• 한국수학교육학회지시리즈C:초등수학교육
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• 제24권4호
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• pp.203-216
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• 2021

이 연구의 목적은 초등학교 수학교실에서 시행되는 경과시간 수업에서 학생들에게 제공되는 수학 학습기회를 탐색하는 것이다. 경과시간을 도입하는 데에 있어 후속 학년과의 수학적 연결성을 갖도록 경과시간을 양적으로 대상화하려는 교사들의 노력을 문서화하고자 하였다. 이를 위해 세 초등교사의 경과시간 도입 수업을 관찰하고 내러티브 분석을 시행하였다. 그 결과, 교사들은 도구를 사용하여 학생들이 경과시간을 양적으로 접근할 수 있도록 지원하고 있었으며, 같은 도구라도 서로 다른 양적 측면을 강조하였다. 아날로그 시계의 경우 한 교사는 시계바늘의 회전 바퀴 수로 양적 대상화를 시도한 반면, 다른 교사는 시계바늘이 아동한 거리로 경과시간의 양을 표상하였다. 시간띠의 길이 속성으로 경과시간의 양을 표상하는 경우도 있었다. 결과를 바탕으로 경과시간의 수업에서 다양하게 포착된 양적 대상화 사례들의 교수학적 의미를 논의하였다.

• 한국수학교육학회지시리즈A:수학교육
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• 제60권3호
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• pp.249-264
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• 2021

이 연구는 사회문화적인 관점에서 경과시간이라는 수학적 대상을 구현하는 기표를 통해 학생들의 경과시간 이해를 탐색하였다. 연구 결과, 학생들은 주어진 기표에 따라 차별화된 방식으로 경과시간 과제를 수행하고 있음이 확인되었고, 개별적으로 구성된 학생들의 경과시간 구현 기표 수형도는 이들이 특히 아날로그 시계 기표에서 경험하는 차별화된 과제 수행을 설명해주었다.

• 대한한의학방제학회지
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• 제20권1호
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• pp.133-147
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• 2012

Objectives : This study was intended to understand characteristics of symptoms, oriental medicine prescription and laboratory test results according to elapsed time of stroke. Methods : Through the medical records of 205 stroke inpatients in the oriental medical hospital in the year 2010, we investigated manifested symptoms, administered oriental medicine prescription and clinical pathological examination results. Collected items were classified to depend on stroke types, cerebral infarction and hemorrhage. We analyzed association between manifested symptoms, the oriental medicine prescription, and laboratory test results of stroke patients and elapsed time. Chi-square tests were performed to determine the significance level of association. Results : All symptoms, prescriptions and laboratory test results in cerebral infarction patients were associated with elapsed time. Especially, symptoms, prescriptions and pathological examination results showed very high statistical significance with elapsed time (a symptom; chi-square(df)=164.3(22), p<0.001, prescription; chi-square(df)=93.5(22), p<0.001, and pathological examination results; chi-square(df)=164.3(22), p<0.0004). But in the case of cerebral hemorrhage, there was not statistical significance. Conclusions : The elapsed time of stroke may be an essential requisite in catching symptoms and prescribing for stroke patients in oriental medical treatment.

• 한국표면공학회지
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• 제50권5호
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• pp.405-410
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• 2017

In order to study current-voltage-luminance and impedance characteristics according to elapsed time, a blue fluorescent OLED was fabricated. The current density and luminance gradually decreased in accordance with elapsed time and did not emit light after 480 hours, and the threshold voltage increased as time elapsed. The Cole-Cole plot was a semicircular shape of a very large size at 2 V of the applied voltage below the threshold voltage, and the maximum value of the real number impedance did not change greatly from 9314.5 to $9902.2{\Omega}$ as time elapsed. Applied voltages 4, 6, and 8 V above the threshold voltage showed a large change in the real number impedance value at the semicircle end to 9,678.2, 9,826, $9,535.4{\Omega}$ according to the elapsed time from 2,222.5, 183.7, $48.2{\Omega}$ immediately after fabricating the device. By increasing the applied voltage beyond the threshold voltage just after device fabrication, the energy difference between the device and the organic layer was overcome and the current flowed, the maximum value of the real number impedance sharply decreased. As time passed, current did not flow through the element even at high applied voltage due to degradation of the element, and even when the applied voltage was higher than the threshold voltage, it showed an impedance value such as applied voltage equal to or less than the threshold voltage. As a result, it can be learned that the change in the impedance with elapsed time reflects the characteristics due to the degradation of the OLED and can predict the characteristics and lifetime of the OLED.

