields and to meet safety and stability operational requirements of the telephone line under lighting and electromagnetic environments. In order to solve these challenging demands, we proposed an efficient method that the 2W analog interface signals between a private PBX system and a 2W telephone is converted to Ethernet messages using the optical Ethernet data communication network already deployed in the tactical weapon system. Thus, it is not necessary to install an additional optic cable for the ethernet telephone line and to maintain the private PSTN 2W telephone network. Also it provides safe and secure telecommunication operation under lightning and electromagnetic environments. This paper presents the conversion protocol from 2W telephone signals over Ethernet interface between PBX systems and 2W telephones, the mutual exchange protocol of ethernet messages between two converters, and the rule to process analog signal interface. Finally, we demonstrate that the proposed technique can provide a feasible solution in the tactical weapon system by analyzing its performance and experimental results such as the bandwidth of 2W telephone ethernet network and the transmission latency of voice signal, and the stability of optic ethernet voice network along with the ethernet data network.

• 대한기계학회논문집B
• /
• 제36권10호
• /
• pp.989-999
• /
• 2012

이젝터는 고압의 유체를 구동관로에서 분출시켜, 그 주변의 저압기체와 운동량 교환을 통하여 저압의 유체를 보다 높은 압력까지 상승시켜 흡인되는 유체를 이송하는 장치이다. 증기-증기 이젝터는 흡입, 혼합 및 탈수에 널리 사용되고 있다. 그리고 이젝터는 기계적인 작동이 없으므로, 고장이 거의 없다. 또한 이젝터는 유체 관련 시스템의 크기에 관계없이 유체와 관련된 다양한 장소에 용이하게 설치할 수 있어, 정비의 필요성이 거의 없고 비용도 합리적이다. 따라서 본 연구는 단순 압축 또는 진공 설비를 위한 펌프 혹은 기계장치 대안으로 사용되는 이젝터 전체에 적용할 수 있는 기초 자료 제공을 목표로 하였다. 이 목표를 위해 실험만으로 획득할 수 없는 자료를 전산유체역학을 적용하여 분석함으로써 이젝터의 유체역학적 특성에 있어 최적의 설계조건을 제시하였다.

• 한국정보통신학회논문지
• /
• 제19권5호
• /
• pp.1131-1136
• /
• 2015

VoIP(Voice over Internet Protocol)와 IP Telephony 기술이 발전함에 따라 기존 회선이 아닌 인터넷 망을 사용하여 전화를 사용하는 IP-PBX(Internet Protocol Private Branch Exchange)의 사용이 증가하고 있다. IP-PBX는 전화회선을 사용하지 않아 전화 업무가 많은 기업들과 기관들의 경영비용을 절감할 수 있으며 일반전화 회선과 유사한 품질을 제공한다. 하지만 IP-PBX를 도입하기 위해선 고가의 하드웨어 장비나 상용 소프트웨어를 구매해야 하는 초기 비용이 필요하다. 본 논문에서는 고가의 하드웨어 장비나 상용 소프트웨어를 구매하지 않고 IP-PBX를 도입할 수 있는 방안을 제안한다. 제안하는 IP-PBX는 Raspberry Pi와 Asterisk를 사용하여 IP-PBX 서버를 설계하고 구현한다. 그리고 구현된 IP-PBX 기반으로 PC와 스마트 폰 간의 음성 통화를 실시하여 논문의 적합성을 검증한다.

