• Information and Communications Magazine
• /
• v.14 no.12
• /
• pp.77-85
• /
• 1997

지금까지 access network에서의 xDSL의 위치를 살펴보고 DSL, HDSL, ADSL 및 VDSL을 중심으로 기술 및 최근의 표준화동향을 살펴보았다. ITU의 조사에 따르면 97년 기준으로 전세계 약 8억가구에 copper access line이 연결되어 있고 그중의 70%이상이 가정에 연결되어 있는데 증가추세도 북미의 경우 년3.5%, 서유럽과 태평양연안의 경우 년4.5%의 성장율을 보이고 있어 2000년경에는 10억가구에 다다를 전망이다. 미국은 97년기준 약 1억가구에 1억6000만 copper access line이 연결되어 있는데 Yankee Group이 조사한 바에 따르면 2000년을 기준으로 3백만가구에 ADSL/RADSL/SDSL이 연결되고 관련 revenue는 10억달러에 이를것으로 추산하고 있다. 전세계 xDSL 시장규모를 미국의 5배정도로 보면 2000년경에는 전세계 twist pair의 2%정도에 xDSL이 연결되어 ADSL/RADSL/SDSL 관련 세계시장규모가 50억달러에 이르고 시장성장률은 30%에 이를 것으로 보고 있다. 현재 이러한 xDSL의 표준화작업은 3장에서 언급한 바와 같이 ANSI T1, ETSI에서 주로 주도되고 있으나 ITU-T, IEEE, ADSL Forum, ATM Forum, DAVIC 등 다른 group과 활발한 liasion meeting 을 통해서도 협력안을 마련하려 노력하고 있다. 예를 들어 DAVIC은 long range(1.5Km이상) PMD규격으로 ADSL을, mid range($300m\sim1.5km$) PMD규격으로 VDSL을, short range(300m이하) PMD규격으로 CAP방식의 FTTC를 각각구정하여 xDSL을 수용하고 있다. Microsoft의 CEO인 Bill Gates가 'Bandwidth bottleneck. No question. that's the biggest obstacle.'이라고 천명한 바와 같이 정보사회로의 진전에 있어 bandwidth는 시급히 해결되어야 할 문제이다. 정보사회의 꿈을 실현하고자 1993년부터 시작된 In-formation Infrastructure의 구축노력이 그동안 다양하게 시도되어왔으나 숱한 우여곡절과 실패를 겪은 telco등의 서비스업자들이 이제는 너무 큰 꿈을 쫓기보다는 internet이라는 현실적인 시장에서 xDSL과 cablemodem을 바탕으로 차근차근 새로 시작하고 있다고 생각된다. 그동안 ADSL, Forum을 중심으로한 일부 technology evangelist들은 전세계 8억가구에 깔려있는 copper twist pair를 경제적인 'the last mile solution'으로 활용할 것을 줄기차게 주장해왔다. 그동안 xDSL은 VDSL이라는 차세대 대안을 제시하여 interim solution이라는 울타리를 벗어나는데 성공하였을 뿐만 아니라 IDSL, SDSL, RADSL등의 새로운 고객지향적 xDSL을 개발하여 선택의 폭을 넓혀주었다. xDSL vendor들간의 치열한 경쟁속에서 값싼 xDSL 시스템들이 속속 등장하고 있으며, DSLAM[8]과 같은 switch solution도 제시되어 기존의 copper twist pair를 이용해 값싸게 다양한서비스를 제공해 줄 수 있는 기틀을 마련한 것이 오늘날의 xDSL의 성공요인이라고 생각된다. 일찌기 Bell Atlantic의 CEO Ray Smith가 'Yes. ADSL is an interim solution that will be with us for forty years.'라고 간파한대로 xDSL은 fiber가 좀 더 값싼 해결책이 될 때까지 당분간 access network에서 확고한 자리를 구축할 것으로 보인다. 최근들어 우리나라의 초고속정보통신망도 ADSL 과 VDSL을 바탕으로 FTTH으로 진화하는 전략을 수립한것은 우리의 현실과 세계적인 추세를 반영한 일이라 여겨진다.

