• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.3
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• pp.45-56
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• 2011

Hyper Text Transfer Protocol(HTTP) is widely used in nearly every network when people access web pages, therefore HTTP traffic is usually allowed by local security policies to pass though firewalls and other gateway security devices without examination. However this characteristic can be used by malicious people. With the help of HTTP tunnel applications, malicious people can transmit data within HTTP in order to circumvent local security policies. Thus it is quite important to distinguish between regular HTTP traffic and tunneled HTTP traffic. Our work of HTTP tunnel detection is based on Support Vector Machines. The experimental results show the high accuracy of HTTP tunnel detection. Moreover, being trained once, our work of HTTP tunnel detection can be applied to other places without training any more.

• Journal of Platform Technology
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• v.11 no.4
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• pp.80-88
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• 2023

To construct a learning model in the field of artificial intelligence, a dataset should be collected and be delivered to the central server where the learning model is constructed. Federated learning is a machine learning method building a global learning model without transmitting data located in a client side in a collaborative manner. It can be used to protect privacy, and after constructing a local trained model on individual clients, the parameters of the local model are aggregated centrally to update the global model. In this paper, we reuse the existing learning parameter to improve federated learning, describe incremental federated learning. For this work, we do experiments using the federated learning framework named Flower, and evaluate the experiment results with regard to elapsed time and precision when executing optimization algorithms.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.591-593
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• 2022

This paper proposes a partial offloading system for minimizing application service processing latency in an FEC (Fog/Edge Computing) environment, and it analyzes the offloading effect of the proposed system against local-only and edge-server-only processing based on network load. A partial offloading algorithm based on reconstruction linearization of multi-branch structures is included in the proposed system, as is an optimal collaboration algorithm between mobile devices and edge servers [1,2]. The experiment was conducted by applying layer scheduling to a logical CNN model with a DAG topology. When compared to local or edge-only executions, experimental results show that the proposed system always provides efficient task processing strategies and processing latency.

• The Korean Journal of Archival Studies
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• no.32
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• pp.3-44
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• 2012

The purpose of the study is to explore the strategies to build participatory digital archives for documenting localities. Following the introduction of the chapter one, the chapter two deals with categorizing participation types of persons and organizations for documenting localities, analysing characteristics and benefits of each type, and listing up the requirements of participatory archives based on literature reviews. The chapter three focuses on the analyses of digital archives especially based on the participation of organizations such as collecting institutions and community archives in USA, Canada and UK. The cases of participatory archives are divided into two types; i) digital archives based on archival collections of institutions such as libraries, archives, and museums, ii) digital archives mainly based on various community archives. Online Archives California(OAC) and Calisphere of University of California, MemoryBC of British Columbia of Canada, and People's Collection Wales of UK as the first type cases, and Connecting Histories of Birmingham, 'Community Archives Wales(CAW), Cambridgeshire Community Archive Network(CCAN), Norfolk Community Archives Network(NORCAN) as the second type cases are selected for comparative analyses. All these cases can be considered as archival portals since they cover collections from various organizations. This study then evaluates how these digital archives fulfill the requirements of participatory archives such as : i) integrated search of archives that are to be distributed, ii) participation of individuals and organizations, and iii) providing broader contextual information and representation of context as well as contents of archives. Lastly the final chapter suggests the implications for building participatory archives in Korean local areas based on following aspects : host organizations and implementation strategy, networks of collection institutions and community archives, preserving and reorganizing contextual information, selection and appraisal, and participation of records users and creators.

• Journal of Popular Narrative
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• v.26 no.3
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• pp.161-188
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• 2020

This paper seeks to expand the scale of literary history by restoring and analyzing the whole aspect of Kwak Hashin's works, which has so far been studied little. For this purpose, I notice the rupture of discontinuity of his works which is greatly divided into the colonial period and post Korean war period. And the characteristics of each works can be analyzed based on the three axis, local(colonial period), jobless person(post-war period), and Homo Economicus(some short stories, and popular novels in post-war period). In Chapter 2, 'Local-the world of Munjang', I evaluated that Kwak Hashin's novel, which had been published in the late 1930s in the Journal of Munjang, embodied anti-modern aesthetic consciousness, as clearly revealing the sorrow for disappearing things, the pre-modern sense of time, and the preference for local. In Chapter 3, 'Jobless Person' and Chapter 4, 'The State of All People's Struggle against All People, The Appearance of Homo Economicus', the Korean society in late 1950s, which entered underdeveloped capitalist countries after Korean war, can be characterized by two contrasting male-gender, one is the jobless, incompetent male, and the economic man on the other hand. In the late '50s, Lumpen(=Jobless Person) novels showed the problems of the Korean economy through incompetent male character. The intelligent men took the path to survival rather than morality or intimacy, projecting their own incompetence and anxiety to women/wives. In the popular novels Women's Song and The Shadow of the Fig Tree, achievement-oriented male figures who betrayed their colleagues, and exploited women's sex by using love relationships to rise to the top appeared. They can be defined as the Homo Economicus who embody the state of universal struggle against all people. These novels showed the formation of the masculinity in post Korean war period, which pursued the survival of the fittest, borrowing form of popular novel. As we have seen so far, Kwak Hashin needs to be re-evaluated as an writer who expanded the modern literary history in the outside of literature. He was the last generation writer written in Korean late colonial period, and provided the model of postwar literature by borrowing the form of journalism and popular novels.

