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Habitat Characteristics and Feeding Ecology of the Siberian Stone Loach Barbatula toni (Pisces: Namacheilidae) in the Bukcheon (Stream) (북천에 서식하는 종개 Barbatula toni(Pisces: Namacheilidae)의 서식지 특징 및 섭식생태)

  • Jeon, Yonglak;Ko, Myeong-Hun
    • Korean Journal of Ichthyology
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    • v.33 no.4
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    • pp.278-286
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    • 2021
  • The habitat characteristics and feeding ecology of the Siberian stone loach Barbatula toni were investigated in Bukcheon (Stream), Eocheonri, Ganseong-eup, Goseong-gun, and Gangwon-do, Korea from January to December 2013. B. toni lived in rapids or slow rapids from the upper stream to downstream, with the largest number of inhabitants in the middle-downstream regions. As a result of analyzing habitat preferences by age, 0+ and 1+ to ≥3+ showed differences. Ages of 0+(juveniles) lived mainly in rapidly flowing water (37.6±26.79 cm/sec) and low water depths (13.3±9.47 cm) in the pebble bottoms (substratum particle size 9.5±6.66 cm), but ages 1+ to ≥3+ lived mainly in relatively slowly flowing water (13.3±17.33 cm/sec) and relatively deep depths (25.9±10.31 cm) in stone and large stone bottoms (substratum particle size 18.0±7.63 cm). B. toni was mainly eaten from March to December when the temperature was above 5℃, and the amount of food eaten peaked in June and October. Their main food sources analyzed by the index of relative importance (IRI) included Diptera (57.0%), Ephemeroptera (29.3%), and Trichoptera (13.5%). The juveniles (age 0+) fed on small-sized prey such as Diptera and Trichoptera whales, but as they grew, they mainly ate large-sized Ephemeroptera. These feeding habits and changes in food according to the growth of B. toni were very similar to those of sibling species, B. nuda.

Characteristics of a New Sparassis latifolia Variety, "Hanyeoul", with Stable Pinheading (자실체 발생이 안정적인 꽃송이버섯 신품종 '한여울')

  • Choi, Jun-Yeong;Choi, Jong-In;Baek, Il-Seon;Shin, Bok-Eum;Kim, Jeong-Han;Ha, Tai-Moon;Jeong, Gu-Hyun
    • Journal of Mushroom
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    • v.20 no.3
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    • pp.107-112
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    • 2022
  • This study was conducted to reduce the phenomenon of biased cultivation and to pursue the diversification of mushroom items. We focused on developing Sparassis latifolia varieties with a short cultivation period, stable pinheading, and a high yield. We have collected and determined the characteristics of genetic resources domestically and abroad since 2016. We bred the unique domestic variety, "Hanyeoul" and the results of this study are as follows. The optimal temperatures for mycelial growth and fruit body growth were 22~25℃ and 19~21℃, respectively. The color of the pileus was pale-yellowish white, which was similar to the color of the control variety, "Neoul". The number of days required for cultivation was 125 for bottle cultivation and 98~102 for bag cultivation, which was shorter than the number of days required for the control variety. Bottle cultivation took 39 days shorter for the new variety than the control variety. The fruiting body of the new variety was similar in size or larger than that of the control variety. The pinheading rate was more than 90% in bottle cultivation and bag cultivation, which was more stable than pinheading in the control variety. The yield was 79.1 g/bottle (1,100 cc) for bottle cultivation, which was 22.6% higher than the yield of the control variety, and 641.1~689.5 g/bag (2.6 kg) for bag cultivation, which 5.8~10.4% higher than yield of the control variety.

A Study on Benefit/Cost Analysis of Re-Bar Connection Methods for Hyper Strength(SD500) Reinforcement (SD500철근 커플러 이음의 편익/비용분석에 관한 연구)

  • Kim, Jae-Yeob;Kwon, Yeo-Wool;Kim, Jun-Young
    • Journal of the Korea Institute of Building Construction
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    • v.8 no.2
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    • pp.81-87
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    • 2008
  • High-rise building is taking a place as one of building types from apartment housings to commercial buildings. With taking in account of stability and durability, strength of used materials is increasing gradually in these high-rise buildings. According to this, frequency in use of SD500 re-bar is increasing gradually in high-rise buildings. However the study of SD500 re-bar is insufficient because SD500 re-bar started to be used for domestic buildings lately. Specially because there is no guide or study to refer to, people get into difficulties when to decide the method of re-bar connection in construction using SD500 re-bar. Accordingly in this study, it suggests the method of estimating the economical efficiency on SD500 re-bar connection, and conducts benefit/ cost analysis on lapped splice and coupler splice by applying AHP theory, and then presents its result. After to analyze re-bar diameter of D25, 29, and 32, finally we attained the result that the coupler splice is advantageous in all parts of benefit/ cost more than the lapped splice.

