• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.6B
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• pp.551-560
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• 2006

Security in WPAN is one of the most fundamental issues to overcome the barrier of wireless environment. Although piconet security mechanisms have been defined in the WPAN standards, many remains open and are left for implementation. Koinonia is a high-rate Wireless Personal Area Network (WPAN) technology, and is developed for multimedia traffic transmission in personal area. In Koinonia WPAN, a piconet consists of one master and more than one slave, and piconet security mechanisms is not defined at all. Therefore, we propose a robust piconet security mechanism for secure communications between slaves in a piconet. Based on security requirements analysis, our proposed protocols are shown to meet the security needs for Koinonia high-rate WPAN.

• Survey Research
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• v.3 no.1
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• pp.65-90
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• 2002

The purpose of this study is to develope an appropriate method of the household projection in Korea. Given the data constraints, the headship rate method is selected. This method is known to be responsive to changes in demographic factors related to household formation. To project future headship rates, the method of net transition rates based on the average of two-census intervals was adopted for household heads ages 35 and over, while the log-linear formula was employed for those aged under 35. The future headship rate of Korean males shows a one-peak pattern with plateau, whereas that of Korean females marks a two-peak pattern. For a better projection of household in the future, one-person households should be treated more carefully, because they are mostly either young adults or the elderly whose activities of household formation and dissolution are very hard to forecast.

• Journal of the Korean Society for Library and Information Science
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• v.28
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• pp.71-81
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• 1995

There are no exact copies or carvings of India's original Buddhist Scripts published in Korea that had been flowed into Japan except those of WanSanJungUiMongSanPuPo(환산정의몽산법어). YaWoonJaKyung (야운자경). KyeChoShimHakInMoon(계초심학인문) PalSimSooHangChang(발심수행장) and MongsanWhaSangPupoRackLock published by a mid-Chosun Dynasty Buddhist monk, YaWoon TaesunSa. Others are the translations by Chinese people. All printings were of woodblock except ChonjimyungYangsoo- RhockChapMoon(천지명양수육잡문) of Inkyng wood printing type. This shows perhaps that the Buddhists were so devout that they spared no effort in their prayers to head for the Paradise. Even the woodblock carver himself took his hard work for granted in his belief and engraved the blocks with all his heart taking his work as God-given task. Or. perhaps they to use wood-block printing as the demand for the Scripts soared. By the way. as the Koryo Dynasty took Buddhism as the state religion, it was natural that the Buddhist Scripts were published at TaeJangToKam (the publishing office) and were much encouraged. It is noteworthy. however, that not a few Buddhist Scripts had been published during the Chosun Dynasty despite its crack-down on Buddhism as the Confucianism was declared as the state principle. The Scripts were even published by such temples as MoonJooSa(문수사), MyoHeeAm(묘희암). SsangbongSa(쌍봉사). PyoHoonSa(표훈사), YooJupSa(유점사), YongJangSa(용장사). and AnShimSa(안심사). The fact that the Scripts were even published by KanKyungToKam(간경부감) leads us to reconsider the traditional way of thinking of the Chosun Dynasty as anti-Buddhist or flunkeyist. The historical fact that a record number of Buddhist publications had been transmitted to Japan - is it accidental? - This issue could well be another subject matter for further research. However, it should be noted that very few of above­mentioned Buddhist Scripts are found in present-day Korea.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.11 no.1
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• pp.20-33
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• 1999

The evolution of deep-sea waves is driven by energy input from wind, nonlinear energy transfer between wave components, and dissipation through whitecaps. A comparative study was implemented by the use of two wave models in which only the computation methods of nonlinear wave-wave interactions are different from each other. It was reaffirmed that the nonlinear interaction plays a central role in such phenomena that occurred during the spectral growth of wind-seas as down-shift of the spectral peak frequency, overshoot, undershoot, and formation of self-similar spectrum. Specifically, the directional distribution at high frequencies develops into bimodal form, which is attributed to the nonlinear interactions. As saturation stage is reached, spectral density at high frequencies becomes proportional to negative 4 power to the frequency. Perturbations introduced into the spectrum quickly vanished through the actions of the self-similar mechanism. Thus, the nonlinear transfer has important contribution to the stability of numerical ocean wave models.

