• Title/Summary/Keyword: 전파전파특성

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Study of Prediction Model Improvement for Apple Soluble Solids Content Using a Ground-based Hyperspectral Scanner (지상용 초분광 스캐너를 활용한 사과의 당도예측 모델의 성능향상을 위한 연구)

  • Song, Ahram;Jeon, Woohyun;Kim, Yongil
    • Korean Journal of Remote Sensing
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    • v.33 no.5_1
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    • pp.559-570
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    • 2017
  • A partial least squares regression (PLSR) model was developed to map the internal soluble solids content (SSC) of apples using a ground-based hyperspectral scanner that could simultaneously acquire outdoor data and capture images of large quantities of apples. We evaluated the applicability of various preprocessing techniques to construct an optimal prediction model and calculated the optimal band through a variable importance in projection (VIP)score. From the 515 bands of hyperspectral images extracted at wavelengths of 360-1019 nm, 70 reflectance spectra of apples were extracted, and the SSC ($^{\circ}Brix$) was measured using a digital photometer. The optimal prediction model wasselected considering the root-mean-square error of cross-validation (RMSECV), root-mean-square error of prediction (RMSEP) and coefficient of determination of prediction $r_p^2$. As a result, multiplicative scatter correction (MSC)-based preprocessing methods were better than others. For example, when a combination of MSC and standard normal variate (SNV) was used, RMSECV and RMSEP were the lowest at 0.8551 and 0.8561 and $r_c^2$ and $r_p^2$ were the highest at 0.8533 and 0.6546; wavelength ranges of 360-380, 546-690, 760, 915, 931-939, 942, 953, 971, 978, 981, 988, and 992-1019 nm were most influential for SSC determination. The PLSR model with the spectral value of the corresponding region confirmed that the RMSEP decreased to 0.6841 and $r_p^2$ increased to 0.7795 as compared to the values of the entire wavelength band. In this study, we confirmed the feasibility of using a hyperspectral scanner image obtained from outdoors for the SSC measurement of apples. These results indicate that the application of field data and sensors could possibly expand in the future.

Interaction Between Groundwater and Stream Water Induced by the Artificial Weir on the Streambed (하상 인공구조물에 의해 유도되는 지하수-하천수 시스템의 상호작용)

  • Oh, Jun-Ho;Kim, Tae-Hee;Sung, Hyun-Cheong;Kim, Yong-Je;Song, Moo-Young
    • Journal of Soil and Groundwater Environment
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    • v.12 no.2
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    • pp.9-19
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    • 2007
  • This study investigated the interaction between groundwater and stream water systems, which is caused by the artificial weir on streambed, enforcing external stresses on the groundwater system. The study area is in Nami Natural Recreation Woods located in Chungcheongnam-do Geumsan-gun Nami-myeon Geoncheon-ri. In this study both of hydrophysical methods (hydraulic head) and hyrdochemical investigations (pH, EC, major ion analysis) were applied. In order to identify the relationship between each of study results, cross-correlation analysis is performed. From results of hydrophysical methods, water level fluctuation at BH-14, installed by the weir, shows the double-recession pattern much more frequently and much higher amplitudes than the fluctuation at each of other monitoring wells. Using the results by hydrochemical investigations, hydrochemical properties at BH-14 is similar to the hydrochemical characteristics in stream water. To analyze the interrelationships between the results from each of applied methods, cross-correlation analysis was applied. Results from the correlation analyses, water levels at BH-14 and stream weir showed the highest cross-correlation in hydrophysical aspects. On the other hand, the correlation between stream weir and bridge was the highest in hydrochemical aspects. The difference between the results from each of methods is due that the hydrophysical response at BH-14, such as water level, is induced by the pressure propagation-not with mass transfer, but the hydrochemical interaction, caused by mass transport, takes much more times. In conclusion impermeable artificial weir on streambed changes the interfacial condition between the stream and surrounding aquifers. The induced water flux into the groundwater system during flood period make water level at BH-14 increase instantly and groundwater quality higly similar to the quality of stream water. Referred similarities in both of water level and water quality at BH-14 become much higher when water level at weir grow higher.