• BMB Reports
• /
• 제32권1호
• /
• pp.20-24
• /
• 1999

The first step of the branch pathway in tryptophan biosynthesis is catalyzed by anthranilate synthase, which is subjected to feedback inhibition by the end product of the pathway. The $trpE^{FBR}$ gene from a mutant Escherichia coli strain coding for anthranilate synthase that was insensitive to feedback inhibition by tryptophan has been cloned. To identify the amino acid changes involved in the feedback regulation of anthranilate synthase, the nucleotide sequence of the mutant $trpE^{FBR}$ gene was determined. Sequence analysis of the $trpE^{FBR}$ gene revealed that four bases were changed in the structural gene while alteration was not found in the 5' control region. Among these base changes, only two base substitutions caused the alterations in amino acid sequences. From the results of restriction fragment exchange mapping, the 61st nucleotide, C to A substitution, that changed $Pro^{21}{\rightarrow}Ser$ was identified as the cause of the desensitization to feedback inhibition by tryptophan. Additional feedback-resistant enzymes of the E. coli anthranilate synthases were constructed by site-directed mutagenesis to examine the effect of the $Ser^{40}\;{\rightarrow}\;Arg^{40}$ change found in the $trpE^{FBR}$ gene of Brevibacterium lactofermentum. From the feedback inhibition analysis, the $Pro^{21}{\rightarrow}Ser$ and $Ser^{40}{\rightarrow}Arg$ mutants maintained about 50% and 90% of their maximal activities, respectively, even at the extreme concentration of 10 mM tryptophan. From these results, we suggest that the $Pro^{21}$ and $Ser^{40}$ residues are involved in the tryptophan binding in the E. coli enzyme.

• 한국정보통신학회논문지
• /
• 제18권6호
• /
• pp.1323-1329
• /
• 2014

본 논문은 인접 심볼 간의 간섭이 발생하지 않는 최대 데이터 전송률인 Nyquist rate 보다 빠르게 데이터를 전송하여 전송량을 증가시키는 FTN(Faster than Nyquist) 기법을 이용하여 효율적인 복호 방식을 분석한다. FTN 신호 전송시 발생하는 ISI(Inter-Symbol Interference) 를 최소화하기 위해 간섭량을 비터비 등화기의 가지 정보로 활용하여 비터비 등화기 모델을 제안한다. 본 논문에서는 FTN 신호를 복호하기 위해 BCJR 기법을 이용한 비터비 등화기와 LDPC 복호기간의 반복으로 이루어진 터보 등화 기법을 이용하여 복호한다. BCJR 복호시 트렐리스 구조를 본 논문에서는 유클리디언 거리를 최대로 함으로써 기존의 방식보다 성능이 향상됨을 알 수 있으며, 이에 따른 FTN 신호의 전송량 증가별 성능을 비교한다.

• 대한화학회지
• /
• 제39권11호
• /
• pp.842-847
• /
• 1995

유리질 탄소전극을 사용하여 조사한 몇가지 N'-aryl-N-alkyl-N-nitrosourea 유도체들의 전기화학적 환원반응은 확산지배적이고 비가역적인 반응이었다. 이들 유도체들의 환원 반응시의 교환속도 상수 $k_0$값은 $1.48{\times}10^{-6}{\sim}5.32{\times}10^{-7}\;cm/sec.$의 값을 나타내었었다. Aryl기 및 alkyl기의 치환기에 따른 교환속도상수는 $k_0$ N'-aryl-N-alkyl-N-nitrosourea 에서 aryl기가 phenyl일 경우, 다른 치환기보다 $k_0$값이 1.3-2.8배였다. N'-aryl-N-alkyl-N-nitrosourea 와 N'-aryl-N-(2-chloroethyl)-N-nitrosourea의 두 화합물에서 aryl기의 치환기가 같을 경우는 비슷한 값을 나타내었다. N'-aryl-N-methyl-N-nitrosourea 유도체는 pH값이 높아짐에 따라 $E_p$값이 음전위쪽으로 이동하며 각 환원 반응에 참여한 $H^+$의 수는 4-5개였다. 이경우 aryl기의 치환기 효과는 환원전위에 크게 영향을 미치지 않는 것으로 나타났다.

