• Title/Summary/Keyword: pattern

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Distribution Patterns of Macrobenthos during Recent Summer Seasons at the Bongam Sand Tidal Flat of Masan Bay, Korea (마산만 봉암갯벌에 서식하는 대형저서동물의 하계 분포양상)

  • Seo, Jin-Young;Kim, Jeong-Hyun;Choi, Jin-Woo
    • Korean Journal of Environmental Biology
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    • v.36 no.4
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    • pp.626-637
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    • 2018
  • In this study, a series of survey were conducted to identify the distribution patterns of macrobenthos at the Bongam sand tidal flat in Masan Bay. We collected macrobenthos at 9 sampling sites twice in June and September of every year from 2012 to 2017 using a box core sampler (collecting area, $0.025m^2$). There was a total of 50 species with a community density of $6,388ind.m^{-2}$ and a biomass of $313.9g\;wet\;m^{-2}$ during the study period. Polychaetes had the highest number of species and density among the macrofauna, but the mollusks had the largest biomass. The number of species ranged from 10 to 25 during study period but increased to over 20 species in 2014. The density which ranged from $1,508ind.m^{-2}$ to $12,008ind.m^{-2}$ rapidly increased in 2015. The dominant species were all polychaetes such as Heteromastus filiformis, Prionospio japonicus, Hediste diadroma, and Neanthes succinea. The mean diversity index ranged from 1.2 to 1.9, richness index from 1.2 to 2.4, and evenness index from 0.5 to 0.9. From the cluster analysis results, there was a spatial difference in the similarity of faunal composition of macrobenthos and this pattern was maintained throughout the study period, that is, the temporal similarities were higher than the spatial similarities. There was a change in community composition from June 2014 to June 2015 in most of the sampling sites. During this time, the dominant species also changed from H. filiformis and N. succinea to H. filiformis and H. diadroma. The density of opportunistic species such as Capitella capitata and Polydora ligni decreased compared to the early 2000s while the population of H. diadroma increased from 2015. There was little ecological information on H. diadroma such as when and where this species occurred.

Material Properties of Soil and Potteries Excavated From Ra-No.19 Site of Pung-nap Mudcastle (풍납토성 라-19호 출토 토양과 토기의 재료학적 특성)

  • Heo, Jun Su;Kim, Jo Yoon;Han, Ji Sun;Kim, Su Kyoung;Lee, Han Hyoung;Moon, Eun Jung;Yoo, Young Mi;Han, Min Su;Seo, Min Seok
    • Korean Journal of Heritage: History & Science
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    • v.45 no.3
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    • pp.194-211
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    • 2012
  • Pung-nap mudcastle has brought wide attention to archaeologists since scientific studies were carried out on the various types of building sites and excavated potteries related to A period of Baekje Kindom when it sat Hansung as the capital. It is identified that clay from Ra-No.19 site of Pung-Nap mudcastle has different from compositions that of residential soil. From archaeological point of view, it is believed that the the soil was a source material for potteries due to the appropriate viscosity and inclusions. Mineralogical and geochemical studies show that the compositions between the source material and randomly chosen two potteries from the same site are similar. Behavior pattern classification of major, trace and rare elements provides also very similar result. Artificial specimen has been made at different temperature in order to estimate firing temperature of the potteries by means of various kinds of instrumental application. As a result of the study, it is believed that the firing temperature of the red and brown pottery was $550{\sim}600^{\circ}C$ and $900{\sim}1,000^{\circ}C$ respectively.