• Korean Journal of Medicinal Crop Science
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• v.5 no.3
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• pp.217-224
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• 1997

The significant chemical components estimating the quality of green tea were compared and analyzed in the shoots of Korean native tea plants. The results are summarized as follows. The contents of total nitrogen in tea leaves were in range of $3.59{\sim}4.89%$, and the tea plants grown wildly in Bosong Daewonsa, Hwasun Ssangbongsa, Shunchun Changchun-ri, Hadong Ssanggyesa. and the cultivated tea plants in Kangjin Jangwon Sanup had higher contents of total nitrogen. The contents of tannin ranged from 12.5 to 18.3%. The contents of tannin of Kuryoi Chonunsa (18.3%), Kangjin Baekryonsa (16.7%) and Naju Bulhoisa (16.4%) were higher than those of Yangkwang Chonma-ri (12.5%), Hampyong Yongam-ri (12.7%) and Yosu Udu-ri (12.8%). The contents of caffeine were in range of $2.21{\sim}3.11%$. The contents of caffeine of Kwangju Shamae Dawon (3.11%), Kangjin Jangwon Sanup (2.94%) and Shunchun Changchun-ri(2.87%) were higher than those of Tamyang Yanggak-ri(2.21%), Yosu Udu-ri(2.23%) and Kuryoi Hwaomsa (2.23%). The contents of vit. C were in range of $167.9{\sim}223.5mg/100g$. The contents of vit. C of Changsong Oshan-ri (167.9mg/100g), Shunchun Shongkwangsa (185.6mg/100g) and Yongkwang Chonma-ri (185.8mg/100g) were lower than those of Kwangju Shamae Dawon (291.5mg/100g), Kangjin Jangwon Sanup (271.8mg/100g) and Shunchun Changchun-ri (269.5mg/100g). The contents of chlorophyll were in range of $187.4{\sim}332.7mg/100g$, and the mean contents were in range of 242.0mg/100g. The contents of total amino acids were in range of $1,888{\sim}2,500mg/100g$. The content of total amino acid at Kangjin Jangwon Sanup was the highest as 2,500mg/100g, and that of Shunchon Shongkwangsa was the lowest as 1,888mg/100g. Results of this study suggest that the native tea plants naturally grown at Bosong Daewonsa, Hwasun Ssangbongsa, Shunchun Changchun-ri, Hadong Ssanggyesa, and the cultivated tea plants at Kangjin Jangwon Sanup show excellent quality in terms of abundance of total nitrogen and total amino acids, and less contents of tannin.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.2
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• pp.45-58
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• 2012

For the development of reference values and evaluation of water quality in various environmental conditions, we divided the coastal region around Korean peninsular into 5 distinctive ecological regions based on the influence of surface current, depth, tidal range, turbidity, and climate condition. We used national marine environment monitoring data collected by National Fisheries Research & Development Institute(NFRDI) from 2000-2009. For the reference values, we used maximum seasonal mean from 2000 to 2007 for DIN, DIP, and chlorophyll-a and minimum seasonal mean for secchi depth measured at stations without the influence of river runoff in each ecological regions. For the reference value of bottom dissolved oxygen saturation, we used minimum mean value of 90% calculated from minimal riverine influence stations of whole regions. We calculated enrichment score for each assessment criteria. The enrichment score of DIN, DIP, and Chlorophyll-a was 1 (=< reference value), 2 (< 110% of reference value), 3 (< 125% of reference value), 4 (< 150% of reference value), and 5 (> 150% of reference value). The enrichment score of DO saturation and Secchi depth was 1 (> reference value), 2 (> 90% of reference value), 3 (>75 % of reference value), 4 (> 50% of reference value), and 5 (< 50% of reference value). We calculated water quality index using weighted linear combination of five enrichment score for the comparison of whole regions. From the water quality index distribution calculated from all stations between 2000 and 2007 period, we classified into 5 grade based on the standard deviation calculated from total water quality index. We assigned grade very good(I), good(II), moderate(III), bad(IV), and very bad(V) when the water quality index was less than 23, minimum + 1 sd, +2 sd, +3 sd, and grater than minium+ 3 sd, respectively.