• 한국패류학회지
• /
• 제22권1호
• /
• pp.63-86
• /
• 2006

A list of species of bivalve mollusks, their local distributions and relative abundance in Yeongil Bay were analysed. Species richness ranging from 1 to 37 species was low (less than 10) in some stations at the entrance and in the central part of the bay. Fifteen species (Acila insignis, Nucula tenuis, Yoldia notabilis, Mytilus galloprovincialis, Arca boucardi, Axinopsida subquadrata, Felaniella usta, Mactra chinensis, Raeta pulchella, Nitidotellina hokkaidoensis, Theora fragilis, Alvenius ojianus, Callithaca adamsi, Ruditapes philippinarum and Laternula anatina) were most frequently encountered, and seven of them were most abundant numerically (per sample): Th. fragilis in the inner bay, A. insignis, N. tenuis, and A. ojianus in the outer bay, and C. adamsi, A. subquadrata, R. puichella in both parts. Local distributions of common species were described and presented in plotted data, and three distribution patterns were recognized. Biogeographical analysis shows that a majority of species (55%) belongs to the subtropical group, tropical-subtropical species (16%) play a relatively significant role, and the percentage of boreal (temperate) and boreal-arctic species is 18% which characterizes the whole fauna as subtropical. Zonal-biogeographical composition and number of species in families in Yeongil Bay are compared with those of some Japanese (Wakasa and Mutsu) and Russian (Peter the Great, Possjet and Amursky) bays of the East Sea. The absence of a number of typical warm-water embaymental mollusks in Yeongil Bay found in the north further East Sea and Japan, and the similar zonal-biogeographical structure of the inner and outer bay faunas are explained by active water exchange due to the openness of the bay, relatively low summer temperatures, and presence of upwelled cold waters.

• 대한한의학회지
• /
• 제42권2호
• /
• pp.72-81
• /
• 2021

Objectives: We compared research characteristics of western medicine, Chinese medicine and Korean medicine on causes, mechanisms, types, treatments and prevention of psoriasis. Methods: For western medicine, "Psoriasis" was used as keyword on Pubmed, for Chinese medicine, "銀屑病" and "中医" on CNKI (China National Knowledge Infrastructure" and for Korean medicine, "건선" on OASIS. Keyword searches were done for papers and books published after 2010. For Chinese medicine, there were more in-depth searches done for "從血論 (血熱, 血瘀, 血燥)" and "陽虛症". Results: Western medicine puts an emphasis on the foci, and approaches it from molecular and genetic levels based on molecular biology; while it views psoriasis as a disease with multiple possible causes, it ultimately sees it as an inflammation that is immunity-mediated. Western medicine seeks to suppress cytokine in order to prevent and eliminate inflammation at each stage of treatment While they are effective short-term, psoriasis recurs shortly after. Chinese and Korean medicines categorize psoriasis as an internal comprehensive systemic diseases that encompasses the patient's physical and mental characteristics, and defines it as a disease that has many causes and mechanisms such as "血熱, 血瘀, 血燥" and "陽虛". They use herbal medicine, acupuncture, and lifestyle interventions to improve the overall health of the patient in addition to treating psoriasis. Treatments are effective, but it takes relatively longer to see results, and can recur. Conclusion: In order for more progress to happen on psoriasis treatment, each branch of medicine must exchange knowledge and information more frequently.

• 한국실내디자인학회논문집
• /
• 제20권5호
• /
• pp.236-244
• /
• 2011

As the digital information infrastructure is established for the public library system in the contemporary age, expectations and demands surrounding the public library system are growing rapidly as the place of exchange and enjoyment of information and culture, and as the place of life-long learning. In addition, a new kind of information & culture services are needed to meet the demands of contemporary men and women, who are exploring information as the information environment undergoes rapid changes - from increase in the volume of digital publications, to increase in the usefulness of online information resources, to strides made in the media industry. The public library will continue to play its role and function by providing to all users all available information, whether it's available online or offline, whether it's in a physical format or in a digital format. As such, design and management of a space appropriate as a new information environment are needed. It is deemed that an information infrastructure for Daegu that can improve the quality of life in the region and can increase user accessibility to information in this information age is needed, as well as reorganization of the pertinent environment. Therefore more public libraries have to be built in Daegu as a necessity, and it is urgently needed that the information services be expanded through an organic linkage between local libraries such as between the central library and the branch libraries. This paper aims to provide basic data for building of public libraries in Daegu. To establish an information infrastructure for Daegu, a direction is given for the establishment of a local network of public libraries and ways for improvement are explored. This paper is significant in that, first, it helps in the planning of a local network of public libraries, which plays a crucial role in improving accessibility to information as well as the level of their use; and second, it helps in setting up guidelines for spatial configuration of the user space. As for the method, quantitative review of the information environment is to be done by analyzing the present situation of the public library network in Daegu from the perspectives of region, facility, and space, in order to present a method of user-centered spatial configuration that meets the changes in social roles and forms of information in the contemporary society.