Examining the sructure of a writing assessment using confirmatory factor analysis

( Taejoon Park ) 한국중등영어교육학회 2015 중등영어교육 Vol.8 No.2

The purpose of this study was twofold: (a) to examine the factorial structure of a writing assessment administered to a group of English learners, and (b) to examine the extent to which the test takers`` performance on the writing assessment is affected by the underlying traits (i.e., the aspects of writing ability being tabbed into by the analytic rating scales) and the test methods (e.g., writing tasks and raters) being used to elicit and score test performance. A series of confirmatory factor analysis (CFA) models were tested for the purpose of seeking the best representation of the underlying trait and method factor structure for the measurement design of the writing assessment. The examination of the factor loadings of the final CFA model revealed that the method factor loadings associated with writing tasks were higher than the trait factor loadings for all but one of the observed variables, indicating the impact of strong task effects on the test takers`` performance on the writing assessment. The implications of the results are discussed in terms of the role of tasks in writing performance assessments.

The flexible routing with flex for the fast delivery

TaeJoon Park(박태준),Yerim Chung(정예림) 한국컴퓨터정보학회 2021 韓國컴퓨터情報學會論文誌 Vol.26 No.9

본 논문의 목적은 빠른 배송을 위한 배송 차량의 유연 회차와 크라우드쉬핑(Crowd Shipping) 배달원인 플렉스를 활용한 “유연 회차와 플렉스” 방식을 제안하고, 풀이 알고리즘을 제안하는 것이다. 알고리즘은 선행 연구에서 성능이 검증된 2-opt를 사용하여 차량 경로를 계산하고, 절약 휴리스틱(Saving heuristic)을 변형한 방식으로 플렉스에 할당할 고객을 계산한다. 알고리즘은 차량과 플렉스를 분리하는 것이 아니라, 상호 보완적으로 운용될 수 있게 한다. 이를 위해 차량 정보가 플렉스 할당 과정에 고려되도록 하였다. 본 연구의 실험은 다양한 도심지의 상황을 상정한 Random, Mixed, Cluster 인스턴스로 구성되었다. 실험 결과 모든 인스턴스에서는 플렉스의 사용이 차량 유연 회차의 효율성을 높여주는 것을 확인하였다. 또 플렉스와 배송 지연 시간 비용에 대한 민감도분석에서는 “유연 회차와 플렉스”가 차량만을 사용하는 방식의 차량 대수에 따라 값에 차이를 보였지만, 플렉스 비용이나 배송 지연 시간 비용이 200% 증가하는 경우에도 우위를 유지하는 것을 확인하였다. 본 연구의 결과는 플렉스가 차량과 연계되어 활용되는 경우, 플렉스에 의해 서비스되는 고객뿐만 아니라 차량으로 서비스되는 고객들의 서비스 품질을 높일 수 있음을 보여준다. In this paper, we propose “flexible routing with flex” to provide fast delivery by using the flexible routing for the delivery vehicle and crowd-shipper named flex. To this end, we have introduced an algorithm that can build the delivery plan for delivery vehicles and flexes. The introduced algorithm uses the 2-opt algorithm to construct routes with low complexity and acceptable quality, and the revised saving algorithm to assign customer orders to the flex. The algorithm allows the vehicle and the flex to function complement each other without separating the delivery vehicle from the flex. The experiments consider the 3 different instances named Random, Mixed, Cluster, and show that “the flexible routing with flex” has a better result than “vehicle only”. The sensitivity analysis of the flex cost and time penalty shows “the flexible routing with flex” can provide better service not only to the customers who are serviced by flex but also to the customers who are serviced by the delivery vehicle.

Development of IoT based Real-Time Complex Sensor Board for Managing Air Quality in Buildings

Park, Taejoon,Cha, Jaesang The Institute of Internet 2018 International Journal of Internet, Broadcasting an Vol.10 No.4

Efforts to reduce damages from micro dust and harmful gases in life have been led by national or local governments, and information on air quality has been provided along with real-time weather forecast through TV and internet. It is not enough to provide information on the individual indoor space consumed. So in this paper, we propose a IoT-based Real-Time Air Quality Sensing Board Corresponding Fine Particle for Air Quality Management in Buildings. Proposed board is easy to install and can be placed in the right place. In the proposed board, the air quality (level of pollution level) in the indoor space (inside the building) is easy and it is possible to recognize the changed indoor air pollution situation and provide countermeasures. According to the advantages of proposed system, it is possible to provide useful information by linking information about the overall indoor space where at least one representative point is located. In this paper, we compare the performance of the proposed board with the existing air quality measurement equipment.