• Korean Journal of Applied Biomechanics
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• v.18 no.1
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• pp.245-253
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• 2008

The purpose of this study was to analyze the effects of shoes with curved out-sole on the posture variation and its control strategy. At first, Target shoes(s) was made by evaluating the static postures of 7-female university students via 'New York State Posture Test' on shoes which made the relative angle between foot surface and ground surface of shoe change. At second, we evaluated muscle activity for 30-female university students(10 persons-3 groups) on shoes which were s(target), m shoes with curved out-sole and n shoes with flat out-sole. 1. The posture scores on New York State Posture Test were statistically different according to the relative angle changes, and the best angle for score was -7 degree but, the scores charts were like two humped camel at -2, -7degree. we made the shoe with -7 degree and curved out-sole. 2. s, m shoes with curved out-sole had graded muscle activities but, static posture on bare foot, there were the graded activity on gastrocnemius for s shoes and tibialis anterior for m shoes, but on shoes, only Gastrocnemius for s shoes.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.1
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• pp.11-19
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• 2013

As the temperature data show a distribution pattern with a number of peaks, assumption of normal distribution will result in a serious bias in the analysis. In this study, the Gaussian Mixture Distribution (GMD), a type of bimodal distribution, is presumed as a frequency distribution for the water temperature, in order to estimate the optimal parameter and to carry out the relation analysis between the optimal parameter and the basic statistical information such as mean and variance on the data. By the way, an estimation formulae to compute the frequency distribution of the data is developed by computing the parameters of GMD (i.e. ${\alpha}_1$, ${\mu}_1$, ${\sigma}_1$, ${\alpha}_2$, ${\mu}_2$, ${\sigma}_2$) by means of the major characteristic values, such as mean, standard deviation and skewness of the data. The formulae shows an excellent coincidence with the result from the observation data, in the RMS limit accuracy of 5%.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.5
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• pp.134-143
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• 2017

In the case of highway, there may be a large number of travel time groups when there are a bus exclusive lane, a rest area, a sleeping shelter, etc. in the corresponding section. In most of the conventional travel time estimation studies, one representative travel time (assuming normal distribution) group is assumed in the low sample collection state, and if it is out of the specified range, it is determined as outliers and then the travel time is estimated. However, if there is a bus exclusive lane, a rest area, or a sleeping shelter in the relevant section, such as the highway, the distribution of travel time will be in the form of a bi-modal or a multi-modal, rather than a regular distribution. Therefore, applying the existing estimation methodology may result in distorted results. To solve this problem, first, it should be reliable even in the case of insufficient number of samples. Second, we propose a methodology to select the representative time group among a number of time groups and to estimate the representative time using individual time data of the selected time group.

• The Journal of the Petrological Society of Korea
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• v.14 no.3 s.41
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• pp.157-168
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• 2005

Trachytic rocks among the bimodal metavolcanic rocks of the Gyemyeongsan Formation and adjacent areas are investigated. Some rocks reveal very high content of iron and most rocks show very high abundances of rare earth elements and high field strength elements. Most rocks show significant Eu negative anomaly, which can be interpreted as the result of plagioclase fractionation. Lack of noticeable Nb negative anomaly indicates not-involvement of crustal material in their generation, which excludes the arc environment or remelting of continental crust from their genetic process. Metatrachytes of the Gymyeongsan Formation are plotted within the within-plate environment of the tectonic discrimination diagram utilizing immobile high field strength element Nb and Y. They also show typical characteristics of A-type magma, such as high Ga content. Considering their affinity to Al-type of Eby (1992) and their age of 750 Ma (Lee et al., 1998), they seem to have been produced by the differentiation of mantle-derived within-plate magmatism at the rift, related with the separation of Neoproterozoic supercontinent Rodinia. Possible connection of Gyemyeongsan and Munjuri Formations of the Okcheon metamorphic belt, at least part of them, to the Cathaysia block of South China during the Neoproterozoic is strongly suggested.