• Title/Summary/Keyword: field investigation

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Diversity on Necrophagous Insect of the Water Deer Carcass Decaying (고라니 사체 부패 진행에 따른 시식성 곤충 다양성에 관한 연구)

  • Yoon, Joo Hyuk;Choi, Mi-Jung;Park, Jong Kyun
    • Korean journal of applied entomology
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    • v.61 no.1
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    • pp.239-248
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    • 2022
  • Forensic entomology is a study that purposes at field reconstruction through insects attracted to carcasses, and has been mainly studied using carcasses such as a pig and chicken. Therefore, this study was conducted to find out if there is a singularity by using the carcass of water deer with different conditions and shapes of the hair quality and to find out the appearance of a necrophagous insect. The water deer carcass was received from the Jeollanam-do Wildlife Rescue Management Center and research was conducted. From May 19 2021 to July 2 2021, the decay progress of the carcass was observed for about 6 weeks. A total of 51 species of 21 families in 4 orders of insects were collected. Even after the carcass completely decays, even at the stage where the activity of other insects is not observed, insects such as Dermestidae and Tenebrionidae are collected from the hairs and leather of water deer carcass until the last. It was confirmed that insects of the order Coleoptera other than Diptera can be used as forensic entomological data related to the decay of carcasses with fur.

Investigation on relative contribution of flow noise sources of ship propulsion system (선박 추진시스템 유동 소음원 상대적 기여도 분석)

  • Ha, Junbeom;Ku, Garam;Cheong, Cheolung;Seol, Hanshin;Jeong, Hongseok;Jung, Minseok
    • The Journal of the Acoustical Society of Korea
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    • v.41 no.3
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    • pp.268-277
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    • 2022
  • In this study, each component of flow noise source of underwater propeller installed to the scale model of the KVLCC2 is investigated and the effect of each noise source on underwater-radiated noise is quantitatively analyzed. The computation domain is set to be the same as the test section of the large cavitation tunnel in the Korea Research Institute of Ship and Ocean Engineering. First, for the high-resolution computation of flow field which is noise source region, the incompressible multiphase Delayed Detached Eddy Simulation is performed. Based on flow simulation results, the Ffowcs Williams and Hawkings integral equation is used to predict underwater-radiated noise and its validity is confirmed through the comparison with the tunnel experiment result. For the quantitative comparison on the contribution of each noise source, the spectral levels of sound pressure and power levels predicted using propeller tip-vortex cavitation, blade surface and rudder surface as the integral region of noise sources are investigated. It is confirmed that the cavitation which is monopole noise source significantly contributed to the underwater-radiated noise than propeller blades and rudder which is dipole noise source, and the rudder have more contribution than propeller blades due to the influence of the propeller wake.

Effect of Planting Time on Seed Production of Vegetable Soybean at Different Locations (풋콩 재배지에 따른 파종시기가 종자생육에 미치는 영향)

  • Baek, In-Youl;Shin, Doo-Chull;Park, Chang-Kie;Lee, Jin-Mo;Suh, Hyung-Soo
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.40 no.1
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    • pp.44-51
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    • 1995
  • This investigation was conducted to determine the effect of the optimum planting date and place for good seed production on growth variation, grain yields, different of variety, infection of seed by fungi, and seed germination and vigor after room storage. Early maturity Korean soybean variety, Keunolkong, and introduced vegetable soybean variety, Fukura-edamame, were planted at field of YAES. and high cool land of Sajapyong in Milyang(altitude, 850m) on May 15 (early), June 15 (mid.), and July 15 (late) in 1991. The emergence and vegetative period gradually increased in the early planting date. The grain yield, seed weight, pod number, healthy grain yield also increased when Keunolkong was planted on early date. The healthy seed rate, Keunolkong increased in the early planting date, whereas that of Fukura also increased in the late planting date. Infection ratio of grain to phomopsis seed decay (Phomopsis spp. ' Diaporthe phaseolorum) in Fukura steadily increased in the early planting date. Infection ratio of grain to purple seed stain (Cercospora kikuchii) generally increased in the mid and late planting date. The seed germination and seedling vigor after room storage from five to six months gradually increased in the late planting date. And seed germination of Fukura rapidly decreased in the early planting date. Therefore, the optimum planting date for good seed production in early maturity vegetable soybean was June 15 in terms of harvesting time avoid a high temprature and humidity.

