• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6C
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• pp.221-229
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• 2011

A core zone of a fill dam is an important part of a dam for cutoff of water. Therefore, the material properties and behavior characteristics of a core zone are very important factors in an analysis of dam stability. However, the investigation on material properties of actual dam core is extremely rare so far. The material properties have been acquired or estimated by indirect methods like a surface wave surveying or empirical equation. In this research, in-situ and laboratory tests were conducted during dismantling an existing dam directly to investigate characteristics of the core zone in terms of the depth and transient variation of properties after construction of the dam. Dynamic material properties like shear wave velocity and shear modulus were measured and compared to other existing empirical correlations. In addition, aging characteristics of dynamic material properties were investigated by a series of laboratory tests.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.319-320
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• 2013

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.211-213
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• 2004

차세대 인터넷 사용자들을 위해서는 이동하면서 연속적으로 인터넷에 접속하고 통신할 수 있도록 지원하는 것이 필수적이다. 현재까지 Mobile IT를 기점으로 다양한 네트워크 계층에서의 이동성 지원 프로토콜들이 제안되어 왔다. 그런데 최근에는 네트워크 계층에서의 이동성 지원과는 전혀 다른 접근 방식으로서, 트랜스포트 계층에서 이동성을 지원하는 방안이 언급되고 있다. 트랜스포트 계층에서의 이동성 지원은 기존 네트워크 계층에서의 이동성 지원 방안처럼 코어 네트워크에 홈 에이전트나 외부 에이전트와 같은 특별한 엔터티들의 추가를 요구하지 않기 때문에 디플로이가 상대적으로 용이하며, 종단 간 이동성을 지원할 수 있기 때문에 네트워크 계층에서의 이동성 지원 방안에서 발생하는 터널링 오버헤드나 비효율적인 라우팅 문제를 피할 수 있다. 이에 본 논문에서는 차세대 인터넷 환경인 IPv6 네트워크에서 WLAN 기반의 트랜스포트 계층 이동성 지원 방안을 제안한다 시뮬레이션을 통하여 제안하는 방안이 네트워크 계층에서의 이동성 지원과 대등한 성능을 보임을 확인하였고, 특히 이동 노드의 속도가 빠를 때 새로운 네트워크에서의 IT 주소 획득 시간이 길 때, 네트워크 계층에서의 이동성 지원 방안보다 더 좋은 성능을 제공함을 볼 수 있었다.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.747-750
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• 2008

본 연구는 온톨로지, 자연어 처리, 메타데이터 등의 시맨틱 웹 기반 기술들을 이용하여 시맨틱 웹 응용을 위한 전체적인 기술 적용과 그의 활용에 목적을 두고 있다. 이를 위해 OWL을 기반으로 조직이나 기관의 지식 주제별 도메인 온톨로지와, 기존 워드넷(WordNet)이나 더브린 코어 메타데이터(Dublin Core Meta Data)와 조직에 정의된 데이터베이스의 스키마를 MDR로 구축하여 상호 연결하여 온톨로지가 갖는 지능적 추론과 규칙 서비스와 표준화된 메타데이터의 결합 방법을 제공한다. 이는 기존에 온톨로지와 메타데이터의 재활용과 연결(Alignment)에 있어 연구적으로 높은 가치가 있다. 그리고 조직의 사용자가 문서를 작성할 때 문서의 내용에 대해 자연어 처리 기술과 온톨로지의 기술을 이용해 적합한 용어나 메타데이터를 자동으로 제공하여 작성된 문서의 공유와 재사용성을 높이고, 작성된 문서를 XML 형식으로 구성되는 XML 기반 지능 문서 데이터베이스(XMB Based Intelligent Document Database)에 저장하여 유사한 문서를 작성하거나 사용할 필요가 있는 사용자에게 문서 등록과 검색 에이전트(Document Registry and Retrieval Agent)를 통해 이러한 제공하여 문서 지식의 사유화를 최소화 하고, 유사 문서의 재작성과 또는 특정 문서의 작성에 필요한 시간이나 경비를 줄이게 된다. 또한 웹상이나 PDA 같은 개인 휴대장치를 통해서도 서 등록과 검색 에이전트를 통해 문서를 검색하고 사용할 수 있게 한다면 언제 어디서나 해당 서비스를 활용하는 유비쿼터스와 시맨틱 웹의 실질적 응용을 거둘 수도 있으리라 사료된다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.11
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• pp.103-108
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• 2019

The cooling rate and the uniformity of mold temperature, in the injection molding process, possess great influences on the productivity and quality of replications. The conformal cooling channel, which is of a uniform spacing from the mold cavity by the metal additive manufacturing process, receives much attention recently. The purpose of this study is to develop a mold core with a curved conformal cooling channel for a pottery-shaped thick-wall cosmetic container through the hybrid method of direct metal tooling (DMT) process. In this study, we design a mold core that contains the curved cooling channel for the container. A method that divides the cavity is proposed and the DMT process is carried out to form the curved cooling channel. The test mold core, with the curved conformal cooling channel, has been fabricated by the proposed method to confirm the feasibility of the design concept. We show that no leakage is observed for the additive manufactured test mold core, and its physical properties demonstrate that it can be sufficiently used as the injection mold core.

