• 전기의세계
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• v.23 no.4
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• pp.53-59
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• 1974

This paper investigates the theoretical properties of a logic element called the multithreshold threshold element, which is a generalization of the single-threshold threshold element. The primary partition os a systematic method of obtaining the multi-threshold realization of a switching function by the index numbers. The concept of comparable vertices of the same index numbers introduced in this paper is very promising for testing the multi-threshold partition by the initial condition to be defined by the minterms of the same index numbers.

• Journal of Mechanical Science and Technology
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• v.19 no.4
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• pp.985-992
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• 2005

Vehicle Stability Control (VSC) system prevents vehicle from spinning or drifting out mainly by braking intervention. Although a control threshold of conventional VSC is designed by vehicle characteristics and centered on average drivers, it can be a redundancy to expert drivers in critical driving conditions. In this study, a manual adaptation of VSC is investigated by changing the control threshold. A control threshold can be determined by phase plane analysis of side slip angle and angular velocity which is established with various vehicle speeds and steering angles. Since vehicle side slip angle is impossible to be obtained by commercially available sensors, a side slip angle is designed and evaluated with test results. By using the estimated value, phase plane analysis is applied to determine control threshold. To evaluate an effect of control threshold, we applied a 23-DOF vehicle nonlinear model with a vehicle planar motion model based sliding controller. Controller gains are tuned as the control threshold changed. A VSC with various control thresholds makes VSC more flexible with respect to individual driver characteristics.

• Journal of the Korean Chemical Society
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• v.59 no.4
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• pp.308-319
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• 2015

As a follow-up study to identify references for threshold concepts in science, 20 high school chemistry teachers were interviewed. Seven concepts were identified as threshold concepts. The data revealed that teachers overcome the thresholds while they are teaching as well as learning during their school years. This explains that the mastery experience of threshold concepts involve not only the process of creating subject matter knowledge of a learner but also the reflection on or preparation for teaching. Hence, the current study proposes that a strong relationship exists between the mastery experience of threshold concepts and the development of teachers’ pedagogical content knowledge (PCK). In this regard, findings from this study will provide valuable information to understand the nature of threshold concepts and suggests the value of mastery experience of threshold concepts in terms of PCK development.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1998.05a
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• pp.315-320
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• 1998

n명의 사용자들 중 k명 이상이 모이면 시스템의 비밀정보가 재구성 되는 시스템을 threshold cryptosystem 이라고 한다. 1979년 Adi Shamir에 의해 threshold 개념이 제안된 이래로, 그 현실적인 효용성때문에 많은 연구들이 이루어져 왔다. Threshold cryptosystem을 구성하기 위해서는 n명의 사용자들이 각자의 share를 가지고 있어서 그 중 k명 이상이 자신의 share를 밝히면 시스템의 비밀정보가 재구성된다. 그러나, 시스템의 비밀정보가 재구성 된 후에는 각 사용자들의 share를 재분배해야 한다. 이러한 특성은 반복적으로 전자서명과 같은 비밀연산을 수행해야 하는 응용에서는 비현실적이 된다. 이러한 경우에 적용시키기 위한 암호시스템이 threshold signature이다. (t, n)-threshold signature 시스템에서는 n명의 사용자들 중 k명 이상이 자신의 share를 이용한 부분서명을 수행하면 전체 시스템 서명이 생성된다. 그러나, 시스템의 비밀정보는 재구성 되지 않으므로 아무도 알 수 없고, 따라서 재분배 할 필요가 없다. 본 논문에서는 이러한 threshold signature 시스템에 대한 연구결과들을 살펴본다.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.73-77
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• 2010

Purpose: The nuclear medicine technology has been changed. The hard ware is developed so much. Also the soft ware performs a meritorious deed for the development of nuclear medicine technology. We could use the automated region of interest (ROI) instead of manual ROI. We want to know that what difference of quantitative analysis is there between automated ROI and manual ROI Materials and Methods: There are three experimental to make results. The first is what comparing the renal automated ROI and manual ROI. The second is that we compared three threshold ROI that size is difference each others with visible decision. The third is that we compared full, half, quarter automated background, and survey relative function. Results: Although the first has statistically not significant difference, the second and third have significant difference. Threshold, setting smaller threshold then renal outline or bigger, has statistically significant difference (p<0.01). The third is performed with the first experimental. Full background has significant difference, comparing each three type background (p<0.05). Conclusion: The results that there is not significant difference between automated ROI and manual ROI will increase objectivity and operator's convenience. We could know that smaller threshold then renal out line has significant difference in the second experimental. And the third experimental has results because of a increased background nearby live and spleen.