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An Investigation for Driving Behavior on the On-Ramp Merging Section in Urban Underground Roads Using a Driving Simulator (주행 시뮬레이터를 활용한 도심 지하도로 유입연결로 합류부 주행행태 분석)

  • Seungwon Jeong;Soohwan Kim;Dongmin Lee;Gunki Jung
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.21 no.6
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    • pp.97-114
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    • 2022
  • Unlike ground roads, the on-ramp merging section of underground roads cannot be seen by drivers of main road due to tunnels. In this study, a driving simulator was used for analysis, and virtual driving experiments were carried out to assess the driver's visibility for different design factors. The driver's driving behavior was analyzed by setting scenarios considering the length of chevron markings and the approach speed from the main road. The results of the analysis were used to determine the design factors for ensuring visibility when constructing the virtual driving environment for each scenario. These factors, including speed, lane change points, and driver's gaze ratios, were reviewed for significance using a statistical approach. As a result, in scenarios with a higher approach speed from the main road, it was discovered that there was a difference in driver's behavior between specific scenarios depending on the length of the section with chevron markings. Based on these findings, this study suggests implications and feasible solutions to improve driver safety on the on-ramp merging section of underground roads.

Risk Assessment Improvement Method of Small Stream When Small Sized Hazard Infrastructures Survey (소규모 공공시설 조사시 세천의 위험도 평가 방안)

  • Jungsoo Rho;Kyewon Jun;Jaesung Shin
    • Journal of Korean Society of Disaster and Security
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    • v.16 no.1
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    • pp.23-35
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    • 2023
  • Recently, the damage caused by natural disasters such as typhoons and localized torrential rains has been increasing rapidly. The Ministry of the Interior and Safety enacted a 「law on safety management of small sized infrastructures」 and local governments have to register small sized infrastructures with the National Disaster and Safety Management System (NDMS) until March 31st every year. Recently, each local government has ordered Safety inspections of small sized infrastructures and maintenance plans and six types of facilities, including small streams, small bridges, farm roads, access roads to village, inlet weirs, and drop structures are being surveyed and digitized into a database. Each facility is being evaluated for risk, and for those deemed hazardous, maintenance plans are being developed. However, since the risk assessment method of small sized infrastructures is not clear so that is conducted through visual investigation by field investigators, risk assessment is conducted in a subjective and ambiguous form. Therefore, this study presented a reasonable and quantitative risk assessment method by providing a quantitative evaluation indicator for small stream, which has the highest disaster risk among other small sized infrastructures, so that small sized hazard infrastructures can be selected to secure transparent evidence for improvement plans and action plans.

Action Research on Reading Picture Books for Lower-Grade Multicultural Students from Foreign Backgrounds: A Case of Collaborative Lessons with A Elementary School Library (저학년 외국인 가정 다문화 학생을 위한 그림책 읽어주기 수업에 관한 실행연구 - A초등학교 학교도서관 협력수업의 사례를 중심으로 -)