• 전기의세계
• /
• v.29 no.3
• /
• pp.170-176
• /
• 1980

이 논문은 제어신호가 이상적인 포화특성을 갖은 제작조건하의 시불변, 선형 제어계의 시최적화 제어기구의 설계이론을 비교 연구하는데 목적을 두었다. 어떤 초기상태에 있는 계를 특정된 최종상태로, 최단시간내에 이행시켜 가는데 요구되는 제어기구의 설계문제는 여러해 동안 흥미있는 연구과제로 학계에 등장되었고 이러한 문제를 처리하는데에는 여러가지의 설계방법이 제안되어 왔다. 이 논문에서는 이러한 최적화 제어기구의 설계 이론중, 상태천이법에 의한 방법, 최대원리의 적용에 의한 방법 및 동적 프로그래밍기법에 의한 방법들을 서로 비교하여 2차계의 시최적화 설계사례에 이들을 적용시킴으로써 그 설계법상의 문제점을 비교 검토하여 보려는데 목적을 두었다. 설계사례 2차계는 시불변, 선형인 것으로 가정하였으며, 초기상태벡터 및 최종상태벡터는 모두 특정된 값으로 지정되고 제어신호는 이상적인 포화특성으로 제약받으며 스윗칭 시간이 유한크기가 아닌 정규형인 경우에 한정시켜 다루었다. 어느 설계이론을 적용시키나 시최적화를 위한 제어측은 단속제어방식으로 결과되었으나, 시최적화 문제의 특수성때문에 최대원리 및 동적 프로그래밍기법의 적용사례에서는 자연경계조건 및 Transversality 조건 등이 스윗칭시간 또는 최종시간을 직접 결정하여 주는 관건은 되지 못하였으며 계통의 상태방정식 또는 보조상태방정식을 구속제약된 양단상태량을 만족하도록 최적에어측을 적용하여 풀므로써 스윗칭시간과 최종시간이 얻어진다. 따라서 어느 한가지 방법의 적용만으로는 수학적인 처리상의 애로는 피할길이 없었으며 Hamiltonian함수의 변화성질을 보조적으로 활용하여 가면 이러한 번거로움이 덜하여 지긴하나, 다루는 계통의 차수가 높을 수록 이러한 수치해를 얻기위한 번거로움은 여간한 험로가 아닌 것으로 생각된다. 결론적으로 이러한 시최적화문제의 설계에는 몇가지의 혼용적용이 바람직하다고 결론된다. 이의 개발에 박차를 가하지 않을 수 없는 것이다.고, 우선 여기서는 당면문제로서 대처하지 않으면 안될 자동주파수제어문제및 계통의 경제운용문제만에 한정하여, 이것을 우리나라의 현상과 관련시켜 개설하고, 이들의 자동화에 관한 기본적인 문제를 간단히 적어 보겠다. 가능하다. 제작완료된 ASIC은 기능시험을 완료했으며 실제 line-of-sight(LOS) 시스템 구현에 적용중이다. 시대를 살아 갈 회원들이다. '컨텐츠의 시대'가 개막되는 것이며, 신세기통신과 SK텔레콤은 선의의 경쟁 과 협력을 통해 이동인터넷 서비스의 컨텐츠를 개발해 나가게 될 것이다. 3배가 높았다. 효소 활성에 필수적인 물의 양에 따른 DIAION WA30의 라세미화 효율에 관하여 실험한 결과, 물의 양이 증가할수록 그 효율은 감소하였다. DIAION WA30을 라세미화 촉매로 사용하여 아이소옥탄 내에서 라세믹 나프록센 2,2,2-트리플로로에틸 씨오에스터의 효소적 DKR 반응을 수행해 보았다. 그 결과 DIAION WA30을 사용하지 않은 경우에 비해 반응 전환율과 생성물의 광학 순도는 급격히 향상되었다. 전통적 광학분할 반응의 최대 50%라는 전환율의 제한이 본 연구에서 찾은 DIAION WA30을 첨가함으로써 성공적으로 극복되었다. 또한 고체 염기촉매인 DIAION WA30의 사용은 라세미화 촉매의 회수 및 재사용이 가능하게 해준다.해준다.다. TN5 세포주를 0.2 L 규모 (1 L spinner flask)oJl에서 세포간의 응집현상 없이 부유배양에 적응,배양시킨 후 세포성장 시기에 따른 발현을 조사한 결과 1 MOI의 감염조건 하에서는 $0.6\times10^6$cell/mL의 early exponential시기의 세포밀도에서 72시간 배양하였을 대 최대 발현양을 나타내었다. 나타내었다. $\beta$4 integrin의

