• Journal of Korea Water Resources Association
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• v.47 no.5
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• pp.447-457
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• 2014

This research focuses on the changes of return period for nonstationary rainfall data in which exceedance or nonexceedance probability varies depending on time. We examined two definitions of return period under nonstationarity and also performed nonstationary frequency analysis using the nonstationary Gumbel model to investigate variations of return period in Korea. Seogwipo, Inje, Jecheon, Gumi, Mungyeong, and Geochang were selected as subject sites of application. These sites have a trend in rainfall data as well as having more than 30 years data. As the results of application, the return periods considering nonstationarity are different with those considering stationarity. The differences of return periods between nonstationarity and stationarity increase as growing return period increases. In addition, the return period using the expected waiting time method shows lower value than that using the expected number of event method.

• Fashion & Textile Research Journal
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• v.3 no.4
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• pp.337-343
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• 2001

This study was purposed to see how men's hair styles of Japan had changed throughout history and results of the study was as follows. There are such evidences as topknots in its primitive styles and wooden combs that several hair styles were tried already in the primitive Jomon Period. In the Yayoi period, bare topknot style without crowns and Mizura style in which hair drop down both ears were popular. In the period of ancient burial mounds, Mizura style was dominative style and varied its form and shape according to classes and status. In the Aska and Nara era, topknot-in-the-crown style in which hair bound in one as in continental style and put in crown or hood, which style was influenced by the Sui and the Tang periods of China. Since the Heian period, topknot-in-the-Ebosi style, binding style, and Karawa style as well as topknot-in-the-crown style came in sight and Sakayaki style became popular in the Kamakura and Muromachi periods. In the Momoyama period, Chasenmage style and Ichomage style were spread widely. In the early Edo era, Wakashumage style and Yaromage style as well as Ichomage style were preferred. In the middle of Edo era in which form and shape of topknot was more distinct symbol of class, status and job than in any other period, Tachmach style under the influence of the Punkin and Honda modes. Sonno style was popular in the late Edo era. There was a drastic disappearance of topknot style by the hair-cutting order during the Meiji Restoration period and civilized hair style of the Jankiri style, a kind of dishevelled hair style without making a topknot was in fashion and continued to the present.

• The Journal of Natural Sciences
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• v.10 no.1
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• pp.123-131
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• 1998

This research was investigated the improved changes of Korean traditional costume after introducing the western costumes in this society. For this study microfilms of Chosun llbo, the popular newspaper since 1920s, and costume magazines for 1950s and 1960s were examined. The periods of the improved changing of Korean traditional costume were divided by the characteristics of qualitative and quantitative changes. Those were two, such as passive period and active period of change. At passive period, the change was not far from the original from of traditional costume and it was limited to the waist of skirt, length and width. But at active period, there was distinctive change from the previous period. Active period is divided by 2 sub-period again. In 1950s, the concept of darts of western costume was accepted to Korean costume and there was the western clothing for everyday costume, the characteristics of Korean costume were added to the base of the western clothing. It was named 'Arirang dress'. Original Korean costume had worn for special occasions since late 1950s.

• Korean Journal of Optics and Photonics
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• v.18 no.2
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• pp.142-148
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• 2007

A mechanically induced long-period fiber grating array was fabricated and its transmission characteristics were measured. The grating away consisted of a rubber cover and a 45 cm metal bar with 10 grating groups. Each grating group was composed of 60 gratings. The period of the grating of the grating groups was increased by $10{\mu}m$ increments from $690{\mu}m$ to $780{\mu}m$. The long period fiber grating was induced when the pressure was applied on the long period grating array and the resonant wavelength depended on the position of applied pressure. The experimental results shows that this long period fiber grating away can be used as a various band rejection filter or a fiber optic sensor.

• Journal of architectural history
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• v.19 no.6
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• pp.7-22
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• 2010

This study includes a review of the relevant literature and data on the Gyeolseong Eupseong, a coastal castle town of the Joseon Period. During the process of building the Gyeolseong Eupseong, Eupchi(administrative office) was transferred to several different locations for the following reasons:. first, to strengthen defensive capabilities by utilizing the locational advantages of the Seokdang Mountain Fortress, second, to secure sufficient space for holding the castle and have access to water in times of emergencies, third, to strengthen coastal defence by utilizing geographical advantages. Most of the Gyeolseong Eupseong was damaged during the Japanese colonial period. At present, there remain only part of the castle's facilities and some facilities that were restored later in modern times; 4 building sites have been identified. Remaining and destructed buildings can be identified through old maps(the local maps of 1872) and Zirizi and Eupzi(geography books). Also identified were 2 castle gate sites where a 1,500m-long stone castle wall and an ongseong(a crescent-shaped defensive structure), 5 chiseongs, and a most were constructed. The Gyeolseong area is assumed to have been a strategic foothold to defend the west coast from the days before the Three Kingdom Period. However it is very difficult to find any records created before the Joseon Period. Therefore, the time of the restoration of the Eupchi should be determined based on records created in the late Joseon Period. Finally, excavation work needs to be done to identify the locations of the castle's facilities.