A Study on a Type of Regeneration Project on Old Industrial Complex (노후산업단지 재생사업 추진 유형에 관한 연구)

  • Kim, Joo-hoon;Byun, Byung-seol
    • Journal of the Economic Geographical Society of Korea
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    • v.21 no.2
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    • pp.192-211
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    • 2018
  • With significant influences of old industrial complex in September 2009, Ministry of Land, Infrastructure and Transport chose the 4 districts for the first pilot project. In December 2014, the second pilot project districts were established. In addition, there were 10 districts in April 2016 and 5 districts in April 2016 as the third pilot project and 5 districts in March 2017 as the fourth pilot project. In order to promote smooth business operation of the recycling business, we introduced the effective area designation and special system as stipulated in Article 39.12-13 of the Industrial Location and Development Act revised in May 2015. The effective area, It is a method that can promote propagation and diffusion of the rehabilitation business through visualization by making effective the promotion of the rehabilitation business and by promoting the business in consideration of the geographical feature of the region and industry group, The setting of the unreasonable effective area is based on the criteria and classification of the plan and the objective promotion method according to the individual characteristics of the aged industrial park because the delay of the rehabilitation business and the possibility of the increase of many problems are presented Be sure to Data Envelopment Analysis (DEA) and the old industrial complex database were constructed and utilized to classify the types of recycling projects. Therefore, in this study, it is necessary to strengthen the competitiveness of aged industrial complex by examining the correlation between the diagnosis of 83 aged industrial complex sites and the rehabilitation projects supported by the Ministry of Land, and the types of business promotion for aged industrial parks. It can be used as a guideline for the feasibility of the project.

An Epidemiologic Study on the Seropositive Rate of Hepatitis A Virus in Children of Gwangju and Jeonnam (광주, 전남 지역 소아의 A형 간염 항체 보유율에 대한 연구)

  • Jung, Ji;Ahn, Young-Joon;Moon, Kyung-Rye
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.14 no.1
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    • pp.67-73
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    • 2011
  • Purpose: Recently, the incidence of acute hepatitis A has increased nationwide and is related to a low rate of IgG anti-HAV production. To establish effective measures for preventing hepatitis A virus infection, an epidemiologic study on the seroprevalence of anti-HAV is needed. Thus, we investigated the seroprevalence of IgG anti-HAV in children living in Gwangju and Jeonnam. Methods: IgG anti-HAV levels were measured in a total of 1,435 patients who visited Chosun University Hospital between January 2009 and December 2009. Results: The overall seropositve rate was 40.8% (586/1,435). The seropositive rates were 41% among children under the age of 1 year, 49.9% for children 1~5 years old, 51.1% among individuals 5~10 years old, 12.9% for individuals 10~15 years old, and 8.2% for subjects over 15 years old. There was no significant difference between genders in any group. The seropositive rates in Gwangju and Jeonnam were 57.3% and 32.9% for children under the age of 1 year, 52.5% and 44.3% for children 1~5 years old, 60.2% and 33.9% among children 5~10 years old, 14.1% and 9.7% for children 10~15 years old, and 10.8% and 4.2% for individuals over 15 years old. Conclusion: The results demonstrated the low rates of IgG anti-HAV, particularly among subjects over 10 years old, which suggests the possibility of increasing clinical HAV infection rates among adults in the near future. We should actively prevent the spread of hepatitis A virus. Vaccination is the most effective means of preventing hepatitis A virus transmission among persons at risk for infection. Hepatitis A vaccination is recommended for children who have low IgG anti-HAV seropositive rates.

