• 한국지구과학회지
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• 제43권5호
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• pp.569-578
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• 2022

백악기 중기, 세노마눔절-투로니아절에 발생한 해양 무산소 사건인 Oceanic Anoxic Event 2 (OAE2)는 다량의 유기물을 포함한 흑색셰일이 전세계적으로 퇴적된 단기간의 탄소 순환 교란 사건이다. 백악기 후기의 온실 지구의 환경(높은 CO₂농도, 고해수면, 해양의 무산소 환경 확장)은 탄소, 황 및 여타 주요 원소의 생지화학 순환의 교란과 밀접하게 상호 작용하였다. 1970년대 최초 명명 이후 동위원소를 포함한 화학적 지시자 연구가 활발하게 진행되었으며, 그 결과 화산 활동과 해양 표층의 유기물 생산 증가가 무산소 환경 발달의 주된 원인으로 여겨진다. 본 논평에서는 OAE2의 기작을 탄소 및 황, 미량 금속원소의 순환을 중심으로 살펴보고자 한다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제8권1호
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• pp.11-17
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• 2008

Typical wireless sensor networks used in structural monitoring are continuous types wherein data transmission is progressive at all time that may include irrelevant and insignificant data and information. Continuous types of wireless monitoring systems often pose problems of handling large-sized data that may deteriorate the performance of the system. The proposed method is to suggest an event-triggered monitoring system that captures and transmits relevant data only. An error signal generated by the Principal Components Analysis (PCA) is utilized as an index for event detection and selective data transmission. With this new monitoring scheme, the remote server is relieved of unwanted data by receiving only relevant information from the wireless sensor networks. The performance of the proposed scheme was verified with simulation studies.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제16권12호
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• pp.1229-1233
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• 2010

이벤트 기반 무선 센서 네트워크에서 주기적인 센싱 데이터에 비해 높은 전송률과 우선순위를 갖는 이벤트 데이터가 병목 구간에 집중되면 네트워크 혼잡이 발생한다. 혼잡이 지속되면 대부분의 데이터가 손실되는 네트워크 붕괴 현상이 나타난다. 전송률 조절 기법은 이러한 네트워크 붕괴 현상을 막기 위한 해결책 중 하나이다. 본 논문에서는 무선 센서 네트워크에서의 혼잡 제어를 위해 각 노드에서 혼잡 패턴에 따라 자식 노드의 전송률을 조절하는 기법을 제안한다. 실험을 통해 제안하는 기법이 효과적으로 혼잡을 제어하고, 기존의 전송률 조절 기법들보다 더 많은 이벤트 데이터를 전송함을 확인하였다.

• 영어영문학
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• 제56권6호
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• pp.1311-1337
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• 2010

This paper deals with one of the hottest debates in the history of the Association for Asian American Studies (AAAS) since its inception in the late 1960s. In 1998 at Hawai'i, the AAAS awarded Lois-Ann Yamanaka its Fiction Award for her novel Blu's Hanging, only to have this award protested. The point at issue was the inappropriate representation of Filipino American characters called "Human Rats" in the novel. This event divided the association into two groups: one criticizing the novel for the problematic portrayal of Filipinos in colonial Hawai'i, and the other defending it from the criticism in the name of aesthetic freedom. Such a "crisis of representation" in Asian American identity reflects on the ways in which local Hawaiians are positioned in the complicate power dynamic between oppositional Hawaiian identity and cosmopolitan diasporic identity within the larger framework of Asian American pan-ethnic identity. The controversial event triggered the eruption of Asian Americans' anxiety over the identity-bounded nation of Asian America where intra-racial classism and conflict have been at play, which are primary themes of Blu's Hanging. This paper shows how Yamanaka's Blu's Hanging becomes so disturbing a work to prevent the hegemonic formality of Asian America identity from being fully dogmatic. Ultimately, it contradicts the political unconscious of the reading public and unmasked its false consciousness by engendering a "free subjective intervention" in the ideological reality of colonial Hawai'i.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.236-246
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• 2003

This paper is implemented a control algorithm in order to be stable and minimized to entire train traffic system at delayed case. Signal ing system is described wi th algebraic equations given for train headway, Discrete-event simulation principles are reviewed and a demonstration block signaling model using the technique is implemented. Train congestion at station entrance for short headway operation is demonstrated and the propagation of delays along a platform of trains from any imposed delay to the leading train is also shown. A rail way signaling system is by nature a distributed operation with event triggered at discrete intervals. Although the train kinematic variables of position, velocity, and acceleration are continually changing, the changes are triggered when the trains pass over section boundaries and arrive at signals and route switches. This paper deals with linear-mode1ing, stability and optimal control for the traffic on such metro line of the model is reconstructed in order to adapt the circuits. This paper propose optimal control laws wi th state feedback ensuring the stability of the modeled system for circuits. Simulation results show the benefit to be expected from an efficient traffic control. The main results are summarized as follows: 1. In this paper we develop a linear model describing the traffic for both loop lines, two state space equations have been analyzed. The first one is adapted to the situation where a complete nominal time schedule is available while second one is adapted when only the nominal time interval between trains is known, in both cases we show the unstability of the traffic when the proceeding train is delayed following properties, - They are easily implemented at law cost on existing lines. - They ensure the exponetial stability of loop system. 2. These control laws have been tested on a traffic simulation software taking into the non-linearites and the physical constraints on a metro line. By means of simulation, the efficiency of the proposed optimal control laws are shown.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 추계학술대회
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• pp.659-662
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• 2012

