• 한국정밀공학회지
• /
• 제31권9호
• /
• pp.813-820
• /
• 2014

This paper presents design and performance validation of a method for motion compensation using fast steering mirror. First of all, the schematics of the Electro Optical/Infra-Red (EO/IR) and step-stare image gathering system for an aerial reconnaissance are introduced. Because of the steering mirror with low inertia so called Back scan mechanism (BSM), the fast step-stare image gathering technique that is required for taking a high-definition still image will be realized. After then, the BSM hardware includes motors and feedback sensors are introduced. Also, the motion profile for BSM will be designed to compensate roll scan motion of the gimbals. At the end of this paper, designed profile and tracking performance of the EO/IR system with BSM will be validated through experiments.

• 대한조선학회논문집
• /
• 제47권2호
• /
• pp.225-232
• /
• 2010

The requirement of design of High-Pressure/High-Temperature(HP/HT) pipelines on an seabed increases in recent years. The need of research on the analysis method to improve the design capacity is increasing. The purpose of this study is the development of the analysis method of thermal buckling of subsea pipeline structures. The analysis method of thermal buckling was established by using the commercial FEM code(ABAQUS) which shows the outstanding performance in non-linear static FE analysis. The developed method has been applied to the installation of subsea pipeline on the offshore project. For a validation, the comparative study has been carried out. This application to offshore project demonstrates the superiority of the analysis method of thermal buckling of subsea pipeline structures and testifies the application to detail design.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2004년도 학술대회지
• /
• pp.188-192
• /
• 2004

A Numerical analysis method is developed in order to compute the flaw and wave field for 2-dimensional floating body in the free roll motion with 3 degrees of freedom. Navier-Stokes and continuity equations are gaverning equations in tire present study. Finite Difference method is introduced to discretize the governing equation. The free surface is traced by the interface tracking method and the grid system is fitted to boundaries including free surface and body surface, which is moving in the flow field. The numerical scheme is based on Maker and Cell method. For the sake of validation of the numerical method, the computed roll decay factors according to tire midship section shapes are compared with measured results. The numerical results are discussed in order to understand the effect of midship section shape on roll motion.

• ETRI Journal
• /
• 제40권1호
• /
• pp.122-132
• /
• 2018

This paper proposes a hierarchical dual filtering (HDF) algorithm to estimate the spatial region between a Cloud of Things (CoT) gateway and an Internet of Things (IoT) device. The accuracy of the spatial region estimation is important for autonomous CoT clustering. We conduct spatial region estimation using a hidden Markov model (HMM) with a raw Bluetooth received signal strength indicator (RSSI). However, the accuracy of the region estimation using the validation data is only 53.8%. To increase the accuracy of the spatial region estimation, the HDF algorithm removes the high-frequency signals hierarchically, and alters the parameters according to whether the IoT device moves. The accuracy of spatial region estimation using a raw RSSI, Kalman filter, and HDF are compared to evaluate the effectiveness of the HDF algorithm. The success rate and root mean square error (RMSE) of all regions are 0.538, 0.622, and 0.75, and 0.997, 0.812, and 0.5 when raw RSSI, a Kalman filter, and HDF are used, respectively. The HDF algorithm attains the best results in terms of the success rate and RMSE of spatial region estimation using HMM.

• 설비공학논문집
• /
• 제23권8호
• /
• pp.549-555
• /
• 2011

For a $CO_2$ one-stage twin rotary compressor, a T-shaped suction port was used to effectively supply the suction gas stream into two individual suction chambers of the twin cylinders. Suction gas pulsations were observed in the pressure sensor signals and these were simulated by using the acoustic modeling of Helmholz resonators in parallel. The module of acoustic modeling was combined to a computer simulation program for the compressor performance. Validation of the simulation program has been carried out for a bench model compressor in a compressor calorimeter. Cooling capacity and the compressor input power were reasonably well compared between the simulation and the calorimeter test. Particularly, good agreement on P-V diagram between the simulation and the test was obtained.