Experimental Evaluation of Bi-directionally Unbonded Prestressed Concrete Panel Impact-Resistance Behavior under Impact Loading (충돌하중을 받는 이방향 비부착 프리스트레스트 콘크리트 패널부재의 충돌저항성능에 대한 실험적 거동 평가)

  • Yi, Na-Hyun;Lee, Sang-Won;Lee, Seung-Jae;Kim, Jang-Ho Jay
    • Journal of the Korea Concrete Institute
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    • v.25 no.5
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    • pp.485-496
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    • 2013
  • In recent years, frequent terror or military attacks by explosion or impact accidents have occurred. Examplary case of these attacks were World Trade Center collapse and US Department of Defense Pentagon attack on Sept. 11 of 2001. These attacks of the civil infrastructure have induced numerous casualties and property damage, which raised public concerns and anxiety of potential terrorist attacks. However, a existing design procedure for civil infrastructures do not consider a protective design for extreme loading scenario. Also, the extreme loading researches of prestressed concrete (PSC) member, which widely used for nuclear containment vessel, gas tank, bridges, and tunnel, are insufficient due to experimental limitations of loading characteristics. To protect concrete structures against extreme loading such as explosion and impact with high strain rate, understanding of the effect, characteristic, and propagation mechanism of extreme loadings on structures is needed. Therefore, in this paper, to evaluate the impact resistance capacity and its protective performance of bi-directional unbonded prestressed concrete member, impact tests were carried out on $1400mm{\times}1000mm{\times}300mm$ for reinforced concrete (RC), prestressed concrete without rebar (PS), prestressed concrete with rebar (PSR, general PSC) specimens. According to test site conditions, impact tests were performed with 14 kN impactor with drop height of 10 m, 5 m, 4 m for preliminary tests and 3.5 m for main tests. Also, in this study, the procedure, layout, and measurement system of impact tests were established. The impact resistance capacity was measured using crack patterns, damage rates, measuring value such as displacement, acceleration, and residual structural strength. The results can be used as basic research references for related research areas, which include protective design and impact numerical simulation under impact loading.

Detection of IgY Specific to Salmonella enteritidris and S. typhimurium in the Yolk of Commercial Brand Eggs using ELISA (ELISA 방법으로 계란의 난황에 존재하는 Salmonella enteritidis와 S. typhimurium에 대한 IgY 측정)

  • 이승배
    • Food Science of Animal Resources
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    • v.23 no.2
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    • pp.161-167
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    • 2003
  • Identification of salmonellosis-infected commercial poultry flocks has become a pivotal component of efforts to reduce incidence of egg-associated transmission of S. enteritidis and S. typhimurium to humans. As a basic study for sanitary control of S. enteritidis and S. typhimurium, main food-borne pathogenic bacteria in eggs produced by domestic hens, commercial egg samples were tested for specific antibodies to whole cells of S. enteritidis and S. typhimurium and outer membrane protein(OMP) of S. typhimurium by ELISA to detect infection of S. enteritidis and S. typhimurium in various groups of hens. When the antibody titers of yolks from three commercial brand eggs were tested after diluting in the ratio from 1:100 to 1:1,600 with double dilution method, ELISA values of the specific antibodies could be shown as differences in dilution patterns by comparing with negative control egg. When the antibody titers of the yolks from two commercial brand eggs were tested after diluting in the ratio of 1:200 and 1:1,000, ELISA values of specific antibodies were different among same brand eggs. When the antibody titers of yolks from five eggs sampled randomly from twenty one commercial brand eggs were tested after diluting in the ratio of 1:1,000, ELISA value of the specific antibodies were shown generally high. ELISA values of 28.5, 30, and 28.5% of yolks from 21 brand eggs were shown low and similar to negative control egg in antibody titers to whole cells of S. enteritidis and S. typhimurium and OMP of S. typhimurium, respectively. The results demonstrated that ELISA test of egg yolk antibody could provide a highly sensitive indicator to detect contamination of S. typhimurium and S. enteritidis in poultry, and could be used effectively to reduce incidence of S. typhimurium and S. enteritidis infection in poultry.

