• Title/Summary/Keyword: period analysis

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Analysis of Determinants of Carbon Emissions Considering the Electricity Trade Situation of Connected Countries and the Introduction of the Carbon Emission Trading System in Europe (유럽 내 탄소배출권거래제 도입에 따른 연결계통국가들의 전력교역 상황을 고려한 탄소배출량 결정요인분석)

  • Yoon, Kyungsoo;Hong, Won Jun
    • Environmental and Resource Economics Review
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    • v.31 no.2
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    • pp.165-204
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    • 2022
  • This study organized data from 2000 to 2014 for 20 grid-connected countries in Europe and analyzed the determinants of carbon emissions through the panel GLS method considering the problem of heteroscedasticity and autocorrelation. At the same time, the effect of introducing ETS was considered by dividing the sample period as of 2005 when the European emission trading system was introduced. Carbon emissions from individual countries were used as dependent variables, and proportion of generation by each source, power self-sufficiency ratio of neighboring countries, power production from resource-holding countries, concentration of power sources, total energy consumption per capita in the industrial sector, tax of electricity, net electricity export per capita, and size of national territory per capita. According to the estimation results, the proportion of nuclear power and renewable energy generation, concentration of power sources, and size of the national territory area per capita had a negative (-) effect on carbon emissions both before and after 2005. On the other hand, the proportion of coal power generation, the power supply and demand rate of neighboring countries, the power production of resource-holding countries, and the total energy consumption per capita in the industrial sector were found to have a positive (+) effect on carbon emissions. In addition, the proportion of gas generation had a negative (-) effect on carbon emissions, and tax of electricity were found to have a positive (+) effect. However, all of these were only significant before 2005. It was found that net electricity export per capita had a negative (-) effect on carbon emissions only after 2005. The results of this study suggest macroscopic strategies to reduce carbon emissions to green growth, suggesting mid- to long-term power mix optimization measures considering the electricity trade market and their role.

An Empirical Study on the Improvement of In Situ Soil Remediation Using Plasma Blasting, Pneumatic Fracturing and Vacuum Suction (플라즈마 블라스팅, 공압파쇄, 진공추출이 활용된 지중 토양정화공법의 정화 개선 효과에 대한 실증연구)

  • Jae-Yong Song;Geun-Chun Lee;Cha-Won Kang;Eun-Sup Kim;Hyun-Shic Jang;Bo-An Jang;Yu-Chul Park
    • The Journal of Engineering Geology
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    • v.33 no.1
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    • pp.85-103
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    • 2023
  • The in-situ remediation of a solidified stratum containing a large amount of fine-texture material like clay or organic matter in contaminated soil faces limitations such as increased remediation cost resulting from decreased purification efficiency. Even if the soil conditions are good, remediation generally requires a long time to complete because of non-uniform soil properties and low permeability. This study assessed the remediation effect and evaluated the field applicability of a methodology that combines pneumatic fracturing, vacuum extraction, and plasma blasting (the PPV method) to improve the limitations facing existing underground remediation methods. For comparison, underground remediation was performed over 80 days using the experimental PPV method and chemical oxidation (the control method). The control group showed no decrease in the degree of contamination due to the poor delivery of the soil remediation agent, whereas the PPV method clearly reduced the degree of contamination during the remediation period. Remediation effect, as assessed by the reduction of the highest TPH (Total Petroleum Hydrocarbons) concentration by distance from the injection well, was uncleared in the control group, whereas the PPV method showed a remediation effect of 62.6% within a 1 m radius of the injection well radius, 90.1% within 1.1~2.0 m, and 92.1% within 2.1~3.0 m. When evaluating the remediation efficiency by considering the average rate of TPH concentration reduction by distance from the injection well, the control group was not clear; in contrast, the PPV method showed 53.6% remediation effect within 1 m of the injection well, 82.4% within 1.1~2.0 m, and 68.7% within 2.1~3.0 m. Both ways of considering purification efficiency (based on changes in TPH maximum and average contamination concentration) found the PPV method to increase the remediation effect by 149.0~184.8% compared with the control group; its average increase in remediation effect was ~167%. The time taken to reduce contamination by 80% of the initial concentration was evaluated by deriving a correlation equation through analysis of the TPH concentration: the PPV method could reduce the purification time by 184.4% compared with chemical oxidation. However, the present evaluation of a single site cannot be equally applied to all strata, so additional research is necessary to explore more clearly the proposed method's effect.

