• The Research Journal of the Costume Culture
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• v.24 no.6
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• pp.873-885
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• 2016

It is common knowledge that a conventionally woven textile consists of two assemblies of parallel threads (warp and weft), one interlaced with the other at ninety degrees. Where each of the two assemblies is arranged in a particular colour sequence, a check design, known as a 'tartan', may be created. Although similar check-type cloths have been produced worldwide, it is the tartans of Scotland which have received most attention and it is here that a complex set of rules evolved and tartans of different types became associated traditionally with different regions, family groups or 'clans'. There is an impressive array of publications focused on the identification of tartans and their clan associations. This paper explains the nature of tartans, analyses typical surface structures, ratios and proportions, and suggests possible avenues of use for modern designers. The principal sources of data were a collection of tartans held at ULITA - An Archive of International Textiles (University of Leeds, UK) and Stewart's 1974 publication The Setts of Scottish Tartans. Based on the observation that divisions into halfs and thirds were dominant, a series of templates is presented with the intention of developing an awareness among designers that ratios and proportions used in familiar or traditional frameworks can be employed in a modern context.

• Journal of Industrial Technology
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• v.21 no.A
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• pp.329-336
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• 2001

In this study, a series of fatigue tests are carried out in order to estimate quantitatively the characteristics of fatigue crack growth rate for high strength steels of SM570, POSTEN60, and POSTEN80 steel, that is, the influence on fatigue crack growth rate according to the welding line, the characteristics of fatigue crack growth according to the welding method and the kinds of steel, and the characteristics of fatigue crack growth for base metal, heat affected zone and weld metal. From the test results, in case that the notch if parallel to welding line, it knows that the retardations of fatigue crack growth rate in crack tip at early stage increase remarkably than in case that the notch is perpendicular to welding line due to compressive residual stress. And the characteristics of fatigue crack growth rate according to welding method are that the dispersion of fatigue crack growth rate in case of FCAW method is smaller than that of SAW method. Also, it knows that the fatigue crack growth rate converges in high stress intensity factor range.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1993.10a
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• pp.240-247
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• 1993

The precise prediction of reserved carrying capacity of bridge as a system is extremely difficult especially when the bridges are highly redundant and significantly deteriorated or damaged. This paper is intended to propose a new approach for the evaluation of reserved system carrying capacity of bridges in terms of equivalent system-strength, which may be defined as a bridge system-strength corresponding to the system reliability of the bridge. This can be derived from an inverse process based on the concept of FOSM form of system reliability index. It may be emphasized that this approach is very useful for the evaluation of the deterministic system redundancy and reserve strength which are measured in terms of either probabilistic system redundancy factor and reserve factor or deterministic system redundancy factor and reserve factor. The system reliability of bridges is formulated as a parallel-series model obtained from the FAM(Failure Mode Approach) based on the major failure mechanisms. AFOSM and IST methods are used for the reliability analysis of the proposed models. The proposed approach and method for the system redundancy and reserve safety/strength are applied to the safety assessment of actual RC and steel box-girder bridges. The results of the evaluation of reserved system safety or bridge system-strength in terms of the system redundancy and the system safety/strength are significantly different from those of element reliability-based or conventional methods.

• Progress in Superconductivity
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• v.6 no.2
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• pp.113-117
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• 2005

In this study, electromagnetic analysis of current paths including meander pattern, spiral pattern, and bi-spiral pattern were performed and in order to verity the analysis results, experiments tests including quench test, and insulation tests were performed. In addition, bubble corner concepts were introduced to enhance insulation reliability. From our study, bi-spiral pattern of YBCO thin films were rather effective for quench and insulation than the other patterns. So this current path pattern was adopted for YBCO thin films in order to develop 6.6 kV resistive fault current limiters. Finally YBCO thin films were connected in series and parallel to enhance capacity, and the test results of current limiting characteristics of 6.6kV resistive SFCL were successful. The Progress in Superconductivity is published every six month and serves as a channel for publications on superconductivity and related topics. The author(s) are required to submit THREE copies of the manuscripts along with original figures directly to the Editor.

• Progress in Superconductivity
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• v.7 no.1
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• pp.36-40
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• 2005

The problem of fluctuation-induced digital errors in a rapid single flux quantum (RSFQ) circuit has been a very important issue. In this work, we calculated the bit error rate of an RSFQ switch used in superconductive arithmetic logic unit (ALU). RSFQ switch should have a very low error rate in the optimal bias. Theoretical estimates of the RSFQ error rate are on the order of $10^{-50}$ per bit operation. In this experiment, we prepared two identical circuits placed in parallel. Each circuit was composed of 10 Josephson transmission lines (JTLs) connected in series with an RSFQ switch placed in the middle of the 10 JTLs. We used a splitter to feed the same input signal to both circuits. The outputs of the two circuits were compared with an RSFQ exclusive OR (XOR) to measure the bit error rate of the RSFQ switch. By using a computerized bit-error-rate test setup, we measured the bit error rate of $2.18{\times}10^{-12}$ when the bias to the RSFQ switch was 0.398 mA that was quite off from the optimum bias of 0.6 mA.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.3
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• pp.373-379
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• 2012