Fatigue fracture of different dental implant system under cyclic loading (반복하중에 따른 수종 임플란트의 피로파절에 관한 연구)

  • Park, Won-Ju;Cho, In-Ho
    • The Journal of Korean Academy of Prosthodontics
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    • v.47 no.4
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    • pp.424-434
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    • 2009
  • Statement of problem: Problems such as loosening and fractures of retained screws and fracture of implant fixture have been frequently reported in implant prosthesis. Purpose: Implant has weak mechanical properties against lateral loading compared to vertical occlusal loading, and therefore, stress analysis of implant fixture depending on its material and geometric features is needed. Material and methods: Total 28 of external hexed implants were divided into 7 of 4 groups; Group A (3i, FULL $OSSEOTITE^{(R)}$Implant), Group B (Nobelbiocare, $Br{\aa}nemark$ $System^{(R)}$Mk III Groovy RP), Group C (Neobiotec, $SinusQuick^{TM}$ EB), Group D (Osstem, US-II). The type III gold alloy prostheses were fabricated using adequate UCLA gold abutments. Fixture, abutment screw, and abutment were connected and cross-sectioned vertically. Hardness test was conducted using MXT-$\alpha$. For fatigue fracture test, with MTS 810, the specimens were loaded to the extent of 60-600 N until fracture occurred. The fracture pattern of abutment screw and fixture was observed under scanning electron microscope. A comparative study of stress distribution and fracture area of abutment screw and fixture was carried out through finite element analysis Results: 1. In Vicker's hardness test of abutment screw, the highest value was measured in group A and lowest value was measured in group D. 2. In all implant groups, implant fixture fractures occurred mainly at the 3-4th fixture thread valley where tensile stress was concentrated. When the fatigue life was compared, significant difference was found between the group A, B, C and D (P<.05). 3. The fracture patterns of group B and group D showed complex failure type, a fracture behavior including transverse and longitudinal failure patterns in both fixture and abutment screw. In Group A and C, however, the transverse failure of fixture was only observed. 4. The finite element analysis infers that a fatigue crack started at the fixture surface. Conclusion: The maximum tensile stress was found in the implant fixture at the level of cortical bone. The fatigue fracture occurred when the dead space of implant fixture coincides with jig surface where the maximum tensile stress was generated. To increase implant durability, prevention of surrounding bone resorption is important. However, if the bone resorption progresses to the level of dead space, the frequency of implant fracture would increase. Thus, proper management is needed.

Neotectonic Crustal Deformation and Current Stress Field in the Korean Peninsula and Their Tectonic Implications: A Review (한반도 신기 지각변형과 현생 응력장 그리고 지구조적 의미: 논평)

  • Kim, Min-Cheol;Jung, Soohwan;Yoon, Sangwon;Jeong, Rae-Yoon;Song, Cheol Woo;Son, Moon
    • The Journal of the Petrological Society of Korea
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    • v.25 no.3
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    • pp.169-193
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    • 2016
  • In order to characterize the Neotectonic crustal deformation and current stress field in and around the Korean Peninsula and to interpret their tectonic implications, this paper synthetically analyzes the previous Quaternary fault and focal mechanism solution data and recent geotechnical in-situ stress data and examines the characteristics of crustal deformations and tectonic settings in and around East Asia after the Miocene. Most of the Quaternary fault outcrops in SE Korea occur along major inherited fault zones and show a NS-striking top-to-the-west thrust geometry, indicating that the faults were produced by local reactivation of appropriately oriented preexisting weaknesses under EW-trending pure compressional stress field. The focal mechanism solutions in and around the Korean Peninsula disclose that strike-slip faulting containing some reverse-slip component and reverse-slip faulting are significantly dominant on land and in sea area, respectively. The P-axes are horizontally clustered in ENE-WSW direction, whereas the T-axes are girdle-distributed in NNW direction. The geotechnical in-situ stress data in South Korea also indicate the ENE-trending maximum horizontal stress. The current crustal deformation in the Korean Peninsula is thus characterized by crustal contraction under regional ENE-WSW or E-W compression stress field. Based on the regional stress trajectories in and around East Asia, the current stress regime is interpreted to have resulted from the cooperation of westward shallow subduction of the Pacific Plate and collision of Indian and Eurasian continents, whereas the Philippine Sea plate have not a decisive effect on the stress-regime in the Korean Peninsula due to its high-angle subduction that resulted in dominant crust extension of the back-arc region. It is also interpreted that the Neotectonic crustal deformation and present-day tectonic setting of East Asia commenced with the change of the Pacific Plate motion during 5~3.2 Ma.