• Journal of Service Research and Studies
• /
• v.10 no.1
• /
• pp.17-31
• /
• 2020

Open banking, the global trend of the financial industry, is the driving force behind various innovations in the financial market in the future. The right policy direction and detailed tasks are important for triggering the differentiation and reunion of the financial industry. The purpose of this study is to investigate and analyze the background of open banking, domestic and international trends, and Korea's open banking policy. The policy directions and tasks for successful settlement and activation of open banking system are carefully suggested. Open banking is a policy to allow third party provider(TPP) access to bank accounts and open payment functions under the explicit consent of the customer. The opening of the open banking era is expected to begin competition and cooperation between banks and fintech companies in earnest, thus enhancing the competitiveness of the financial industry and contributing to the utility of financial consumers. To this end, policymakers should make every effort to advance open-ended financial settlement infrastructure, open banking legal grounds, and minimize side effects such as customer data leakage and poor financial system stability. Banks and fintech companies will need to focus on scattered customer financial information on a single platform and develop it into a convergence and discrimination of true financial services.

• Korean Security Journal
• /
• no.15
• /
• pp.173-198
• /
• 2008

As we took a look at above, this researcher suggest following device to extend Korea's private security industry's area. First, it is necessary to extend private investigation law's area grafting private security together. Second, it is necessary it is necessary to think of private security's role related key figure law, corresponding terror law, Presidential Security Service Guard law. Third, as a draft of a proposed law related prevention flowing out of industry techniques among industry security related law, passed, it is necessary private security's diversity, subdivision, composition through an enterprise security, and private security industry area's grafting together. Fourth, a research about private security company's investment and professional area's bringing up as well as business's extension device should be groped for the security consulting though total system management service. Fifth, there are no big difference education course and purpose, duty about a security police man law and security law's unification, so it is necessary to drive forward actively unification through government organization's cooperation. Sixth, a paradigm shift should be occured about private security service among policeman, citizen, and private security guards. Seventh, it is considered the role of security association is important. Lastly about a matter communication between the National Police Agency, and Security Association, not only look at from an authority's angle, collecting information, corresponding ability but now it is considered to grope each other cooperation device together among organizations not only the National Police Agency but also, National Organization, National Intelligence Service, the prosecution, Presidential Security Service Guard, Army etc.

• The KIPS Transactions:PartB
• /
• v.9B no.4
• /
• pp.389-390
• /
• 2002

It is important that acquire information about if customer has some habit in electronic commerce application of internet base that led in recommendation service for customer in dynamic web contents supply. Collaborative filtering that has been used as a standard approach to Web personalization can not get rapidly user's preference change due to static user profiles and has shortcomings such as reliance on user ratings, lack of scalability, and poor performance in the high-dimensional data. In order to overcome this drawbacks, Web usage mining has been prevalent. Web usage mining is a technique that discovers patterns from We usage data logged to server. Specially. a technique that discovers Web usage patterns and clusters patterns is used. However, the discovery of patterns using Afriori algorithm creates many useless patterns. In this paper, the enhanced method for the construction of dynamic user profiles using validated Web usage patterns is proposed. First, to discover patterns Apriori is used and in order to create clusters for user profiles, ARHP algorithm is chosen. Before creating clusters using discovered patterns, validation that removes useless patterns by Dempster-Shafer theory is performed. And user profiles are created dynamically based on current user sessions for Web personalization.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39B no.5
• /
• pp.309-316
• /
• 2014

It is easy to reverse engineer an Android app package file(APK) and get its decompiled source code. Therefore, attackers obtains economic benefits by illegally using the decompiled source code, or modifies an app by inserting malware. To address these problems in Android, we propose an APK overwrite scheme that protects apps against illegal modification of themselves by using a new anti-reverse engineering technique. In this paper, the targets are the apps which have been written by any programmer. For a target app (original app), server system (1) makes a copy of a target app, (2) encrypts the target app, (3) creates a stub app by replacing the DEX (Dalvik Executable) of the copied version with our stub DEX, and then (4) distributes the stub app as well as the encrypted target app to users of smartphones. The users downloads both the encrypted target app and the corresponding stub app. Whenever the stub app is executed on smartphones, the stub app and our launcher app decrypt the encrypted target app, overwrite the stub app with the decrypted target one, and executes the decrypted one. Every time the target app ends its execution, the decrypted app is deleted. To verify the feasibility of the proposed scheme, experimentation with several popular apps are carried out. The results of the experiment demonstrate that our scheme is effective for preventing reverse engineering and tampering of Android apps.