An Analysis on Choice Factors of Food Court Customers to Co-Branding Strategies (공동 브랜드 전략을 위한 푸드 코트 이용고객의 선택속성 분석)

  • Hong, Yeo-Wool;Choi, In-Sub;Na, Tae-Kyun
    • Culinary science and hospitality research
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    • v.13 no.1 s.32
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    • pp.1-10
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    • 2007
  • Co-branding of food courts is turning into a trend with the activation of recent entrance of famous restaurants into shopping departments and other large-size buildings. This research analyzes the effects of co-brand food courts on the choices of dining enterprises by dealing with the customers of these newly activated food courts in shopping malls and large-size buildings. By analyzing the effects of the present status of customers' using food courts according to the characteristics of their choices of dining enterprises, food and brand elements were found to have an effect on the restaurant brand recognition of food courts, and price factor was found to have an effect on an visitors' recommendation intension. Therefore, customers who set importance on food and brand elements tend to take the brand of food courts into consideration as well; therefore, the maintenance of food quality and strengthening of brand image are mandatory in case of food court operation.

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Stability Evaluation of Flood Stage with Vegetation River Restoration (하천의 식생복원에 따른 홍수위 안정성 검토)

  • Kim, Byeong-Chan;Song, Joong-Geun;Kim, Min-Jeong;Lee, Jong-Seok
    • Proceedings of the Korea Water Resources Association Conference
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    • 2009.05a
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    • pp.2048-2052
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    • 2009
  • 최근 우리나라는 선진 외국과 같이 하천자연환경 보전에 대한 관심이 증가하고 있다. 이에 따라 하천은 단순한 치수 및 이수 뿐만 아니라 다양한 자연 그대로의 환경적 잠재기능을 복원하는 방향으로 전환되고 있다. 하천복원은 하도내 식생, 여울과 소, 기타 국부적인 자연 서식처를 제공하기 때문에 하천단면 축소, 하천식생에 의한 흐름과 조도 변화 및 하상의 변동으로 인하여 홍수해가 발생할 것이라는 역기능도 발생시킨다. 본 연구에서는 수위-유량자료가 부족한 하천 유역을 대상으로 생태공학적 접근을 고려한 식생 설치를 상정하여 하천의 식생복원에 따른 홍수위 안정성 검토를 실시하였다. 이를 위해, HEC-RAS를 이용하여 수리학적 요소들을 산출하고, 도출된 값들을 연직 2차원 수리해석에 입력하는 방법을 사용하여 대상구간의 식생 전 후 홍수위를 산정하였다. 그 결과, 식생전 후의 수위차는 $0.00^{\sim}1.25m$로 계산되어 식생으로 인해 최고 1.25m의 수위 상승 효과가 발생하였다. 가용할 자료가 부족한 하천의 식생복원에 따른 수리안정성 검토시 위 두 방법을 연계 이용한다면 하천복원 전후의 수리특성 변화를 정확히 파악할 수 있을 것으로 판단된다.

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Water Quality Improvement Characteristics in Fallow Paddy by the Shallow Pool and Shallows (휴경지의 웅덩이와 여울에 의한 수질정화특성)

  • Kim, Sun-Joo;Kim, Hyung-Jung;Kim, Phil-Shik;Jee, Yong-Geun;Yang, Yong-Seok
    • Journal of The Korean Society of Agricultural Engineers
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    • v.48 no.3
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    • pp.35-45
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    • 2006
  • Fallow paddy areas have been increased due to the import of cheap agricultural product, and the unbalance between farming cost and rice price since 1990. In domestic, rice production control that decrease paddy field area has been introduced for the control of rice demand and supply and stabilization of rice price since 2003. Because of the desire of paddy field's owner to create benefit by using paddy for other object, fallow paddy would be continuously increased. In the other aspect, many people in the world is suffering from hunger because of the shortage of food. In case of Korea, continuous drought and flood damages will be potential concern of stable food supply. From this viewpoint, the increasing fallow paddy area needs to be protected from the devastation by weed breeding for the re-cultivation. In this study, fallow paddy managed with the shallow pools and shallows was selected fur monitoring and analyzing of water quality and plant body change. As the results, the managed fallow paddy found to be effective in the purification of water quality and the control of plant growth.

