• Structural Engineering and Mechanics
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• 제25권5호
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• pp.613-629
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• 2007

A finite element method (FEM) of B-spline wavelet on the interval (BSWI) is used in this paper to solve the static and vibration problems of thin plate. Instead of traditional polynomial interpolation, the scaling functions of two-dimensional tensor product BSWI are employed to construct the transverse displacements field. The method combines the accuracy of B-spline functions approximation and various basis functions for structural analysis. Some numerical examples are studied to demonstrate the proposed method and the numerical results presented are in good agreement with the solutions of other methods.

• 대한의용생체공학회:의공학회지
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• 제31권4호
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• pp.316-320
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• 2010

HRV(Heart rate variability) analysis parameter is widely used as an index to evaluate the autonomic nervous system and cardiac function. For reliable HRV analysis, we need to acquire the accurate ECG signals. Most of commercially available portable ECG devices have low sampling rate because of low power consumption and small size issues, which make it difficult to measure RR-interval accurately. This study is to improve the accuracy of RR-interval by developing R-wave interpolation technique, based on the morphological characteristics of the QRS complex. When the developed method was applied to ECG obtained at 200 Hz and the results were compared with 1000 Hz reference device, the error range decreased by 1.33 times in sitting and by 2.38 times in cycling exercise. Therefore, the proposed interpolation technique is thought to be useful to improve the accuracy of R-R interval in the portable ECG device with low sampling rate.

• 한국산학기술학회논문지
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• 제21권7호
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• pp.176-183
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• 2020

구조함은 수색 및 구조작업을 위하여 크게 세 가지 형태의 잠수체계(Diver Stage Diving, Wet Bell Diving 및 Scuba Diving)를 보유하고 있다. 어떠한 잠수체계를 활용하더라도 잠수요원이 잠수작업 완료 후 상승 시에는 잠수병 예방을 위하여 잠수작업수심 및 잠수 총 시간에 해당하는 감압표에 따라 감압절차를 준수하여야 한다. 감압절차는 크게 수중감압방법과 수중 및 함상감압을 병행하여 수행하는 방법으로 나뉘게 된다. 특히 수중 및 함상감압을 함께 수행하는 방법의 경우 U.S Navy Diving Manual에 따라 수중감압에서 함상감압으로 넘어가는 단계인 Surface Interval이 5분을 초과하지 않아야 한다. 하지만 실선 테스트결과 Wet Bell Diving에서 Surface Interval이 5분을 초과하는 문제점이 발생하였다. 이에 본 논문에서는 모든 가능한 원인을 식별하여 원인분석을 실시하고, 이를 바탕으로 개선된 Wet Bell Diving의 측정결과를 나타내었다. 그 결과 개선된 잠수체계의 실선 테스트에서 Surface Interval이 5분 이내 만족함을 확인하였다. 본 논문의 연구결과는 향후 잠수체계의 운용 및 개선에 유용한 자료로 활용될 것으로 판단된다.

• 복식
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• 제60권6호
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• pp.37-47
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• 2010

The purpose of this study was to investigate the effect of perceiver's gender, interval and color of checked pattern on clothing image. The experimental materials developed for this study were a set of stimulus and response scales. The stimuli were 16 color pictures, in which the perceiver's gender, interval(0.5cm, 1.5cm, 3.5cm, 5.5cm), and color(red, yellow, blue, purple) were manipulated. The 7-point scale was used for evaluation of clothing image. Data were obtained from 192 male college students and 192 female college students living in Seoul, Gwangju, Jinju, and Masan on December 2009. For data analysis, ANOVA and Duncan-test were used by using SPSS program. Results of this study were as follows.; Clothing image according to interval and color of checked pattern consisted of five dimensions of attractiveness, appeal, warmness, modesty, and freshness. Perceiver's gender showed an independent effect on appeal, modesty, and freshness. Interval showed an independent effect on appeal, warmness, modesty, and freshness. Also, interaction effects of Perceiver's gender and interval on appeal and freshness were found. Interaction effects of Perceiver's gender and color on appeal were found.