• 대한화장품학회지
• /
• 제40권1호
• /
• pp.37-44
• /
• 2014

화장품에 사용되는 방부제로는 가격이 저렴하고 방부효과가 좋은 파라벤류, 페녹시에탄올 및 클로로페네신 등이 일반적으로 사용된다. 하지만, 최근들어 이들 방부제가 독성과 피부 자극을 유발할 수 있다는 소비자들의 인식으로 인하여 항균 작용이 있는 직쇄상 1,2-알칸디올로 대체되고 있는 추세이다. 하지만, 항균 작용의 직쇄상 1,2-알칸디올도 피부에 자극을 줄 수 있어 제한적으로 사용되어야 하므로 화장품 내 함량을 관리하는 것이 중요하다. 본 실험에서는 가스크로마토그래피 불꽃이온화검출기(GC/FID)를 이용하여 화장품에서 3종의 직쇄상 1,2-알칸디올류 중, 1,2-pentanediol, 1,2-hexanediol, 1,2-octanediol을 동시 분석하였다. 분석법 Validation 결과 특이성을 확인할 수 있었고, 3종의 직쇄상 1,2-pentanediol, 1,2-hexanediol, 1,2-octanediol의 검량선은 $100{\sim}1,200{\mu}g/g$의 농도 범위에서 상관계수가 0.999 이상의 양호한 직선성을 나타내었다. 검출한계(LOD)와 정량한계(LOQ)는 각각 31, 40, $19{\mu}g/g$와 98, 108, $57{\mu}g/g$로 나타났다. 화장품 내 함량에 대한 정밀성(반복성)은 2.0% 이하의 상대표준편차(% RSD)를 나타냈고, 정확성(회수율)은 99.3 ~ 103.3%, 99.4 ~ 106.7%, 97.5 ~ 107.3%로 각각 나타났다. 따라서 화장품 내에서 3종의 1,2-알칸디올류의 동시 분석이 가능함을 알 수 있었다. 본 시험법은 3종의 1,2-알칸디올류를 화장품에서 정확하게 정량하는데 활용될 수 있을 것이다.

• 수면정신생리
• /
• 제30권1호
• /
• pp.22-27
• /
• 2023

목 적: 본 연구에서는 불면증상 뿐만 아니라 과다수면, 하지불안증후군을 포함하여 수면 문제를 포괄적으로 평가하기 위한 수면 문제 선별 설문지(Sleep Problem Screening Questionnaire, SPSQ)를 개발하고, 신뢰도와 타당도를 검증하고자 하였다. 방 법: 불면증상(SPSQi), 과다수면(SPSQh), 하지불안증후군(SPSQr)의 세 가지 하위 영역을 포함하는 SPSQ를 개발하였다. 다음으로, 불면장애 임상군 222명 및 건강군 78명을 대상으로 SPSQ와 비교 척도인 불면증 심각도 척도(Korean version of Insomnia Severity Index)를 진행하고, 해당 데이터를 분석에 사용하였다. 결 과: SPSQ는 수용할만한 내적 일관성과 수렴·변별 타당도를 보여 수면장애의 측정에 타당한 도구로 평가되었다. ROC curve 분석 결과, 불면장애의 임상적 유의미성 판단을 위한 절단점은 SPSQi 6점, 민감도와 특이도는 각각 0.94, 0.96이었다. 결 론: 해당 연구결과는 SPSQ가 일반 성인 인구의 수면 문제를 선별하는데 있어 신뢰할 수 있고 유효한 도구임을 시사한다. 단, 하지불안증후군 및 과다수면 관련 척도와 비교 검증이 수행되지 못한 점을 고려해야겠다.

• 한국연소학회지
• /
• 제18권1호
• /
• pp.7-12
• /
• 2013

A quasidimensional program is developed for a four stroke cycle homogeneous GDI (Gasoline Direct Injection) engine. It includes models for spray, burning rate and chemistry to predict knock and emissions. With early injection a homogeneous GDI engine goes through spark ignited, turbulent premixed combustion as in PFI (Port Fuel Injection) engines. The cylinder charge is divided into unburned and burned zone with the latter divided into multiple zones of equal mass to resolve temperature stratification. Validation is performed against measured pressure traces, NOx and CO emissions at different load and RPM conditions. Comparison is made between an empirical knock model and predictions by the chemistry model in this work.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
• /
• pp.75-82
• /
• 2004

The conditional moment closure(CMC) model has been implemented in context with the unstructured-grid finite-volume method which efficiently handle the physically and geometrically complex turbulent reacting flows. The validation cases include a turbulent nonpremixed $CO/H_2/N_2$ Jet flame and a turbulent nonpremixed $H_2/CO$ flame stabilized on an axisymmetric bluff-body burner. In terms of mean flame field, minor species and NO formation, numerical results has the overall agreement with expermental data. The detailed discussion has been made for the turbulence-chemistry interaction and NOx formation characteristics as well as the comparative performance for CMC and flamelet model.

• Genomics & Informatics
• /
• 제5권1호
• /
• pp.30-31
• /
• 2007

Many visualization tools have been designed to aid information processing during whole genome projects. We have developed a trace viewer program, ChroView, which can read a chromatogram file and display the chromatogram traces of the four bases. The program can be used to examine sequencing quality and base-calling errors. It can also help researchers to edit and save base-calling results while browsing the traces. Additionally, this program has a basecalling feature which can produce supplementary data for validation of the results from other base-calling programs.