Habitat Segregation between NE and NS Type of Zacco korean us (Cyprinidae) (참갈겨니, Zacco koreanus(잉어과)의 NE형과 NS형의 서식처 분리)

  • Chae, Byung-Soo;Yoon, Hee-Nam
    • Korean Journal of Ichthyology
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    • v.22 no.1
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    • pp.49-55
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    • 2010
  • Sympatric sites of type NE and NS of Zacco korean us were found in the upper reaches of many tributaries of the Nakdong and Seomjin rivers, as well as in some streams draining into the South Sea, Korea. In streams where the two types exist together, there was a tendency for individuals of NE to densely populate the upper reaches and those of NS to populate the middle reaches. A habitat-segregation phenomenon was observed in the cohabiting sites. Fishes of NE preferred rapids, whereas fishes of NS preferred slowly flowing or lentic regions. It seemed that the number of NE was proportional to the flow velocity, but NS showed an opposite trend in the cohabiting sites. On the other hand, such tendency was not found in regions where NE and NS exist separately.

The Evaluation of Stream Naturalness at Gokreungcheon River Basin (곡릉천 유역의 하천 자연도 평가)

  • Song, Hyung-Soo;Kim, Jin-Hong
    • Proceedings of the Korea Water Resources Association Conference
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    • 2011.05a
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    • pp.211-211
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    • 2011
  • 근래에 들어 환경문제의 사회적 부각과 함께 생태파괴적인 하천 정비 방식에 대한 대안으로 자연형 하천 환경 복원기법에 대한 시험 적용이 활발하게 진행되고 있다. 그러나 하천 복원에 앞서 하천 환경의 상태를 파악하고 진단할 수 있는 방법에 대한 연구가 미흡한 실정이다. 기존에 개발된 하천 질 평가 방법은 수질에 편향된 경향이 있으나 수질의 개선만으로는 생물 다양성의 발생 기반으로서 물리적 구조가 훼손된 상태에서는 생태적 복원의 효과를 달성하기 어렵다. 따라서 하천의 물리적 조건에 의한 구체적이고 비교적 객관적인 평가가 필요하며, 본 연구에서는 상기 평가를 바탕으로 작성된 하천 자연도 평가 지침에 의거하여 곡릉천 하류 일부 구간과 곡릉천의 지류인 벽제천을 대상으로 자연도를 조사하였다. 평가 결과 곡릉천 봉일천교 상류 2km구간의 저수로는 사행을 보였으며, 강변 사주 및 하중도는 없었으나 갈대 등과 같은 저수로변 식생이 있고 흙으로 조성된 인공제방으로 되어 있어 도심지의 정형화된 하천들에 비해 비교적 자연에 가까운 모습을 하고 있었다. 한편 하천 인근에 있는 아파트 등 주거지와 논, 밭 등의 경작지로 인한 오염원 유입 및 자전거 도로와 산책로 등 사람의 접근이 용이한 제외지의 이용으로 동식 물서식처로서의 기능이 저하될 것으로 우려된다. 곡릉천의 지류인 벽제천은 저수로가 사행을 유지하고 하중도와 사주가 형성되어 있으며 여울을 확인할 수 있었다. 하천 인근에 경작지와 제방도로가 있으나 인적이 드물고 차량 통행량이 적어 생태환경 훼손에 대한 우려는 적은 것으로 판단되 었다.

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EVP Models for Wave Transformation in Regions of Slowly Varying Depth (EVP방법(方法)을 이용한 완경사(緩傾斜) 영역(領域)에서의 파랑변형(波浪變形) 수치모형(數値模型))

  • Oh, Seong Taek;Lee, Kil Seong;Lee, Chul Eung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.12 no.3
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    • pp.231-238
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    • 1992
  • Error vector propagation method is applied to the elliptic mild slope equation in order to reduce the computation time. Results from the elliptic, parabolic, and hyperbolic models are compared with experimental data for an elliptic shoal. Also, results of the elliptic and hyperbolic models are compared with experimental data for a detached breakwater. As a result of applying this model. it is concluded that the present model satisfactorily reduces the computation time compared with other numerical models. In the accuracy of solutions, there are some oscillations but the trend compares well with other models.

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