• Title/Summary/Keyword: POSTECH

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Development and Validation of a Scale to Measure Engineering Empathy (공학적 공감능력 검사도구 개발 및 타당화 연구)

  • Choi, Sung-Youn;Ma, Eunjeong
    • Journal of Engineering Education Research
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    • v.23 no.5
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    • pp.51-60
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    • 2020
  • The purpose of this study is to develop and validate an Engineering Empathy Instrument. Engineering empathy is defined as the ability that encompasses the following three qualities, a skill to interpret social issues and phenomenon that may occur in the process of interactions between human beings and engineering systems, a practical orientation that enables one to take stakeholders' perspectives to carry out an engineering project, and a professional way of being that acknowledges empathic skills and associated practice orientations. Based on this notion, we develop a scale to measure engineering empathy and have surveyed 429 engineering students. Evidence for the validity and reliability of the scale is presented. In conclusion, we find that engineering empathy can be measured and conceptualized as three domains: a Learnable Skill (ELS), a Practical Orientation (EPO), and a Professional Way (EPW). We also find that sophomores show the highest level of engineering empathy as compared with other graders. While students accumulate technical knowledge, their understanding about engineering in social and interpretational contexts gets weakened. This implies that engineering education necessarily emphasizes the impacts of engineering solutions in interpersonal, societal, technologies, and environmental contexts.

Korean Transition-based Dependency Parsing with Recurrent Neural Network (순환 신경망을 이용한 전이 기반 한국어 의존 구문 분석)

  • Li, Jianri;Lee, Jong-Hyeok
    • KIISE Transactions on Computing Practices
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    • v.21 no.8
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    • pp.567-571
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    • 2015
  • Transition-based dependency parsing requires much time and efforts to design and select features from a very large number of possible combinations. Recent studies have successfully applied Multi-Layer Perceptrons (MLP) to find solutions to this problem and to reduce the data sparseness. However, most of these methods have adopted greedy search and can only consider a limited amount of information from the context window. In this study, we use a Recurrent Neural Network to handle long dependencies between sub dependency trees of current state and current transition action. The results indicate that our method provided a higher accuracy (UAS) than an MLP based model.

A Full Duplex MAC Protocol of Asymmetric Traffic Environment (비대칭 트래픽 환경에서의 전이중 MAC 프로토콜)

  • Ahn, Hyeongtae;Kim, Cheeha
    • KIISE Transactions on Computing Practices
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    • v.22 no.8
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    • pp.381-386
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    • 2016
  • Recently full-duplex communication in wireless networks is enabled by the advancement of self-interference cancellation technology. Full-duplex radio is a promising technology for next-generation wireless local area networks (WLAN) because it can simultaneously transmit and receive signals within the same frequency band. Since legacy medium access control (MAC) protocols are designed based on half-duplex communication, they are not suitable for full-duplex communication. In this paper, we discuss considerations of full-duplex communication and propose a novel full-duplex MAC protocol. We conducted a simulation to measure the throughput of our MAC protocol. Through the simulation results, we can verify that significant throughput gains of the proposed full-duplex MAC protocol, thus comparing the basic full-duplex MAC protocol.

Quantitative Analysis on the Effects of Welding Parameters on Diffusible Hydrogen Contents in Weld Metal Produced by FCAW Process (FCAW에서 용접금속 확산성수소량에 미치는 용접변수 영향의 정량적 해석)

  • Han, Dong-Woo;Bang, Kook-Soo;Jeong, Hong-Chul;Lee, Jong-Bong
    • Journal of Welding and Joining
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    • v.28 no.2
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    • pp.54-59
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    • 2010
  • The effects of welding parameters such as contact tip-to-work distance (CTWD), voltage, and current on the weld metal diffusible hydrogen contents (HD) were investigated and rationalized by the calculation of heating time and amount of heat generated in the extension length of flux cored wire. As CTWD increased from 15 to 25mm, HD decreased from 8.46 to 5.45mL/100g deposited metal. Calculations showed that, with an increase of CTWD, the amount of heat generated increased from 46 to 92J in addition to an increase of heating time. Increase of current from 250 to 320A, however, gave little variation of HD. It showed that no significant change in the amount of heat generated was found, and heating time was decreased with an increase of current. It also showed that CTWD is more influential than voltage in relatively lower heat input ranges, while voltage is more in higher input ranges

A Study on Socio-cultural Functions of Game-Making Events (게임개발대회의 사회문화적 기능에 대한 연구)

  • Ma, Eunjeong;Choi, Sung-Youn
    • Journal of Korea Game Society
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    • v.19 no.5
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    • pp.77-90
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    • 2019
  • This paper discusses the shaping of game culture and the socio-cultural functions of game-making events based on co-production ideation by meta-analysis. Research has shown that the experience in this event helps to reshape the perception of the game culture, which eventually will lead to the extended meanings of game culture. It can also be seen that the game-making event serves as an educational platform for building the next generation competencies.