• Korean Chemical Engineering Research
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• v.58 no.3
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• pp.430-437
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• 2020

In this research, the anti-windup techniques for the cascade control system are newly developed. Cascade control system has an additional internal feedback control loop to reject disturbances better than the conventional control system. Remarkable difference between the conventional single-loop control system and the cascade control system is the interaction that the controller output saturation of the secondary control loop strongly affects the integral action of the primary control loop. In industry, local back calculation anti-windup method has been mainly used for each controller without considering the interaction between the two controllers. But it cannot eliminate the integral-windup of the primary controller originated from the saturation of the secondary controller output. To solve the problem, the two anti-windup techniques of the cascade conditional integration and the cascade back calculation are proposed in this research by extending the local anti-windup techniques for the single-loop control system to the cascade control system. Simulation confirmed that the proposed methods can effectively remove the integral windup of the primary controller caused by the saturation of the secondary controller output and show good control performances for various types of processes and controllers. If the reliability of the proposed methods is proved through the applications to real processes in the future, they would highly contribute to improving the control performances of the cascade control system in industry.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.6
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• pp.25-35
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• 1998

The control system architecture in switching systems have undergone numerous changes to provide various call processing capability needed in telecommunication services. During call processing in a distributed switching control environment, the delay effect due to communication among main processors or peripheral controllers is one of the limiting factors which affect the system performance. In this paper, we propose a performance model for an IPC(Inter Processor Communication) interface hardware block which is required on the ATM cell-based message processing in a distributed ATM exchange system, and analyze the primary causes which affect the processor performance through the simulation. Consequently, It can be shown that the local CPU of the several components(resources) related to the IPC scheme is a bottleneck factor in achieving the maximum system performance from the simulation results, such as the utilization of each processing component according to the change of the input message rate, and the queue length and processing delay according to input message rate. And we also give some useful results such as the maximum message processing capacity according to the change of the performance of local CPU, and the local CPU maximum throughput according to the change of average message length, which is applicable as a reference data for the improvement or expansion of the ATM control system.

• Journal of Digital Contents Society
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• v.10 no.4
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• pp.509-520
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• 2009

The advancement of network & application technology causes a major change for the use of IT(Information Technology) equipment, including computer and mobile system. In the process from beginning with main frame in the 1960s and 70's, through the server-client paradigm in the 1980s and toward the development of network computer since 90's, computer systems are now evolutioning from isolated physical system to complementary network based virtual system[1][2]. In network based computer system, application and data required for operation are stored at not client as local system, but at server[1]. User can use application & data on a server as if those are on a local client, and a client is now toward a developing thin and network friendly system. In this paper, we discuss possible ways for the efficient implementation of thin-client. For the use of remote application & data as if in local environment, we make use of X protocol. Unlike formal simple Client - Server paradigm, we design a Proxy for middle-tier server for the improvement of QoS and session persistence. X server, Xvfb(X virtual frame buffer) are implemented on thin client and Server, respectively and we applied XSMP(X Session Management Protocol) to our framework for session management. In the end, beyond simple transfer of server display, we suggest thin client framework for the transfter of remote server application over internet.

• Journal of the Korean association of regional geographers
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• v.16 no.4
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• pp.355-368
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• 2010

This study is to make a framework of newly interpretating the dynamic change of regional or local landscape rapidly occurred after the establishment of the nation state and capitalistic system. The basic concepts of making an interpretative framework are power, subjectivity, and performativity. The framework of closely interrelating the three concepts developed in the near future will be applied to the interpretation of variety of (de)centralized landscapes in regions or locals. A centralized political power under the nation state has destroyed or marginalized the historically developed landscapes, traditional culture, and subjects' values in regions or locals by the political implementation of the nation state, the establishment of national identity, a centralized economic development, and so on. The landscapes produced by the political power of the nation state can take a role as a cause of conflicts in regions or locals in terms of a historical perspective. Landscapes are being made by various subjects, and the produced landscapes also positively or negatively will influence the emotion, cognition, and behavior of the subjects particularly in a performative perspective. The dynamics interrelation between subjects and landscapes has been disguised or marginalized by reason/rationality, totality/collectivity, the separation between reason and emotion mainly made by modernism, the nation state, a capitalistic system. The interrelation between landscapes and subjects is especially emphasized on people's resistibility and creativity. Lastly, landscape is not a concept given as a priori or (re)presented objectively. It is not also a material or an object independently existed from a subject's emotion and cognition. It should be interpreted through a performative relation with subjects. Performativity will take an active role of combining the materiality of landscape, power, and subjectivity. It is also important to understand the active role of landscapes.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.370-374
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• 2006