Combination Effects of Large Dam and Weirs on Downstream Habitat Structure: Case Study in the Tamjin River Basin, Korea (대형 댐과 농업용 보가 하류 서식처 특성에 미치는 영향 연구: 탐진강 유역을 대상으로)

  • Ock, Giyoung;Kang, Ji-Hyun;Park, Hyung-Geun;Kang, Dong-Won
    • Korean Journal of Environmental Biology
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    • v.36 no.4
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    • pp.638-646
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    • 2018
  • The purpose of this study was to investigate the long-term habitat morphological alteration resulting from a large dam and weirs in the Tamjin River. To achieve this, we carried out a hydrograph analysis and a substrate size distribution analysis. We also estimated the channel width, bar area and vegetation encroachment using aerial photographs taken before and after the construction of the dam and weirs. The result of the hydrological analysis showed that flooding downstream was greatly reduced with small peaks occurrence after the dam construction. Interestingly, normal hydrographs in the main channel appeared just after tributary conjunction. There was a similar pattern in the substrate size analysis. Despite coarsened substrate just downstream of the dam site, more sand appeared again after introduction of the tributary. However, there was an increase in the bar area downstream of the dam's channels with most bars covered with vegetation. The channel width increased at the upper area of weirs through impoundment, but decreased downstream because of vegetation encroachment. This study indicate that unregulated tributary plays an important role in restoring hydro-physical habitat conditions in mainstream channels below a large dam. However, numerous weirs could be a causal factor to accelerate habitat deterioration in the dam downstream channels.

Mineralogical and Geochemical Characteristics of Earthenwares and Clay excavated from Hapsuri, Yeoncheon (연천 합수리 유적 출토 토기·토양의 광물학 및 지구화학적 특성)

  • Kim, Su Kyoung;Han, Lee Hyeon;Heo, Jun Su;Han, Min Su;Lee, Han Hyoung;Moon, Eun Jung;Seo, Min Seok
    • Korean Journal of Heritage: History & Science
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    • v.45 no.1
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    • pp.102-121
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    • 2012
  • The purpose of this study is to verify homoteneity of soil and earthenwares and identify firing temperature of earthenwares excavated from Yeoncheon Hapsuri: two earthenwares of the New Stone Age(YCP-1, YCP-2); two of the Bronze Age(YCP-3, YCP-4); and four of the Three States Age(YCP-4~8). The comparative analysis of soil (YCRM) and the earthenwares displays that soil geochemical patterns were similar to YCP-1, YCP-3, YCP-5, YCP-6, YCP-7 and YCP-8. On the other hand, YCP-2 and YCP-4 did not show the similarity to the one of soil because they had been enriched with MgO by contained talc and chlorite. Based on the absorption rate, specific gravity, structural characteristics and XRD analysis, firing temperature has been estimated: for YCP-7 and YCP-8 was $870^{\circ}C$ or over; for YCP-2 and YCP-4 $800^{\circ}C$ or below; and for YCP-1, YCP-3, YCP-5 and YCP-6 between 800 and $870^{\circ}C$. Mineralogical analysis displays that the geochemical pattern of the soil is coincide with the one around Yeoncheon Hapsuri site, which also shows similarity to the one of earthenwares. Such result persuades that the excavated earthenwares were produced with the soils within the precinct of the archaeological sites.

Archaeomagnetic Study of Historic Sites in Chungcheong Region Regional Difference of Geomagnetic Field and Issues on Reliability of Data (충청지역 유적에 대한 고고지자기학적 연구 지자기의 지역적인 차이와 데이터의 신뢰도 문제를 중심으로)

  • Sung, Hyong Mi
    • Korean Journal of Heritage: History & Science
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    • v.41 no.1
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    • pp.21-33
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    • 2008
  • In this study, the researcher examined archaeomagnetic secular variation of Chungcheong Region through measured data of archaeomagnet obtained from 34 relics, which discovered in the baked earth from varied historic sites within the region. Furthermore, the researcher closely reviewed regional differences of geomagnetic field in the domestic territory. Reviewing the comparison between the measured data of archaeomagnet in Chungcheong Region and the archaeomagnetic secular variation of Japan, which has difference in distance, it reveals a noticeable change in declination by tilting more than 10 degree toward East in the year of about A.D. 300, although the feature of whole variation is quite similar. In other period of times, it was confirmed that the regional differences of geomagnetic field in which the magnetic dip became deeper to some degree, and the declination was tilted westward a little bit. Such patterns do not differ significantly from the pattern of entire archaeomagnetic secular variation of our country, and even in the direct comparison to the data of Chungcheong Region, the distinct regional difference in both periods before and after Christian era was not confirmed. The fact may become clearer that, when the volume of the measured data of archaeomagnet increases further, and when more data connected with varied time period are filled, the problem such as deviation of the measurement period of archaeomagnet caused by the regional difference of geomagnetic field would not be worrisome issue, especially in Korean territory, judging from the measured data of archaeomagnet of historic relics in Chungcheong Region. Besides, as great efforts are being exerted in order to get the most reliable measured data as much as possible in taking both samples and measurement, it is thought that there would be no problem not only in the issue of deviation of the measurement period involving with the measured data of archeomagnet, but also in the aspect of reliability of data.

