• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.458-461
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• 2005

In this paper, a new type of inchworm motion actuator is developed in fabrication of actuators for micro-press machine. This is consisted of three piezoelectric actuators, one is for moving the tool guide and the other are for clamping the guide. The inchworm motor provides both high load and large displacement in small size actuator. PZT has compressive strength and often fails under tensile stress and pulling. Thus, in order to prevent failure, we have designed pre-load housing and accomplished FEM analysis. The pre-load housing was used for determining the optimal design condition by comparing the von-mises stresses with the change of hinge stiffness. Also, in order to predict the performance of the motor under certain conditions, the system model was simulated using MATLAB. This is open loop control actuator and driven by the period of input voltage.

• 한국가구학회지
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• 제27권3호
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• pp.165-174
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• 2016

To modularize the joints of Hanok, the bending strengths of butterfly joints between pre-cut and manual member were compared. Structural size joints were manufactured and the length, width and thickness of each tenon were produced with different sizes. The ultimate load of pre-cut members was 2 times higher than that of manual members. Degree of anchorage for the joints on pre-cut member was also superior to that of manual member. By the F-test results, a great influence between ultimate load and sizes of tenon was found. In result of multiple regression analysis, the length and thickness of tenon were showed proportion relationships with the ultimate load, but the width of tenon was showed inverse proportion with the ultimate load. The results of this study can be used to identify the relationships among the major influence factors. Futhermore, it might be used as basic data for modularization the joints of Hanok.

• 한국공작기계학회논문집
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• 제18권2호
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• pp.137-143
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• 2009

This paper presents the fabrication of inchworm motor for high precision actuator system of large displacement and high force. The inchworm motor consists of a extend actuator that provides displacement of tool guide and two clamping actuators which provide the holding force. In order to avoid the PZT fracture, design of pre-load housing was conducted by flexure hinge structure, because PZT actuator has low tensile and shear. To design the pre-load housing and optimize the clamping mechanism, the static and dynamic analysis were conducted by finite element method. From these results, a prototype of the inchworm motor was fabricated and dynamic characteristic with respect to the various frequency was tested. The maximum velocity of the inchworm motor was $41.1{\mu}m/s$ at 16Hz.

• Journal of the Korean Wood Science and Technology
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• 제44권5호
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• pp.664-676
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• 2016

최근 여러 사회적인 변화에 따라 한옥에 대한 수요가 증가하고 있다. 하지만 한옥은 수가공으로 인한 가격 상승의 큰 문제점을 가지고 있다. 따라서 한옥 접합부의 모듈화를 위해 기계가공과 수가공과의 성능비교를 하였다. 더글라스퍼를 이용하여 두 가공법으로 실대재 주먹장을 제작하였다. 두 가공법에 대해 휨 성능을 평가하였다. 평균 최대하중은 같은 치수의 그룹을 비교했을 때 기계가공이 수가공에 비해 약 1.5배 더 높았다. 유의성 검증결과 두 가공법 모두 각 요소의 크기변화는 강도에 큰 영향을 미치는 것으로 나타났다. 다중회귀분석을 통해 목길이와 목두께는 최대하중과 비례 관계였으나 목너비는 반비례관계인 것을 알 수 있었다. 본 연구는 한옥 접합부를 모듈화 함에 있어 기초자료로 사용할 수 있을 것이다.

• 한국축산시설환경학회지
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• 제15권1호
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• pp.17-28
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• 2009

PEB system is more economical when compared with structures commonly used Hot rolled and welded light H-beam was introduced in the Standard Livestock Housing. This study suggested more economical technology for structural design by the reduction of live load, relief of deflection limit and reduction of importance factor. And, when applying wind Load as a result of examination with Low Rise Building Systems Manual considering open model, we can know that when the wind load is big, enclosed model is more stable than open model. In short, Suggesting more economical model and providing the method to reduce natural disaster, by the application of PEB system and the development of technology for structural design, are considered to strengthen the competitive power of farmhouse.

• 한국주거학회논문집
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• 제2권2호
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• pp.35-40
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• 1991

In this study, the operation(heating) period of heat source(boiler) machineries in apartment building for periodic heat load analysis has been established by investigating their heat source machineries actural operation period, energy consumption, the capacity of heat source machineries, and their building element. Thus, the purpose of this paper is at bring up the various pre-estimate expression for energy conservatiove, efficient operation and amount of water supplied.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.31-36
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• 2002

Even through the problem of misalignment is of great importance, not much work has been reported in the literature on the effect of misalignment on the vibrations of the gear-bearing systems. Therefore, the nonlinear dynamic characteristics of the gear drive system due to misalignment are investigated in this work. Transmission error for helical gear and bearing nonlinear stiffness is calculated. The equation of motion of the gear drive system is modelled using the time-varying gear meshing stiffness, bearing nonlinear stiffness, and bearing pre-load due to the housing deformation. Numerical analysis lot the gear drive system show the result of misalignment effect - sub-harmonic component, bearing pre-load effect, and another nonlinear phenomenon. And the numerical analysis are verified by the experimental result.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.467-472
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• 2010

Individual vacuum pressure method is soft ground improvement technique, in which a vacuum pressure can be directly applied to the vertical drain board to promote consolidation and strengthening the soft ground. This method does not require a surcharge load, different to embankment or pre-loading method. In this study, given the inner displacement of the ground where the individual vacuum pressure is applied, this dissertation aimed to reproduce the state of stress in the ground that is subject to the constraints created by the depth of improvement area. Modified Cam Clay theory which made it possible to take into account the isotropic displacement of the ground was applied to the NAP-IVP used simulation; the conception of equivalent permeability proposed by Hird was also applied so that the 3-dimensional real construction effect of drain materials could be reflected in the analysis.

• 토지주택연구
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• 제12권3호
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• pp.87-96
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• 2021

국내는 유럽에서 널리 사용하고 있는 헬리컬 파일을 많이 사용하기 시작하였지만, 헬리컬 파일의 설계기준을 만들려고 하는 노력이 부족하여, 여전히 헬리컬 파일의 표준설계기준을 가지고 있지 못하다. 따라서, 본 연구는 현장에서 헬리컬 파일을 시공하고 재하시험을 실시한 후, 이전 데이터를 포함하여 신뢰도 분석을 실시하였다. 그 결과 매입 말뚝에 대한 도로교설계기준 식이 수정 Davisson 분석법과 연계하여 좋은 신뢰도와 일관성을 보여주었는데, 이 설계식의 저항편향계수가 '1.0'에 가까웠고 변동성도 '낮음' 수준을 보여 주었기 때문이다.

• 한국공작기계학회논문집
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• 제10권1호
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• pp.23-29
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• 2001

Cylindrical type of self-controlled restrictor are designed for hydrostatic bearing of grinding wheel spindle. Typical hydrostatic journal bearing with the designed restrictor is analytically model. According to the model, the affect of oper-ation parameters, such as, initial cross distance, supply pressure, diameter of two supply holes, pre-load of spring, and clearance between spindle and housing, on bearing stiffness are analyzed. From the results of the analysis, the optimum conditions of operation parameters that maximize the bearing stiffness are estimated.