  • Hyounmee Wee;Miah Cho
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.34 no.3
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    • pp.59-87
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    • 2023
  • The aim of this study is to provide practical instances of implementing picture book reading sessions within school libraries to enhance language proficiency and foster emotional stability among lower-grade multicultural students hailing from foreign backgrounds. The research outlines the design and execution of a picture book reading program tailored for multicultural students, with analysis based on the outcomes of actual classroom implementations. In the course of the study, existing literature pertaining to the use of picture books for enhancing multicultural education and language skills was reviewed. This informed the development of a structured class procedure by extracting core components. Indeed, 43 multicultural students in five classes in the first and second grades of A Elementary School in Gyeonggi-do were given three pilot classes for each class for 20 weeks and a total of 100 picture book reading classes, each with 17 main lessons. This study establishes the positive impact of picture book reading classes on the Korean language comprehension of multicultural students. The results confirm positive improvements in students' ability to understand Korean, as evidenced by enhanced Korean expression and presentation skills, increased library usage, and a positive shift in classroom attitude. The procedure for reading picture books using school libraries proposed in this study was actually conceived and developed in the course of class operation in the school education field, reflecting the changes brought about by the increase of multicultural students and the need to improve the class environment. Through this practical investigation, important insights have been extracted regarding how picture book reading sessions designed for elementary school students from multicultural backgrounds can enhance the classroom environment and elevate learning outcomes.

A Study on the Application of Non-destructive (Ultrasonic) Inspection Technique to Detect Defects of Anchor Bolts for Road Facilities (도로시설물 적용 앵커볼트 결함 검출을 위한 비파괴(Ultrasonic) 검사 기법 적용에 대한 연구)

  • Dong-Woo Seo;Jaehwan Kim;Jin-Hyuk Lee;Han-Min Cho;Sangki Park;Min-Soo Kim
    • Journal of Korean Society of Disaster and Security
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    • v.15 no.4
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    • pp.11-20
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    • 2022
  • The general non-destructive inspection method for anchor bolts in Korea applies visual inspection and hammering inspection, but it is difficult to check corrosion or fatigue cracks of anchor bolts in the part included in the foundation or in the part where the nut and base plate are installed. In reality, objective investigation is difficult because inspection is affected by the surrounding environment and individual differences, so it is necessary to develop non-destructive inspection technology that can quantitatively estimate these defects. Inspection of the anchor bolts of domestic road facilities is carried out by visual inspection, and since the importance of anchor bolts such as bridge bearings and fall prevention facilities is high, the life span of bridges is extended through preventive maintenance by developing non-destructive testing technology along with existing inspection methods. Through the development of this technology, non-destructive testing of anchor bolts is performed and as a technology capable of preemptive/active maintenance of anchor bolts for road facilities, practical use is urgently needed. In this paper, the possibility of detecting defects in anchor bolts such as corrosion and cracks and reliability were experimentally verified by applying the ultrasonic test among non-destructive inspection techniques. When the technology development is completed, it is expected that it will be possible to realize preemptive/active maintenance of anchor bolts by securing source technology for improving inspection reliability.

Geotechnical Engineering Characteristics of Ulleung Basin Sediment, East Sea (동해, 울릉 분지 심해토의 지반공학특성)

  • Lee, Chang-Ho;Yun, Tae-Sup;J.C., Santamarina;Bahk, Jang-Jun;Lee, Jong-Sub
    • Journal of the Korean Geotechnical Society
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    • v.25 no.6
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    • pp.17-29
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    • 2009
  • There has been an increase in the investigation of deep sea sediments with a consequent increase in the amount of energy required to undertake these investigations. The geotechnical characteristics of Ulleung Basin sediment are explored by using depressurized specimens following methane production tests carried out on pressured core samples obtained at 2,100 m water depth and 110 m below sea floor. Geotechnical index tests, X-ray diffraction, and scanning electron microscope are conducted to identify the geotechnical index parameters, clay mineralogy, chemical composition, and microstructure of the sediments. Compressibility, and elastic and electromagnetic wave parameters are investigated for two samples by using a multi sensing instrumented oedometer cell. The strength chatracteristics are obtained by the direct shear tests. The dominant clay minerals are mostly kaolinite, illite, chlorite, and calcite. The SEM shows a well-developed flocculated structure of the microfossil. Void ratio, electrical resistivity, real permittivity, conductivity, and shear wave velocity show bi-linear behavior with the effective vertical stress: as the vertical effective stress increases. The friction angle obtained by the direct shear test is about $21^{\circ}$, which is similar to the value observed in the Ulleung Basin sediments. This study shows that the understanding of the behavior acting on the diatomaceous marine sediment is important because it often maintains the useful energy resources such as gas hydrate and so will be the new engineering field in the next generation.