• 대한가정학회지
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• 제48권6호
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• pp.83-101
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• 2010

Using the first wave of KLoSA(Korean Longitudinal study of Aging) beta version, this study analyzed factors affecting retirement adjustment by elapsed time from retiree's retirement through Binary Logit and Multinomial Logit Analysis. Participants were 1,780 retiree. The main results of this study were as follows : First, The retiree's education(-), health status(-), region(+), dwelling type(-), monthly household income(-), employment type before retirement(+), retirement reason(+), and the elapsed time from retirement(-) were affected whether they satisfied with pre-retirement or not. Second, The gender(-), age(-), and the region(+) were affected whether they satisfied with life after retirement or not. Third, The gender(-), age(-), education(+), heath status(+), dwelling type(+), monthly household income(+), retirement reason(-), and the elapsed time from retirement(+) were affected on their satisfaction after retirement compared to pre-retirement. Last, The different factors affected the life satisfaction after retirement by elapsed time from retirement.

• 한국생산제조학회지
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• 제20권2호
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• pp.157-161
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• 2011

The study for traffic safety improvement is so necessary to minimize the wound of pedestrian at car impact as to prevent pedestrian from this accident. This study aims at analyzing the behavior affected by impact on which car body hits pedestrian. Load and damage of pedestrian are also investigated. This model is the small car body as frame structure. The pedestrian is modeled with dummy by CATIA as Korean standard body style. The ear impacts the side of pedestrian with the speed from 30 to 90km/h. Behavior and damage of pedestrian at impact are analyzed by ANSYS. In case of 30km/h, The maximum pressure of dummy becomes the maximum value of 100MPa after the elapsed time of 0.1second and then seems to remain at 105MPa constantly. In case of 60km/h, its pressure becomes the maximum value of 110MPa at the elapsed time of 0.05second and decreases at 90MPa until the elapsed time of 0.1second. This value fluctuates after the elapsed time of 0.1second. In case of 90km/h, its maximum pressure becomes the maximum value of 155MPa at the elapsed time of 0.07second and fluctuates after the elapsed time of 0.07second until O.3second. This value seems to remain at 100MPa constantly after 0.3second until 0.5second. But this pressure increases suddenly just after 0.5second. Maximum deformations of dummy increase linearly according to elapsed time at hitting velocities of 30, 60 and 90km/h.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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• pp.487-492
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• 1999

The purpose of this study to find the mixture of concrete for Top-Down method. Throughout test of elapsed time change and L-type flow, it was proposed basic performance and level of top-down method concrete. When change as to elapsed time is considered, so series of F10 added 10% S.P satisfied slump and demanded flow (60$\pm$5cm), and L-type slump, L-type flow satisfied liquidity, it can be considered basic mixture of designed actual frame later.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.53-54
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• 2022

This study is a basic study to establish the relationship between the conventional fluidity evaluation data of concrete and the rheology parameters. the slump flow and rheology parameters were measured according to the elapsed time after the concrete was mixed. The correlation between the slump flow and the rheology constant was analyzed and the effect of the elapsed time after concrete beating on the correlation between the two data was analyzed.

• Journal of Astronomy and Space Sciences
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• 제25권4호
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• pp.481-490
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• 2008

반작용휠은 인공위성의 기동 및 자세제어에 사용되는 주요 구동기 중의 하나로 회전체의 속도를 변화시켜 발생하는 토크로 위성의 자세제어를 수행하므로 정밀한 자세제어를 위해서는 정확한 회전속도의 측정이 요구된다. 타코 펄스를 이용한 고속 회전모터의 대표적인 속도 측정방법에는 Elapsed-time측정방법과 Pulse-count측정방법의 두 가지가 있으며 이 연구에서는 반작용휠의 속도 측정을 하는 동안 발생할 수 있는 속도 측정의 오차 및 정밀도를 두 가지 방법에 대해 분석, 비교하였다. 그 결과 Pulse-count측정방법은 반작용휠의 등속 구동 시 회전속도에 상관없는 일정한 오차를 가지는데 비해 Elapsed-time측정방법은 회전속도가 작을수록 오차가 줄어드나 저속일 때 오차가 현저히 커질 수 있음을 해석적으로 확인하였다.

• 한국컴퓨터정보학회논문지
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• 제21권5호
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• pp.1-10
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• 2016

Magnetic disks have been used for decades in auxiliary storage devices of computer systems. In recent years, the use of NAND flash memory, which is called SSD, is increased as auxiliary storage devices. However, NAND flash memory, unlike traditional magnetic disks, necessarily performs the erase operation before the write operation in order to overwrite data and this leads to degrade the system lifetime and performance of overall NAND flash memory system. Moreover, NAND flash memory has the lower endurance, compared to traditional magnetic disks. To overcome this problem, this paper proposes EPET (Enhanced Prediction and Elapsed Time) wear leveling technique, which is especially efficient to portable devices. EPET wear leveling uses the advantage of PET (Prediction of Elapsed Time) wear leveling and solves long-term system failure time problem. Moreover, EPET wear leveling further improves space efficiency. In our experiments, EPET wear leveling prolonged the first bad time up to 328.9% and prolonged the system lifetime up to 305.9%, compared to other techniques.