본 논문에서는 위험지역이나 관리대상 지역의 긴급 상황을 시스템이 자율적으로 경찰 또는 경찰차로 알리며 상황정보를 전달 할 수 있는 상황인지 서비스 시스템을 제안한다. 제안하는 시스템은 gateway로부터 지속적으로 노드들의 위치를 확인하며 대기하다가 상황인지 시스템의 서버에서 이벤트가 발생할 경우 이벤트가 발생한 인근의 노드에게 이벤트 발생 메시지와 영상메시지를 전송시키는 시스템이다. 실험결과, 상황인지 서버에서 이벤트가 발생할 경우 서버에 저장된 경로대로 영상 메시지를 전송하는 것을 확인하였다.

• 센서학회지
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• 제22권1호
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• pp.18-27
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• 2013

Real-time monitoring is one of the prime necessities in a weapon flight test that is required for the efficient and timely collection of large amounts of high-rate sampled data acquired by an event-trigger. The wireless sensor network is a good candidate to resolve this requirement, especially considering the inhospitable environment of a weapon flight test. In this paper, we propose a priority based multi-channel MAC protocol with CSMA/CA over a single radio for a real-time monitoring of a weapon flight test. Multi-channel transmissions of nodes can improve the network performance in wireless sensor networks. Our proposed MAC protocol has two operation modes: Normal mode and Priority Mode. In the normal mode, the node exploits the normal CSMA/CA mechanism. In the priority mode, the node has one of three grades - Class A, B, and C. The node uses a different CSMA/CA mechanism according to its grade that is determined by a signal level. High grade nodes can exploit more channels and lower backoff exponents than low ones, which allow high grade nodes to obtain more transmission opportunities. In addition, it can guarantee successful transmission of important data generated by high grade nodes. Simulation results show that the proposed MAC exhibits excellent performance in an event-triggered real-time application.

• 유통과학연구
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• 제16권10호
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• pp.55-64
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• 2018

Purpose - The most important goal of corporate management is the maximization of firm value in the market. Executives of companies are making effort to increase corporate value and initiate various management strategies, which is to develop the products or service with value. Through these efforts, consumer satisfaction grows and loyalty increases, which leads to the positive change of customer satisfaction index. The purpose of this research is to find out the abnormal return after the KCSI(Korean Customer Satisfaction Index) is announced. Research design, data, and methodology - This research data is collected from 11 years' stock price in KOSPI market and KCSI. The authors analyze the abnormal return triggered by the announcement of KCSI through the event study. Results - First, newly enlisted companies in the KCSI show statistically significant short-term abnormal rate of return. Second, the value of the customer satisfaction index is not the level of customer satisfaction but the direction of the change in the CSI. Conclusion - Customer satisfaction has the important intangible asset in the marketing area. However, firms' investment for CS is not an easy decision, because of the difficulty to measure the effect on corporate market value. This research investigates the change of the market value after the announcement of KCSI. Based on the results, firms have to keep trying to increase KCSI relative to the previous year. And the small company has to struggle for being newly listed in the KCSI.

• Journal of Mechanical Science and Technology
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• 제20권11호
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• pp.1993-2001
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• 2006

The piezoelectric bimorph film, which, as an actuator, can generate more effective displacement than the usual PVDF film, is used to control the turbulent boundary-layer flow. The change of wall pressures inside the turbulent boundary layer is observed by using the multi-channel microphone array flush-mounted on the surface when actuation at the non-dimensional frequency $f_b^+$:=0.008 and 0.028 is applied to the turbulent boundary layer. The wall pressure characteristics by the actuation to produce local displacement are more dominantly influenced by the size of the actuator module than the actuation frequency. The movement of large-scale turbulent structures to the upper layer is found to be the main mechanism of the reduction in the wall- pressure energy spectrum when the 700$700{\nu}/u_{\tau}$-long bimorph film is periodically actuated at the non- dimensional frequency $f_b^+$:=0.008 and 0.028. The biomorph actuator is triggered with the time delay for the active forcing at a single frequency when a 1/8' pressure-type, pin-holed microphone sensor detects the large-amplitude pressure event by the turbulent spot. The wall-pressure energy in the late-transitional boundary layer is partially reduced near the convection wavenumber by the open-loop control based on the large amplitude event.

• 정보처리학회논문지D
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• 제8D권6호
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• pp.823-834
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• 2001

능동 데이터베이스에서의 규칙(rule)은 트리거하는 사건이 감지되면 자동으로 규칙을 트리거하여 데이터베이스의 상태변화에 대응하는 조치를 자동으로 수행한다. 이러한 능동 규칙은 자신을 포함한 서로 다른 규칙을 트리거 할 수 있으므로 종료하지 못하고 연속적으로 실행될 가능성이 있다. 이와 같은 문제는 규칙의 종료 분석을 통해 차단할 수 있으며 규칙의 종료 분석은 규칙의 컴파일 시간에 수행하는 것이 가장 효과적이다. 따라서 이 논문에서는 규칙 종료분석기를 내장한 규칙 컴파일러를 설계하고 그 수행 모델 및 알고리즘을 제안한다. 아울러 제안 모델의 핵심이라 할 수 있는 규칙 종료 분석 알고리즘의 정형화를 통해 제안 모델의 완전성을 검증한다.