Ginsenoside Rg1 treatment protects against cognitive dysfunction via inhibiting PLC-CN-NFAT1 signaling in T2DM mice

  • Xianan Dong ;Liangliang Kong ;Lei Huang ;Yong Su ;Xuewang Li;Liu Yang;Pengmin Ji ;Weiping Li ;Weizu Li
    • Journal of Ginseng Research
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    • v.47 no.3
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    • pp.458-468
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    • 2023
  • Background: As a complication of Type II Diabetes Mellitus (T2DM), the etiology, pathogenesis, and treatment of cognitive dysfunction are still undefined. Recent studies demonstrated that Ginsenoside Rg1 (Rg1) has promising neuroprotective properties, but the effect and mechanism in diabetes-associated cognitive dysfunction (DACD) deserve further investigation. Methods: After establishing the T2DM model with a high-fat diet and STZ intraperitoneal injection, Rg1 was given for 8 weeks. The behavior alterations and neuronal lesions were judged using the open field test (OFT) and Morris water maze (MWM), as well as HE and Nissl staining. The protein or mRNA changes of NOX2, p-PLC, TRPC6, CN, NFAT1, APP, BACE1, NCSTN, and Ab1-42 were investigated by immunoblot, immunofluorescence or qPCR. Commercial kits were used to evaluate the levels of IP3, DAG, and calcium ion (Ca2+) in brain tissues. Results: Rg1 therapy improved memory impairment and neuronal injury, decreased ROS, IP3, and DAG levels to revert Ca2+ overload, downregulated the expressions of p-PLC, TRPC6, CN, and NFAT1 nuclear translocation, and alleviated Aβ deposition in T2DM mice. In addition, Rg1 therapy elevated the expression of PSD95 and SYN in T2DM mice, which in turn improved synaptic dysfunction. Conclusions: Rg1 therapy may improve neuronal injury and DACD via mediating PLC-CN-NFAT1 signal pathway to reduce Aβ generation in T2DM mice.

Availability of the metapopulation theory in research of biological invasion: Focusing on the invasion success (침입생물 연구에 대한 메타개체군 이론의 활용 가능성: 침입 성공을 중심으로)

  • Jaejun Song;Jinsol Hong;Kijong Cho
    • Korean Journal of Environmental Biology
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    • v.40 no.4
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    • pp.525-549
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    • 2022
  • The process of biological invasion is led by the dynamics of a population as a demographic and evolutionary unit. Spatial structure can affect the population dynamics, and it is worth being considered in research on biological invasion which is always accompanied by dispersal. Metapopulation theory is a representative approach to spatially structured populations, which is chiefly applied in the field of ecology and evolutionary biology despite the controversy about its definition. In this study, metapopulation was considered as a spatially structured population that includes at least one subpopulation with significant extinction probability. The early phase of the invasion is suitable to be analyzed in aspects of the metapopulation concept because the introduced population usually has a high extinction probability, and their ecological·genetic traits determining the invasiveness can be affected by the metapopulation structure. Although it is important in the explanation of the prediction of the invasion probability, the metapopulation concept is rarely used in ecological research about biological invasion in Korea. It is expected that applying the metapopulation theory can supply a more detailed investigation of the invasion process at the population level, which is relatively inadequate in Korea. In this study, a framework dividing the invasive metapopulation into long- and middle-distance scales by the relative distance of movement to the natural dispersal range of species is proposed to easily analyze the effect of a metapopulation in real cases. Increased understanding of the mechanisms underlying invasions and improved prediction of future invasion risk are expected with the metapopulation concept and this framework.