• Journal of Oral Medicine and Pain
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• v.26 no.4
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• pp.309-318
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• 2001

The purposes of the study were (1) to evaluate the olfactory identification ability in those who have bad breath, (2) to determine the olfactory detection threshold for methyl mercaptan in normal subjects and those who have bad breath, and (3) to evaluate the effect of oral hygiene care on the olfactory detection threshold for methyl mercaptan. Sixteen male subjects with bad breath (male odor group), 9 male subjects without bad breath (male non-odor group), and 10 female subjects without bad breath (female non-odor group) were included for the study. Olfactory identification ability was assessed by administrating the Cross-Cultural Smell Identification Test (CC-SIT), and the olfactory detection threshold for methyl mercaptan was measured by two-alternative forced-choice single-staircase detection threshold procedure in a double-blinded condition. The geometric mean of the last four staircase reversal points of a total of seven reversals is used as the threshold. For the male odor group, after 1 month of intensive oral hygiene care for reducing oral volatile sulfur compounds (VSC) concentration, the olfactory detection threshold for methyl mercaptan was measured again and compared to the initial value. The ANOVA was used to test the group difference of olfactory threshold and olfactory identification ability and the paired t-test was used to test the difference of olfactory threshold between before and after reduction of oral VSC in male odor group. The results were as follows : 1. There was no significant difference in olfactory identification ability among those who have bad breath and normal male or female subjects. 2. The olfactory detection threshold for methyl mercaptan was about 8.4 ppb in normal male and female. 3. There was a tendency that male subjects with bad breath showed a higher olfactory detection threshold for methyl mercaptan when compared to those of no bad breath. 4. The olfactory detection threshold for methyl mercaptan returned to a normal level after 1 month of intensive oral hygiene care for reducing oral VSC.

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.4
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• pp.58-64
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• 1984

A simple model for the impurity profile in an ion-implanted channel layer of an enhancement type IGFET is assumed and a simple expression for the threshold voltage derived by using the assumed impurity profile is analyzed in detail. Also, this simple model is applied to simulating the substrate bias dependence of its threshold voltage. Excellent agreement is obtained between theory and experiment on n-channel devices. The error range of threshold voltage between gaussian-profile and box-profile is calculated in this paper and a new method of calculating the depth of ion-implanted Baler D is also introduced.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.38 no.10
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• pp.24-33
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• 2001

Delay, delay variation and packet loss rate are principal QoS(Quality of Service) elements of packet communication. This paper proposes a new buffer allocation mechanism to improve the packet loss performance in such a situation that multiple logical buffers share a single physical memory buffer. In the proposed buffer allocation mechanism, the movement of dynamic threshold follows a curved track instead of a straight line which is used in the DT(dynamic threshold) mechanism. In order evaluate the effectiveness of the proposed mechanism, it is compared with the existing previously proposed mechanisms in several aspects including NC(no control), ST(Static Threshold) and DT mechanisms.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.2
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• pp.897-913
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• 2016

Threshold signature is very important in identity authentication and some other applications. In December 2010, Chinese Encryption Administration released the SM2 elliptic curve digital signature algorithm as the first standard of the digital signature algorithm in China. At present, the papers on the threshold signature scheme based on this algorithm are few. A SM2 elliptic curve threshold signature scheme without a trusted center is proposed according to the Joint-Shamir-RSS algorithm, the Joint-Shamir-ZSS algorithm, the sum or diff-SS algorithm, the Mul-SS algorithm, the Inv-SS algorithm and the PM-SS algorithm. The proposed scheme is analyzed from correctness, security and efficiency. The correctness analysis shows that the proposed scheme can realize the effective threshold signature. The security analysis shows that the proposed scheme can resist some kinds of common attacks. The efficiency analysis shows that if the same secret sharing algorithms are used to design the threshold signature schemes, the SM2 elliptic curve threshold signature scheme will be more efficient than the threshold signature scheme based on ECDSA.

• Journal of Korean Public Health Nursing
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• v.26 no.1
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• pp.126-136
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• 2012

Purpose: The purpose of this study was to investigate the relationship among use of earphones, stress level, and hearing threshold in university students. Methods: Study subjects included 210 university students (76 men, 134 women). Data were collected by questionnaire and audiometer from December 17 to 20, 2011. The SPSS win 19.0 program was used for data analysis by descriptive statistics, t-test, one-way ANOVA, and Pearson's correlation coefficient. Results: 1) 4KHz, 6KHz hearing threshold of subjects who used earphones was higher than average hearing threshold of same age group. 2) Not significant differences in hearing threshold were observed according to frequency of use, and stress level. 3) Significant differences in 4KHz hearing threshold were observed according to earphone volume. 4) A significant positive correlation was observed between frequency of use and stress level (r=0.15, p<.05), earphone volume, and 4KHz hearing threshold (left) (r=0.15, p<.05); however, a negative correlation was observed between stress level and 4KHz hearing threshold (right) (r=-0.14, p<.05). Conclusion: A significant positive correlation was observed between frequency of use and stress level and earphone volume and 4KHz hearing threshold (left). Development of a program for hearing conservation is needed.