• Journal of the Earthquake Engineering Society of Korea
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• v.15 no.1
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• pp.29-38
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• 2011

A new formula is proposed for the fundamental period of high-rise residential concrete shear-wall (SW) buildings. This formula, developed on the basis of dynamics with the recorded fundamental period during the recent earthquakes, can consider the wall stiffness with respect to any direction. To verify the proposed formula, the fundamental period of 10 sample buildings, measured during construction, is compared with the predicted fundamental period. Furthermore, the empirical formulas presented in the building codes KBC 2009 and ASCE 7-10, are also compared with the proposed formula to show a rationality of the proposed formula. The comparison results show that the proposed formula not only can rationally consider the characteristics of each shear-wall, but that it also accurately predicts the fundamental period of the buildings.

• Journal of the Korea Society for Simulation
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• v.27 no.3
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• pp.45-52
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• 2018

We consider the busy period of an M/G/1/K queueing system with queue-length-dependent overload control policy. A variant of an oscillating control strategy that was recently analyzed by Choi and Kim (2016) is considered: two threshold values, $L_1({\leq_-}L_2)$ and $L_2({\leq_-}K)$, are assumed, and service rate and arrival rate are adjusted depending on the queue length to alleviate congestion. We investigate the busy period of an M/G/1/K queue with two overload control policies, and present the formulae to obtain the expected length of a busy period for each control policy. Based on the numerical examples, we conclude that the variability and expected value of the service time distribution have the most influence on the length of a busy period.

• Journal of the Korea Convergence Society
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• v.8 no.4
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• pp.219-229
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• 2017

The study was conducted to find out lexical complexity and syntactic complexity for Korean learners by telling stories to see pictures. The results were as follows. First, there was no meaningful difference according to nationality. Second, we checked the differences on lexical complexity and syntactic complexity according to Korean studying period, only number of difference words showed meaningful difference among lexical complexity sub variables, but there was no difference among syntactic complexity sub variables. Third, we also checked correlation among staying period of Korea, Korean studying period, and other language related variables. It showed meaningful correlation staying period in Korea and other language related variable except Korean studying period and TTR. The directions for teaching Korean learners were suggested on the point of converge view according to results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.1019-1022
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• 2005

As recent information communication technology is rapidly developed, a lot of researches related to speech signal processing have been processed. So pitch period is applied as important factor to many application fields such as speech recognition, speaker identification, speech analysis and synthesis. Therefore, many algorithms related to pitch detection have been proposed in time domain and frequency domain and AMDF(average magnitude difference function) which is one of pitch detection algorithms in time domain chooses time interval from valley to valley as pitch period. But, in selection of valley point to detect pitch period, complexity of the algorithm is increased. So in this paper we proposed pitch detection algorithm using rotation transform of AMDF, that taking the global minimum valley point as pitch period and established a threshold about the phoneme in beginning portion, to exclude pitch period selection. and compared existing methods with proposed method through simulation.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.8 no.2
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• pp.193-203
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• 1996

Long period waves were measured at two stations outside and inside Chukpyon Harbor using two pressure-type wave gauges for one week that covers storm sea period. Based on the collected data the characteristics of long-period resonant oscillations were analysed: the resonant period corresponding to the peak spectral density are slightly different from one to the component wave period with the largest amplification ratio, and the latter period is suggested as that of the first resonant mode. From the analysed field data and numerical modeling, the first resonant mode of Chukpyon Harbor region appeared to be around 12 minutes with amplification ratio of 7, whose amplitude varies 10-20 cm inside of the harbour, and also the second mode appeared to be around 6 minutes. The waves of 2-3 minute periods were resonated apparently in the harbour, which is considered to be generated from group-bounded irregular waves and non-linear wave-wave interaction etc. The linearly decreasing reflection coefficients used in the numerical modeling appeared to be an alternative in calculating reflected waves in harbor.