Ad-hoc 환경의 응용은 재난구조나 회의실 또는 강의실에서의 정보 교환과 같은 그룹 통에서 이용된다. Ad-hoc 환경은 무선 채널을 이용하므로 상대적인 낮은 대역폭과 높은 오류 발생률을 가지게 된다. 따라서 Ad-hoc 네트워크에서는 신뢰적인 전송이 요구된다. 이동 노드는 상대적으로 낮은 성능과 에너지의 제한으로 인해 유선 환경과 같은 신뢰적인 전송 기법을 Ad-hoc 환경에 적용하기에는 문제가 발생한다. Ad-hoc 환경의 무선 채널이 가지는 보안적인 취약성과 높은 에러율을 극복하는 신뢰적인 그룹 키 전송을 위한 재전송 기법을 제안한다. 신뢰적인 트리 형성하기 위해 n차 트리 구조를 이용한다. 손실 감지를 위한 ACK 메시지를 이용하고 손실 복구를 위한 재전송 기법에 대해 연구를 한다. 제안한 신뢰적인 그룹 키 전송을 위한 재전송 기법은 트리의 깊이의 차수가 루트 관리 노드, 서브 관리 노드와 로컬 멤버 노드로 구성되기 때문에 손실 감지와 손실 복구에 대한 연산의 오버헤드가 적다. 루트 관리 노드는 멤버 노드로부터 받은 개인키 정보를 이용하여 그룹 키를 생성하고 그룹 키 부분 정보를 서브 관리 노드에게 전송하고 서브 관리 노드에 대한 신뢰성을 책임진다. 서브 관리 노드는 루트 관리 노드로부터 받은 그룹 키 부분 정보를 로컬 멤버 노드에게 전송하고 로컬 멤버 노드에 대한 신뢰성을 책임진다. 루트 관리 노드와 서브 관리 노드를 관리 노드라 한다. 관리 노드가 신뢰적인 전송을 위해 관리하는 멤버 노드는 전체 그룹에 독립적으로 유지 가능하므로 확장성 및 효율성이 좋다. 관리 노드는 동적인 그룹에 따른 타이머를 설정함으로써 손실 감지에 대한 시간을 줄임으로써 효율적인 손실 감지 및 손실 복구를 한다. 임계값 설정으로 인한 중복 수신에 대한 오버헤드를 줄일 수 있다.신뢰성을 향상 시킬 수 있는 Load Balancing System을 제안한다.할 때 가장 효과적인 라우팅 프로토콜이라고 할 수 있다.iRNA 상의 의존관계를 분석할 수 있었다.수안보 등 지역에서 나타난다 이러한 이상대 주변에는 대개 온천이 발달되어 있었거나 새로 개발되어 있는 곳이다. 온천에 이용하고 있는 시추공의 자료는 배제하였으나 온천이응으로 직접적으로 영향을 받지 않은 시추공의 자료는 사용하였다 이러한 온천 주변 지역이라 하더라도 실제는 온천의 pumping 으로 인한 대류현상으로 주변 일대의 온도를 올려놓았기 때문에 비교적 높은 지열류량 값을 보인다. 한편 한반도 남동부 일대는 이번 추가된 자료에 의해 새로운 지열류량 분포 변화가 나타났다 강원 북부 오색온천지역 부근에서 높은 지열류량 분포를 보이며 또한 우리나라 대단층 중의 하나인 양산단층과 같은 방향으로 발달한 밀양단층, 모량단층, 동래단층 등 주변부로 NNE-SSW 방향의 지열류량 이상대가 발달한다. 이것으로 볼 때 지열류량은 지질구조와 무관하지 않음을 파악할 수 있다. 특히 이러한 단층대 주변은 지열수의 순환이 깊은 심도까지 가능하므로 이러한 대류현상으로 지표부근까지 높은 지온 전달이 되어 나타나는 것으로 판단된다.의 안정된 방사성표지효율을 보였다. $^{99m}Tc$-transferrin을 이용한 감염영상을 성공적으로 얻을 수 있었으며, $^{67}Ga$-citrate 영상과 비교하여 더 빠른 시간 안에 우수한 영상을 얻을 수 있었다. 그러므로 $^{99m}Tc$-transierrin이 감염 병소의 영상진단에 사용될 수 있을 것으로 기대된다.리를 정량화 하였다. 특히 선조체에서의 도파민 유리에 의한 수용체 결합능의 감소는 흡연에 의한 혈중 니코틴의 축