Use of digital scan data for evaluation of edentulous ridge relationship: A case report for removable prosthesis with unilateral cross bite (디지털 스캔 데이터를 활용한 무치악 치조제 관계의 평가와 인공치 선택: 편측 교차교합의 가철성 의치 수복 증례)

  • Kim, Jeong-Hoon;Kim, Jong-Eun;Park, Young-Bum;Lee, Keun-Woo
    • The Journal of Korean Academy of Prosthodontics
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    • v.57 no.3
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    • pp.304-311
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    • 2019
  • After the teeth were extracted, maxillary and mandibular alveolar ridges show the opposite resorption pattern and as a result, the mandibular arch is enlarged than maxillary arch relatively. In this situation, we should evaluate both alveolar ridge relationship and arrange the artificial teeth properly for stability of removable prosthesis. This case is a 77 years old male patient who wishes to make removable prosthesis and has atrophic alveolar ridge. By use of model scanner and CAD software, the angle between interalveolar crest line and occlusal plane was easily measured. Depending on the measurement, the artificial teeth are arranged in unilateral cross bite and after completion, patient was satisfied with the denture which showed proper stability, retention, support.

A Study on the Structural Features of the Joseon Royal Tomb Tumulus (조선왕릉 봉분의 구조적 특성에 대한 일고 - 문헌에 기록된 석실과 회격의 구조를 중심으로 -)

  • Jeon, Na Na
    • Korean Journal of Heritage: History & Science
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    • v.45 no.1
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    • pp.52-69
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    • 2012
  • This paper attempts to analyze the inner and outer structure of royal tombs that were built during the Joseon Period. This analysis is based on the relevant historical records and they were restored through visual composition in order to compare the features of Joseon royal tombs with those of Goryeo royal tombs and common tombs of the Joseon Period. Royal tombs of the Joseon Dynasty are structurally solid and contain a variety of artistic ornaments that symbolize guardian deities both inside and outside to protect the owners of the tombs for a long time. According to historical records such as Sejong sillok oryeui (Five Rites of State from the Annals of King Sejong) and Gukjo oryeui (Five Rites of State), it is presumed that the inner structure of royal tombs dating back to the early Joseon Period consisted of a stone chamber and that the byeongpungseok and nanganseok were built outside of the tomb. However, ever since King Sejo left it in his will not to make a stone chamber in his tomb, the royal tombs began to follow a new pattern, a burial pit outside the coffin filled with lime powder. Gukjo sangnye bopyeon (Supplement Book of the State Funeral Rites), which was compiled during the reign of King Yeongjo, is a book that shows how the royal tombs were formed in the late Joseon Period. The book explains in detail how lime powder was used to fill the burial pit of royal tombs. The byeongpungseok used during the late Joseon Period were engraved with peony flowers, while those previously made were engraved with twelve spirit warriors. Peony designs were frequently used to decorate the items of royal families, and the use of peony designs in tombs reflects the idea of regarding the royal tombs as an everyday living space for the deceased.

