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Accuracy order of grammatical morphemes of Korean EFL learners: Disparities among the same L1 groups
Young Seog,Daria Soon 경희대학교 언어연구소 2015 언어연구 Vol.32 No.S
Studies questioning the proposed invariant natural order of second language (L2) morpheme acquisition have reported evidence of strong first language (L1) effects on the acquisition order of L2 English grammatical morphemes. In view of these findings, the current study investigated disparities in the morpheme acquisition orders of different groups with the same L1 Korean background. First, this study examined 173 writing samples written by Korean elementary school students learning English as a foreign language (EFL) to investigate the acquisition order of eight grammatical morphemes. Afterwards, the revealed order was compared to the findings from previous studies conducted with L1 Korean groups. The results showed that the acquisition order of the Korean EFL learners of this study did not support the natural order. Furthermore, comparison of findings to previous studies revealed disparities among the L1 Korean groups learning English indicating the need for investigation into methodology as well as other external determinants in addition to L1 transfer. (Kyungpook National University)
A Cohesive Surface Separation Potential
Youngseog Lee,Kwang Soo Kim 대한기계학회 2002 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.16 No.11
This paper presents a form of the cohesive surface separation potential, which can produce potential curves by varying a single dimensionless parameter. Results show that a partial modification of Xu and Needleman's (1994) cohesive surface separation potential makes it possible to present the other potential curves as a special case as long as the normal separation is concerned. The proposed potential may describe interfacial debonding-crack initiation and growth-character of materials and, through numerical simulation, provide an insight for the effect of different cohesive surface separation potentials on the interfacial debonding.<br/>
Constitutive Relation of Alloy Steels at High Temperatures
Youngseog Lee 한국정밀공학회 2005 International Journal of Precision Engineering and Vol.6 No.4
This paper presents a feasibility study whether Shida's constitutive equation being widely used for plain carbon steel in steel manufacturing industry can be extended to alloy steels with a due carbon equivalent model. The constitutive relation of the alloy steels (SAE9254, AISI52l00 and AISI4140) is measured using hot deformation simulator (GLEEBLE 3500C) at high temperatures (800℃~1000℃) within strain rates of 0.05~40s?¹. It has been found the predicted flow stress behavior (constitutive relation) of AISI52100 steel is in agreement with the measured one. On the other hand, the measured flow stress behavior of SAE9254 and AISI4140 steel partly concords with the predicted one when material experiences relatively high strain rate (10~40s?¹) deformation at low temperature (800℃). It can be deduced that, for AISI52100 steel, Shida's equation with the carbon equivalent model can be applicable directly to the roughing and intermediate finishing stand in hot rolling process for calculating the roll force and torque.
Prediction Model of the Exit Cross Sectional Shape of Workpiece in Round-Oval-Round Pass Rolling
Youngseog Lee,Byung-Min Kim,Dong Hwan Kim 대한기계학회 2002 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.16 No.6
A reliable analytic model that predicts the surface profile of the exit cross section of workpiece in round-oval (or oval-round) pass sequence is established. The presented model does not require any plasticity theory but needs the only geometric information on workpiece and roll groove. Formulation is based on the linear interpolation of the radius of curvature of an incoming workpiece and that of roll groove in the roll axis direction when the maximum spread of workpiece is known beforehand. The validity of the analytic model is examined by hot rod rolling experiment with the roll gap, specimen size, design parameter of oval groove and steel grade changed. Results revealed that the cross sectional shapes predicted by the model were in good agreement with those obtained experimentally. We found that the analytic model not only has simplicity and accuracy for practical usage but also saves a large amount of computational time in comparison with finite element method.
Effect of Rolling Speed on the Exit Cross Sectional Shape in Rod Rolling Process
Youngseog Lee 한국정밀공학회 2007 International Journal of Precision Engineering and Vol.8 No.1
A rolling speed dependent spread model is proposed for predicting the exit cross sectional shape in oval-round (or round-oval) pass rod rolling process when the rolling speed is very high. The effect of rolling speed on the exit cross sectional shape is measured by performing a four-pass continuous high speed (~80㎧) rod rolling test and is described in terms of the spread correction parameter. The validity of the model is examined by applying it to rod rolling process at POSCO No. 3 Rod Mill. The cross sectional shapes of workpiece predicted by the proposed model coupled with the surface profile prediction method? are in good agreement with those obtained experimentally.
Lee, Youngseog,Bayoumi, Laila-Salah,Kim, Hong-Joon The Korean Society of Mechanical Engineers 2002 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.16 No.4
This paper presents a study of the effect of varying the roll gap of oval pass in round-oval-round pass sequence on the interracial slip of workpiece, entrance and exit velocities, stresses and roll load that the workpiece experiences during rolling, by applying analytical method, finite element simulation and verification through hot bar rolling tests. The results have shown that the roll gap variation of oval pass affects the interfacial slip of workpiece along the groove contact and the specific roll pressure. The optimum conditions in terms of minimum interfacial slip and minimum specific roll pressure, which might influence the maximum groove life, is obtained when the subsequent round pass is completely filled.
An Approximate Model for Predicting Roll Force in Rod Rolling
Lee, Youngseog,Kim, Hong-Joon The Korean Society of Mechanical Engineers 2002 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.16 No.4
This paper presents a study of the effect of rolling temperature, roll gap (pass height), initial specimen size and steel grades of specimens on the roll force in round-oval-round pass sequence by applying approximate method and verifications through single stand pilot rod rolling tests. The results show that the predicted roll forces are in good agreement with the experimentally measured ones. The approximate model is independent of the change of roll gap, specimen size and temperature. Thus, the generality of the prediction methodology employed in the approximate model is proven. This study also demonstrates that Shida's constitutive equation employed in the approximate model needs to be corrected somehow to be applicable for the medium and high carbon steels in a lower temperature interval (700∼900$\^{C}$).
A Cohesive Surface Separation Potential
Lee, Youngseog,Kim, Kwang-Soo The Korean Society of Mechanical Engineers 2002 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.16 No.11
This paper presents a form of the cohesive surface separation potential, which can produce potential curves by varying a single dimensionless parameter. Results show that a partial modification of Xu and Needleman's (1994) cohesive surface separation potential makes it possible to present the other potential corves as a special case as long as the normal separation is concerned. The proposed potential may describe interfacial debonding-crack initiation and growth-character of materials and, through numerical simulation, provide an insight for the effect of different cohesive surface separation potentials on the interfacial debonding.
김영석(Youngseog Kim) 경상대학교 사회과학연구원(사회과학연구) 2020 사회과학연구 Vol.36 No.-
Academic credentialism refers to a system that establishes socioeconomic hierarchies based on intellectual achievements. Academic credentialism came into play as a means of justification for the capitalist system because there is a vague assumption that intellectual performance compared through objective means such as examination explains an individual"s overall competencies such as judgment, character, and job performance. However, academic credentialism is a very inefficient system for creating human capital, contrary to what it symbolizes, by evaluating individuals" abilities and achievements in a very limited way. In particular, Korean society, which evaluates everything through tests, always complains of the lack of creative innovation. The economic utility that school education gives to consumers is limited only to students who go to the top of the hierarchical university system, and competition for it is in fact forced to depend on the economic power of parents. Most schools have lost their educational function and are being transformed into institutions that perform only accommodation functions. The overcoming of academic credentialism presupposes a change in the social environment, which comes from the civic awakening that academicism is unfair. It is the time when the awakening is needed to escape from the uniform lineup where the majority of the people are losers.