Study on Seabed Mapping using Two Sonar Devices for AUV Application (복수의 수중 소나를 활용한 수중 로봇의 3차원 지형 맵핑에 관한 연구)

  • Joe, Hangil;Yu, Son-Cheol
    • The Journal of Korea Robotics Society
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    • v.16 no.2
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    • pp.94-102
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    • 2021
  • This study addresses a method for 3D reconstruction using acoustic data with heterogeneous sonar devices: Forward-Looking Multibeam Sonar (FLMS) and Profiling Sonar (PS). The challenges in sonar image processing are perceptual ambiguity, the loss of elevation information, and low signal to noise ratio, which are caused by the ranging and intensity-based image generation mechanism of sonars. The conventional approaches utilize additional constraints such as Lambertian reflection and redundant data at various positions, but they are vulnerable to environmental conditions. Our approach is to use two sonars that have a complementary data type. Typically, the sonars provide reliable information in the horizontal but, the loss of elevation information degrades the quality of data in the vertical. To overcome the characteristic of sonar devices, we adopt the crossed installation in such a way that the PS is laid down on its side and mounted on the top of FLMS. From the installation, FLMS scans horizontal information and PS obtains a vertical profile of the front area of AUV. For the fusion of the two sonar data, we propose the probabilistic approach. A likelihood map using geometric constraints between two sonar devices is built and a monte-carlo experiment using a derived model is conducted to extract 3D points. To verify the proposed method, we conducted a simulation and field test. As a result, a consistent seabed map was obtained. This method can be utilized for 3D seabed mapping with an AUV.

INSTABILITY OF THE BETTI SEQUENCE FOR PERSISTENT HOMOLOGY AND A STABILIZED VERSION OF THE BETTI SEQUENCE

  • JOHNSON, MEGAN;JUNG, JAE-HUN
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.25 no.4
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    • pp.296-311
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    • 2021
  • Topological Data Analysis (TDA), a relatively new field of data analysis, has proved very useful in a variety of applications. The main persistence tool from TDA is persistent homology in which data structure is examined at many scales. Representations of persistent homology include persistence barcodes and persistence diagrams, both of which are not straightforward to reconcile with traditional machine learning algorithms as they are sets of intervals or multisets. The problem of faithfully representing barcodes and persistent diagrams has been pursued along two main avenues: kernel methods and vectorizations. One vectorization is the Betti sequence, or Betti curve, derived from the persistence barcode. While the Betti sequence has been used in classification problems in various applications, to our knowledge, the stability of the sequence has never before been discussed. In this paper we show that the Betti sequence is unstable under the 1-Wasserstein metric with regards to small perturbations in the barcode from which it is calculated. In addition, we propose a novel stabilized version of the Betti sequence based on the Gaussian smoothing seen in the Stable Persistence Bag of Words for persistent homology. We then introduce the normalized cumulative Betti sequence and provide numerical examples that support the main statement of the paper.

A Brief Review of κ-Carbide in Fe-Mn-Al-C Model Alloys

  • Seol, Jae Bok
    • Applied Microscopy
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    • v.48 no.4
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    • pp.117-121
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    • 2018
  • The multiple length scale analysis of previously designed Fe-Mn-Al-C based low-density model alloys reveals the difference in ordered ${\kappa}-carbide$, $(Fe,Mn)_3AlC_x$, between Fe-25Mn-16Al-5.2C (at%) alloy and Fe-3Mn-10Al-1.2C (at%) alloy. For the former alloy composition consisting of fully austenite grains, ${\kappa}-carbide$ showed majorly cuboidal and minorly pancake morphology and its chemical composition was not changed through aging for 24 h and 168 h at $600^{\circ}C$. Meanwhile, for the isothermally annealed ferritic alloy system for 1 hr at 500 and $600^{\circ}C$, the dramatic change in the chemical composition of needle-shape ${\kappa}-carbide$, $(Fe,Mn)_3(Fe,Al)C_x$, was found. Here we address that the compositional fluctuations in the vicinity of the carbides are significantly controlled by abutting phase, either austenite or ferrite. Namely, the cooperative ordering of carbon and Al is an important factor contributing to carbide formation in the high-Mn and high-Al alloyed austenitic steel, while the carbon and Mn for the low-Mn and high Al alloyed ferritic steel.

Suppression of Melanose Caused by Diaporthe citri on Citrus Leaves Pretreated with Bio-sulfur

  • Shin, Yong Ho;Ko, Eun Ju;Kim, Su Jeong;Hyun, He Nam;Jeun, Yong Chull
    • The Plant Pathology Journal
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    • v.35 no.5
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    • pp.417-424
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    • 2019
  • Melanose, caused by Diaporthe citri, is one of severe diseases in citrus, a major economic resource in Jeju island. To reduce the usage amount of organic synthetic fungicide, bio-sulfur was tested as an alternative chemical to control citrus melanose in the present study. Direct antifungal activity of bio-sulfur against D. citri was determined through in vitro experiment using artificial nutrient media. Disease severity of melanose on bio-sulfur pretreated citrus leaves was lower than that on untreated ones. To illustrate the mechanism of disease suppression by bio-sulfur, infection structures were observed with a fluorescent microscope and a scanning electron microscope. In fluorescent microscopic observation, most conidia rarely germinated. In addition, hyphal growth on leaves pretreated with bio-sulfur was inhibited compared to that on untreated ones. In scanning electron microscope images of bio-sulfur pretreated leaves, surfaces of most conidia were shrunk while hyphae were morphologically changed and frequently branched. Such microscopic observations were also found for leaves pretreated with a commercial fungicide Dithianon. These results suggest that bio-sulfur may be used to control citrus melanose as an environment friendly alternative to organic synthetic fungicides