An Investigation into the Variability of a Writing Test Using Generalizability Theory

Taejoon Park(박태준) 한국외국어교육학회 2008 Foreign languages education Vol.15 No.1

Because performance assessment such as a composition test introduces a range of factors that may influence the chances of success for a candidate on the test, those in charge of monitoring quality control for performance assessment programs need to gather information that will help them determine whether all aspects of the programs are working as intended. In the present study, generalizability theory (Brennan, 1992) was employed to examine the relative effects of various sources of variability on students" performance on an essay writing test and also to investigate the reliability of the assigned scores. The results showed that due to the largest effect associated with the students" writing ability and negligible effects associated with facets of measurement such as scoring criteria and ratings, the generalizability coefficient estimated for the writing test was high, suggesting that the test is a reliable measure of what it purports to measure, the students" writing ability.

A study on BEMS-linked Indoor Air Quality Monitoring Server using Industrial IoT

Taejoon Park,Jaesang Cha 한국인터넷방송통신학회 2018 International Journal of Internet, Broadcasting an Vol.10 No.4

In this paper, we propose an interworking architecture for building indoor air quality monitoring server (BEMS) using IIoT (Industrial Internet of Things). The proposed monitoring server adopts IIoT-based standard protocol so that interaction with BEMS installed in existing buildings can be performed easily. It can effectively communicate with indoor air quality measurement sensor installed in the building based on IIoT, Indoor air quality monitoring is possible. We implemented a proposed monitoring server, and confirmed the availability and monitoring of data from sensors in the building.

A study on BEMS-linked Indoor Air Quality Monitoring Server using Industrial IoT

Park, Taejoon,Cha, Jaesang The Institute of Internet 2018 International Journal of Internet, Broadcasting an Vol.10 No.4

In this paper, we propose an interworking architecture for building indoor air quality monitoring server (BEMS) using IIoT (Industrial Internet of Things). The proposed monitoring server adopts IIoT-based standard protocol so that interaction with BEMS installed in existing buildings can be performed easily. It can effectively communicate with indoor air quality measurement sensor installed in the building based on IIoT, Indoor air quality monitoring is possible. We implemented a proposed monitoring server, and confirmed the availability and monitoring of data from sensors in the building.

Development of IoT based Real-Time Complex Sensor Board for Managing Air Quality in Buildings

Taejoon Park,Jaesang Cha 한국인터넷방송통신학회 2018 International Journal of Internet, Broadcasting an Vol.10 No.4

Efforts to reduce damages from micro dust and harmful gases in life have been led by national or local governments, and information on air quality has been provided along with real-time weather forecast through TV and internet. It is not enough to provide information on the individual indoor space consumed. So in this paper, we propose a IoT-based Real-Time Air Quality Sensing Board Corresponding Fine Particle for Air Quality Management in Buildings. Proposed board is easy to install and can be placed in the right place. In the proposed board, the air quality (level of pollution level) in the indoor space (inside the building) is easy and it is possible to recognize the changed indoor air pollution situation and provide countermeasures. According to the advantages of proposed system, it is possible to provide useful information by linking information about the overall indoor space where at least one representative point is located. In this paper, we compare the performance of the proposed board with the existing air quality measurement equipment.

Numerical Simulation of Time-dependent Spring-back Behavior for Aluminum Alloy 6022-T4 Sheet

Taejoon Park,Kwansoo Chung,Hansun Ryou,Myoung-Gyu Lee,R.H. Wagoner 한국소성가공학회 2010 기타자료 Vol.2010 No.6

In order to analyze the time-dependent spring-back behavior of the aluminum alloy 6022-T4 sheet, the viscoelastic/plastic constitutive law was applied by utilizing a linear viscoelastic/plastic model previously developed. As for the plastic deformation, the combined isotropic-kinematic hardening law was used to represent the Bauschinger behavior and transient hardening, while a non-quadratic anisotropic yield function, Yld2000-2d, was applied to account for anisotropic yield behavior. The numerical formulation was developed based on the incremental deformation viscoelastic/plasticity theory and then, the constitutive law was implemented into the ABAQUS/Standard commercial finite element program using the user-defined material subroutine, UMAT. The viscoelastic behavior was characterized by the creep test above the initial yield stress level, while anisotropic yielding and hardening parameters were obtained by the uniaxial tensile test. The constitutive law and the formulation were successfully validated for time-dependent springback in the draw-bend test.

Practical applications of solid-state NMR in industry

Taejoon Park 한국분석과학회 2021 학술대회논문집 Vol.2021 No.5

A Modified TCP Congestion Avoidance Mechanism for Networks with Large Bandwidth Delay Product

TaeJoon Park,SeongSoon Joo,JaeYong Lee,ByungChul Kim 대한전자공학회 2005 ITC-CSCC :International Technical Conference on Ci Vol.2005 No.4