• Annual Conference on Human and Language Technology
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• 2023.10a
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• pp.91-94
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• 2023

자연스러운 상호작용이 가능한 인공지능 에이전트를 개발하기 위해서는 언어적 표현뿐 아니라, 비언어적 표현 또한 고려되어야 한다. 본 논문에서는 한국어 발화문으로부터 비언어적 표현인 모션을 생성하는 연구를 소개한다. 유튜브 영상으로부터 데이터셋을 구축하고, Text to Motion의 기존 모델인 T2M-GPT와 이종 모달리티 데이터를 연계 학습한 VL-KE-T5의 언어 인코더를 활용하여 구현한 모델로 실험을 진행하였다. 실험 결과, 한국어 발화 텍스트에 대해 생성된 모션 표현은 FID 스코어 0.11의 성능으로 나타났으며, 한국어 발화 정보 기반 비언어 표현 정보 생성의 가능성을 보여주었다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.7
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• pp.41-51
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• 2020

This paper presents the development of a robotic system for rehabilitation of the trunk's ability to maintain postural control under different balance conditions. The system, developed with extensive input from rehabilitation and biomedical engineering experts, consists of a seat mounted on a robotic mechanism capable of moving it with four degrees of freedom (3 rotational and 1 translational). The seat surface has built in instrumentation to gauge the movements of the user's center of pressure (COP) and it can be moved either to track the movements of the COP or according to operator given commands. The system allows two types of leg support. A ground mounted footrest allows participation of legs in postural control while a seat connected footrest constrains the leg movement and limits their involvement in postural control. The design evolution over several prototypes is presented and computer aided structural analysis is used to determine the feasibility of the designed components. The system is pilot tested by a stroke patient and is determined to have potential for use as a trunk rehabilitation tool. Future works involve more detailed studies to evaluate the effects of using this system and to determine its efficacy as a rehabilitation tool.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.3
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• pp.660-672
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• 2011

The Web is widely used to share information, utilizing the client-server model. In the client-server model, since the server only responds according to explicit requests from the client, the model seems hard to support sharing of massive information rapidly changing in today's Internet. The technology known as Server Push enables the server to actively provide information to clients without explicit requests from the clients using Web pages. Although various studies have been done to realize the Server Push technologies, there are many problems in the development of push application without push engines which support infrastructures for the effective development of push application. In this paper, we develop JPE(Java Push Engine) which presents the effective support for push services over the Internet. JPE is composed of two main components: the JPE Core supporting Epoll and the JPE Library supporting asynchronous communication. In addition, JPE defines various push functions and provides programming interfaces supporting the functions. Push applications developed using JPE effectively manages client connections with Epoll mechanism, providing push services through AJAX-based asynchronous communication.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.12
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• pp.2569-2578
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• 2009

Core-A microprocessor is the all-Korean product designed as 32-bit embedded RISC microprocessor developed by KAIST and supported by the Industrial Property Office. This paper analyze Core-A microprocessor architecture and proposes efficient method to interface Core-A microprocessor with coprocessor. To verify proposed interfacing method, the AES cryptography processor that has 128-bit key and block size is used as a coprocessor. Coprocessor and AES are written in Verilog-HDL and verified using Modelsim simulator. It except AES module consists of about 3,743 gates and its maximum operating frequency is about 90Mhz under 0.35um CMOS technology. The proposed coprocessor interface architecture is efficiency to send data or to receive data from Core-A to coprocessor.

• Journal of the Korean Institute of Gas
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• v.26 no.2
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• pp.1-8
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• 2022

The purpose of this study is to prepare GPTMS((3-Glycidoxypropyl) trimethoxysilane)-SiO₂ nanofluid and analyze the effect of nanofluid injection on carbonate reservoirs. Structural analysis of silica nanoparticles modified by GPTMS was investigated by FTIR(Fourier transform infrared spectroscopy). C-H stretching vibrations at 2,950 cm^-1 indicating the silica surface modification with GPTMS were observed when the silane feed was over 0.5 mmol/g. Also, the coreflooding test by nanofluid injection on the aged limestone and dolomite plug samples was carried out with different particle concentration and flow rate. The incremental oil recovery was up to 18.9%, and contact angle and permeability of carbonate samples were changed by the effect of nanoparticle adsorption on pore which caused wettability alteration and pore size change. Therefore, the prepared nanofluid will be utilized as an injection fluid for enhancing oil recovery and modifying fluid flow properties such as change of rock wettability and permeability in carbonate reservoirs.