Influence of Large-Scale Environments on Tropical Cyclone Activity over the Western North Pacific: A Case Study for 2009 (대규모 순환장이 북서태평양 태풍활동에 끼치는 영향: 2009년의 예)

  • Choi, Woosuk;Ho, Chang-Hoi;Kim, Hyeong-Seog
    • Journal of Climate Change Research
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    • v.1 no.2
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    • pp.133-145
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    • 2010
  • This study examined the characteristics of tropical cyclone(TC) activity over the western North Pacific(WNP) in 2009. Twenty-two TCs formed in 2009, which is slightly below normal(1979~2009 average: 25.8) and most of these occurred during the months of July to October. Most TCs in 2009 was formed over the northern Philippines and the eastern part of the WNP and they moved towards the South China Sea and the east of Japan, resulting in less TC affecting the East China Sea and Korea. The TC activity in 2009 is modulated by the large-scale circulations induced by the El $Ni{\tilde{n}}o$ and vigorous convection activity over the WNP. As the general characteristics of El $Ni{\tilde{n}}o$ year, the difference in sea surface temperature between the central Pacific and the eastern Pacific causes an anomalous westerly winds, expanding the WNP monsoon trough farther eastward. Accordingly, TC formation has relatively increased in the east part of the WNP. Active convection activities over the subtropical western Pacific excite a Rossby wave propagating from the South China Sea to mid-latitudes, resulting in an anomalous easterly steering flow in the South China, anomalous northwesterly over the East China Sea and Korea, and anomalous southwesterly over the east of Japan. Summing up, the TCs cannot enter the East China Sea and Korean region and instead they move towards the South China Sea or south-east of Japan. There were no effects of TCs in Korea in 2009. It is anticipated that this study which analyzed unusual TC activity and large-scale circulations in 2009 would help the predictability of TC effects to increase according to climate change in the East Asia.

The history of awareness for ginseng in Vietnam (베트남의 고려인삼 인식에 대한 소고)

  • Ock, Soonjong
    • Journal of Ginseng Culture
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    • v.1
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    • pp.78-92
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    • 2019
  • Among the Southeast Asian countries, Vietnam had the most cultural exchange with Korea. Through Confusion and Chinese character, which were the common measure for two countries, Korea and Vietnam could communicate and share a sentiment with each other. Two countries showed an enormous interest in each other, and hence they could keep good relationship without official diplomatic relations. During the early 19th century, Korean Ginseng had gained tremendous popularity in Vietnam. Vietnamese believed the stamina of Minh Mang, who had 142 sons and daughters, originated from ginseng. Minh Mang bestowed ginseng on old courtiers for their contribution, which made them more loyal to the king. This tradition was inherited to the future generations, and soldiers who fought with Thai, Cambodia and France also received ginseng for their contribution. In other words, ginseng was the very important key for enforcement of patriotism. Due to the tradition, Korean ginseng has been considered as the premium ginseng in Vietnam. It is presumed that ginseng flew into Vietnam through 4 routes; 1) as an imperial gift from Chinese emperor, 2) by the Vietnamese ambassadors who went to Beijing for a tribute, 3) through private trade and 4) from Ryukyu or Japan, which were the hub of international trade. From 15th to 18th century, ambassadors from Chosun and Vietnam actively interacted in Beijing. Through their interchange, Vietnamese royal family could learn about the value of ginseng. The fact that there were many Shilhak scholars among the ambassadors from Joseon, such as Seo Geojeong and Seo Hosu who had profound knowledge of ginseng proves the theory. It is also possible that reputation of ginseng was already established in Vietnam during Silla period. Ko Byung, an bureaucrat from Tang Dynasty who ruled Vietnam for 10 years in middle 9th century and a friend of Choi Chiwon, might have delivered the knowledge of ginseng to the upper class in Vietnam. This hypothesis, however, should be proven by literatures. Hence, further research about the trace of Korean ginseng in Vietnamese history and literary works still remains to be done.