• Korean journal of communication and information
• /
• v.47
• /
• pp.23-49
• /
• 2009

The purpose of the study is to suggest contents, and a range of a Nonnative Theory and a practice for overcoming a crisis of the Mass media. In order to achieve the purpose of the study, a limitation and implication of Social Responsibility Theory was looked into by investigating a Hutchins Report. Hutchins Report suggested the related points at moral duty and legal obligation in implementing mass media's Social Responsibility and Accountability, with relations in publics and community. However, within a view point of a lack of Accountability, Social Responsibility Theory limited responsibility to the realm of 'function', 'self-regulation' and 'self-ethics', In order to promote mass media's quality and serve to rehabilitate its reliability under the pluralistic media system, the contents of Social Responsibility and its scope should be suggested. Media Accountability is a starting point to draw out the contents and scope of Social Responsibility and also a valid democratic plan for mass media to 'social self-regulation' through the mutual communication with civil society. For future Social Responsibility and Media Accountability that is suitable for various mass media, and contents and a range should be defined.

• Journal of Digital Convergence
• /
• v.18 no.7
• /
• pp.357-368
• /
• 2020

This study identifies the aspects and characteristics of 'Digital Sexual Crimes' that changed rapidly in recent years. It has identified the so-called "Telegram sexual harassment and exploitation" incident on the front page. We also want to analyze this and draw up policy suggestions that can help prepare social measures. In the wake of the Telegram sexual exploitation scandal, The National Assembly is quickly proposing related bills. However, the reality is that even a clear concept and definition of "Digital sexual Crimes" have not been made yet. The effective support system for victims is also insufficient. Therefore, this paper examines the definition and concept of child sexual exploitation and harassment. We will look at the features, causes, and conditions. In addition, it will examine the current status of Digital Sexual Crimes distribution and deletion of domestic, foreign platforms. Major foreign countries, including the U. S. A. refer to cases in which big data and artificial intelligence technologies are actively used to protect victims and track perpetrators.

• Journal of Korea Game Society
• /
• v.7 no.2
• /
• pp.83-90
• /
• 2007

One result of the trend towards globalization is an increased number of projects that focus on natural language processing. Automatic speech recognition (ASR) technologies, for example, hold great promise in facilitating global communications and collaborations. Unfortunately, to date, most research projects focus on single widely spoken languages. Therefore, the cost to adapt a particular ASR tool for use with other languages is often prohibitive. This work takes a more general approach. We propose an International Phoneticizing Engine (IPE) that interprets input files supplied in our Phonetic Language Identity (PLI) format to build a dictionary. IPE is language independent and rule based. It operates by decomposing the dictionary creation process into a set of well-defined steps. These steps reduce rule conflicts, allow for rule creation by people without linguistics training, and optimize run-time efficiency. Dictionaries created by the IPE can be used with the speech recognition system. IPE defines an easy-to-use systematic approach that can obtained 92.55% for the recognition rate of Korean speech and 89.93% for English.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.8
• /
• pp.72-83
• /
• 2017

This study was conducted to investigate nursing students' safety-climate: perception and performance of standard precautions for healthcare-associated infection control. We also identified actors influencing performance of standard precautions. Data were collected from 246 junior and senior nursing students at nine colleges in D city from July to September, 2016. The mean score of performance was significantly lower than that of perception in all areas of standard precautions. The biggest difference between perception and performance was in the usage of personal protective equipment and safe injection practices. We also detected significant positive correlations among safety-climate, perception, and performance of standard precautions. In the regression analysis, performance of standard precautions was influenced by safety-climate and grade accounting for 10.7% of variance. To improve healthcare-associated infection control among nursing students, safer and more supportive practical environments need to be provided, and new training strategies such as simulation education need to be expanded.