A Study on the Composition of HonJeon(魂殿) space (조선시대 혼전(魂殿)공간의 구성에 관한 연구)

  • Hong, Eun Ki;Kim, Sang Tae;Chang, Hun Duck
    • Korean Journal of Heritage: History & Science
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    • v.45 no.4
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    • pp.74-91
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    • 2012
  • This study puts its focus on Honjeon space which relatively small number of precedent studies chose as a subject of a study. The objective is to analyze Honjeon space's spatial relationship and palaces that consist Honjeon through analysis of spatial configuration and elements that affected construction of Honjeon space. The Royal Funeral, among other ceremonies of Joseon Dysnasty, carries religious characteristic along with functional and structural characteristics. By analyzing "National Five Rites", "Uigwe for the State Funeral 魂殿都監儀軌", and "Annals of Joseon Dynasty", the study organized elementary details about Honjeon space and surrounding spaces to determine the symbolism of Honjeon space's location at each palace and compared them to see if any systematical features existed between Honjeon spaces of each palace. Through this study, it was apparent the king mainly used Jaseongdang Hall of Gyeongbokgung in the early period of Joseon Dynasty and he mainly used Sunjeongjun of Changdeokgung while the queen used Munjeongjun of Changgyeonggung as the time reached the later period of Joseon Dynasty. Also in determination of Honjeon space, the study found that there were records of avoiding Pyeonjeon space in need for political space. The study also determined that places other than Pyeonjeon space was intended to be used for Honjeon space through the analysis which indicates that spaces that were initially used as Pyeonjun in the early Joseon Dynasty and simultaneously as Honjeon space were moved due to changes made in terms of theirs usages. Through the study, it could be also known that primary spaces of Honjeon was composed accordingly to "National Five Rites" and constant pattern of spaces existed among buildings near Honjeon which were arranged according to each palace's characteristic.

Shear Strength of SFRC Deep Beam with High Strength Headed Reinforcing Tensile Bars (고강도 확대머리 인장철근을 가지는 SFRC 깊은 보의 전단강도)

  • Kim, Young-Rok;Lee, Chang-Yong;Kim, Seung-Hun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.5
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    • pp.111-117
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    • 2019
  • Shear experiments were carried out to evaluate shear performance of SFRC deep beams with end-anchorage of SD600 high strength headed reinforcing tensile bars. The experimental variables include the end-anchorage methods of tensile bars (headed bar, straight bar), the end-anchorage lengths, and the presence of shear reinforcement. Specimens with a shear span ratio of 1 showed a pattern of the shear compression failure with the slope cracks progressed after the initial bending crack occurred. Specimens with end-anchorage of headed bars (H-specimens) showed a larger shear strengths of 5.6% to 22.4% compared to straight bars (NH-specimens). For H-specimens, bearing stress reached 0.9 to 17.2% of the total stress of tensile bars up to 75% of the maximum load, and reached 22.4% to 46%. This shows that the anchorage strength due to the bearing stress of headed bars has a significant effect on shear strength. The experimental shear strength was 2.68 to 4.65 times the theoretical shear strength by the practical method, and the practical method was evaluated as the safety side.

Analysis of Haircut Preference of Korean Women in Age of the 4th Industrial Revolution (4차 산업혁명시대 한국 여성들의 헤어커트 선호도 분석)

  • Son, Gwang Hyun;Park, Jang Soon
    • Journal of the Korea Convergence Society
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    • v.10 no.7
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    • pp.311-316
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    • 2019
  • The purpose of this study is to analyze the preference of haircut according to demographic factors such as age, education, marital status, occupation, monthly income, and residence in order to contribute to the establishment of hair trends of Korean women living in the 4th industrial age. Respectively. After the questionnaire was distributed, 305 questionnaires were analyzed statistically. According to the results of the questionnaire survey, it was found that the higher the age group was, the higher the gradation pattern was, and the difference was statistically different according to the demographic characteristics (p<0.05). By analyzing the shapes and differences of female haircuts according to these demographic characteristics, we will contribute to the establishment of sophisticated and innovative hair trends of Korean women living in the era of the fourth industrial revolution. Through this study, we can find the most ideal hairstyle for Korean women and it will be a starting point for development of various new and creative hairstyles. It is also used as basic data for hairdressing education and it will be actively used as an objective index that can express women 's personality clearly.