• 전기학회논문지
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• 제66권4호
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• pp.692-700
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• 2017

In this paper, we propose the structural design of Interval Type-2 FCM based RBFNN. Proposed model consists of three modules such as condition, conclusion and inference parts. In the condition part, Interval Type-2 FCM clustering which is extended from FCM clustering is used. In the conclusion part, the parameter coefficients of the consequence part are estimated through LSE(Least Square Estimation) and WLSE(Weighted Least Square Estimation). In the inference part, final model outputs are acquired by fuzzy inference method from linear combination of both polynomial and activation level obtained through Interval Type-2 FCM and acquired activation level through Interval Type-2 FCM. Additionally, The several parameters for the proposed model are identified by using differential evolution. Final model outputs obtained through benchmark data are shown and also compared with other already studied models' performance. The proposed algorithm is performed by using Iris and Vehicle data for pattern classification. For the validation of regression problem modeling performance, modeling experiments are carried out by using MPG and Boston Housing data.

• Geomechanics and Engineering
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• 제28권6호
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• pp.573-584
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• 2022

Water inrush may occur during seaside urban tunnel excavation. Various factors affect the water inrush, and the water inrush mechanism is complex. In this study, nine evaluation indices having potential effects on water inrush were analysed. Specifically, the geographic and geomorphic conditions, unfavourable geology, distance from the tunnel to sea, strength of the surrounding rock, groundwater level, tidal action, cyclical footage, grouting pressure, and grouting reinforced region were analysed. Furthermore, a two-step interval risk assessment method for water inrush management during seaside urban tunnel excavation was developed by a multi-index system and interval risk assessment comprised of an interval analytic hierarchy process, fuzzy comprehensive evaluation, and relative superiority analysis. The novel assessment method was applied to the Haicang Tunnel successfully. A preliminary interval risk assessment method for water inrush was performed based on engineering geological conditions. As a result, the risk level fell into a risk level IV, which represents a section with high risk. Subsequently, a secondary interval risk assessment method was performed based on engineering geological conditions and construction conditions. The risk level of water inrush is reduced to a risk level II. The results agreed with the current tunnel situation, which verified the reliability of this approach.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 심포지엄 논문집 정보 및 제어부문
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• pp.155-156
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• 2008

In this paper, an interval type-2 fuzzy logic system is designed and compared with a type-1 fuzzy logic system. To compare performance of a type-1 fuzzy logic system with the type-2 fuzzy logic system, we apply type-1 fuzzy logic system and type-2 system to modeling the noised data. Membership function of interval type-2 fuzzy logic system is designed consequents of rules including uncertainty. For general type-2 fuzzy logic system computational complexity is severe. On the other hand, theoretic and arithmetic computations for interval type-2 fuzzy logic systems are very simple.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1474-1479
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• 2003

This paper proposes a transmission interval which includes collisions and retransmissions in the IEEE 802.11 DCF. The transmission probability is used for the calculation of collisions and retransmissions in the DCF. Since the noises are considered to analyze the transmission interval, retransmissions by the noises are included in the proposed transmission interval. The proposed transmission interval takes account of the retransmissions by packet errors, and makes it possible to analyze the maximum throughput of the DCF.

• 한국항공운항학회지
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• 제14권4호
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• pp.87-93
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• 2006

The black-tailed gull chicks, Larus crassirostris, recognize various adult voice signal base on the simple patterns. We investigated behavior change in black-tailed gull chicks through physical manipulation of mew call. They were playback in four situations differing in physical character: 1) frequency manipulation only, 2) duration manipulation only, 3) call intensity(dB) manipulation only, and 4) call interval manipulation only. We observed occurrence of different response of the chicks, which were categorized into two behaviors(hidden and return behavior). The manipulated frequency, duration, and intensity were directly correlated. The chicks exposed to only manipulated call interval(0.5, 1sec) made significantly more hidden and return behavior. Adult black-tailed gull only increased flight time on manipulated call interval. The results suggest that black-tailed gulls use short call interval for alarm signal. The analysis of alarm signal provides an important on basic study of bird strike.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.191-197
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• 2009

As a case study on determining the replacement interval for the CMB contactor, we analyzed a field failure data during 59 months and through the simulation reliability is analyzed. As a result of analyzing the reliability we estimated parameters and analyzed distribution characteristics. Ultimately using the estimated results and applying the Age Replacement Policy considered the cost information, CMB contactor's replacement interval is determined. Through the comparison, analysis between the replacement interval and manufacturing company's, the necessity of replacement interval that is reflected in our operation circumstances is examined.