This paper presents a fault location algorithm based on the adaptively estimated value of the local sequence source impedance for faults on a parallel transmission line. This algorithm uses only the local voltage and current signals of a faulted circuit. The remote current signals and the zero-sequence current of the healthy adjacent circuit are calculated by using the current distribution factors together with the local terminal currents of the faulted circuit. The current distribution factors consist of local equivalent source impedance and the others such as fault distance, line impedance and remote equivalent source impedance. It means that the values of the current distribution factors can change according to the operation condition of a power system. Consequently, the accuracy of the fault location algorithm is affected by the two values of equivalent source impedances, one is local source impedance and the other is remote source impedance. Nevertheless, only the local equivalent impedance can be estimated in this paper. A series of test results using EMTP simulation data show the effectiveness of the proposed algorithm. The proposed algorithm is valid for a double-circuit transmission line system where the equivalent source impedance changes continuously.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.2
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• pp.95-101
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• 2014

In this paper, UPS, with a built-in instantaneous sag drop compensation features, was developed to improve performance. The improved UPS, using instantaneous moving average method, compensates by quickly measuring the voltage and series inverter of half-bridge type, using line-interactive method that links with the voltage of the battery and power source, was developed. In addition, by developing a parallel inverter that uses a high-efficiency PWM switching method, overall UPS system was enhanced. To verify the performance of the proposed algorithm, single-phase 5[kVA] UPS systems were designed and the experimental system was constructed. The low-cost type of Cortex-M3 module CPU STM32F103R8T6 (32[bit]) is attached and the switching time of mode transfer was set within 4 [ms]. THD of the linear load operates in less than 3[%], and the stability of the output voltage operates in approximately ${\pm}2[%]$ range. The superior performance of the operations was confirmed with the system set as above.

• Composites Research
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• v.15 no.5
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• pp.27-34
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• 2002

The purpose of this study is to measure and predict the thermal conductivity of CF3327 plain-weave fabric composite made by Hankuk Fiber, Co. An experiment apparatus based on the comparative method has been made to measure the thermal conductivities of the composite material. Its accuracy was proved by measuring the thermal conductivity of graphite which is well-known. Micro-mechanical approaches are useful to assess the effect of parameters such as fiber and matrix material properties, fiber volume fraction and fabric geometric parameters on the effective material properties of composites. In this study, prediction was based on the concept of three dimensional series-parallel thermal resistance network. Thermal resistance network was applied to unit ceil model that characterized the periodically repeated pattern of a plain weave. The numerical results were compared with experimental one and good agreement was observed. Also, the effects of fiber volume fraction on the thermal conductivity of several composites has been investigated.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.8 s.239
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• pp.1070-1077
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• 2005

The $40\%$ of wall thickness criterion which has been used as a plugging rule is applicable only to a single cracked steam generator tubes. In the previous studies performed by authors, several failure prediction models were introduced to estimate the plastic collapse pressures of steam generator tubes containing collinear or parallel two adjacent axial through-wall cracks. The objective of this study is to examine the failure prediction models and propose optimum ones for non-aligned two axial through-wall cracks in steam generator tubes. In order to determine the optimum ones, a series of plastic collapse tests and finite element analyses were carried out for steam generator tubes with two machined non-aligned axial through-wall cracks. Thereby, either the plastic zone contact model or COD based model was selected as the optimum one according to axial distance between two clacks. Finally, the optimum failure prediction model was used to demonstrate the conservatism of flaw characterization rules for various multiple flaws according to ASME code.

• Wind and Structures
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• v.31 no.4
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• pp.363-371
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• 2020

Proper understanding of offshore wind speed variability is of essential importance in practice, which provides useful information to a wide range of coastal and marine activities. In this paper, long-term wind speed data recorded at various offshore stations are analyzed in the framework of fractal dimension analysis. Fractal analysis is a well-established data analysis tool, which is particularly suitable to determine the complexity in time series from a quantitative point of view. The fractal dimension is estimated using the conventional box-counting method. The results suggest that the wind speed data are generally fractals, which are likely to exhibit a persistent nature. The mean fractal dimension varies from 1.31 at an offshore weather station to 1.43 at an urban station, which is mainly associated with surface roughness condition. Monthly variability of fractal dimension at offshore stations is well-defined, which often possess larger values during hotter months and lower values during winter. This is partly attributed to the effect of thermal instability. In addition, with an increase in measurement interval, the mean and minimum fractal dimension decrease, whereas the maximum and coefficient of variation increase in parallel.