Clinical Characteristics of Pediatric Patients With the Coronavirus Disease 2019 During the Third and Fourth Waves of the Epidemic in Korea: A Single Center Retrospective Study (국내 코로나바이러스감염증-19 유행 제3-4기 소아청소년 환자의 임상적 특성: 단일기관 후향적 연구)

  • Gawon Moon;Donghyun Shin;Soo-Han Choi
    • Pediatric Infection and Vaccine
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    • v.29 no.3
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    • pp.131-140
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    • 2022
  • Purpose: Since the coronavirus disease 2019 (COVID-19) pandemic began, new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have emerged, and distinct epidemic waves of COVID-19 have occurred for an extended period. This study aimed to analyze the clinical and epidemiological characteristics of children with COVID-19 from the third wave to the middle of the fourth epidemic wave in Korea. Methods: We retrospectively reviewed the medical records of hospitalized patients aged ≤18 years with laboratory-confirmed COVID-19. The study periods were divided into the third wave (from November 13, 2020 to July 6, 2021) and the fourth wave (from July 7 to October 31, 2021). Results: Ninety-three patients were included in the analysis (33 in the third and 60 in the fourth waves). Compared with the third wave, the median age of patients was significantly older during the fourth wave (6.7 vs. 2.8 years, P=0.014). Household contacts was reported in 60.2% of total patients, similar in both periods (69.7 vs. 55.0%, P=0.190). Eighty-one (87.1%) had symptomatic SARS-CoV-2 infection. Among these, 10 (12.3%) had no respiratory symptoms. Anosmia or ageusia were more commonly observed in the fourth epidemic wave (10.7 vs. 34.0%, P=0.032). Most respiratory illness were upper respiratory tract infections (94.4%, 67/71), 4 had pneumonia. The median cycle threshold values (detection threshold, 40) for RNA-dependent RNA polymerase (RdRp) and envelope (E) genes of SARS-CoV-2 were 21.3 and 19.3, respectively. There was no significant difference in viral load during 2 epidemic waves. Conclusions: There were different characteristics during the two epidemic waves of COVID-19.

Comparative Analysis of Cold Tolerance and Overwintering Site of Two Flower Thrips, Frankliniella occidentalis and F. intonsa (꽃노랑총채벌레와 대만총채벌레의 내한성과 월동처 비교 연구)

  • Chulyoung, Kim;Du-yeol, Choi;Falguni, Khan;Md Tafim Hossain, Hrithik;Jooan, Hong;Yonggyun, Kim
    • Korean journal of applied entomology
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    • v.61 no.3
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    • pp.409-422
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    • 2022
  • Two dominant thrips in hot pepper (Capsicum annuum) cultivating in greenhouses are Frankliniella occidentalis and F. intonsa in Korea. This study investigated their overwintering physiology. These two thrips were freeze-susceptible and suppressed the body freezing temperature by lowering supercooling point (SCP) down to -15~-27℃. However, these SCPs varied among species and developmental stages. SCPs of F. occidentalis were -25.7±0.5℃ for adults, -17.2±0.3℃ for pupae, and -15.0±0.4℃ for larvae. SCPs of F. intonsa were -24.0±1.0℃ for adults, -27.0±0.5℃ for pupae, -17.2±0.8℃ for larvae. Cold injuries of both species occurred at low temperature treatments above SCPs. Thrips mortality increased as the treatment temperature decreased and its exposure period increased. F. occidentalis exhibited higher cold tolerance than F. intonsa. In both species, adults were more cold-tolerant than larvae. Two thrips species exhibited a rapid cold hardening because a pre-exposure to 0℃ for 2 h significantly enhanced the cold tolerance to a lethal cold temperature treatment at -10℃ for 2 h. In addition, a sequential exposure of the thrips to decreasing temperatures made them to be acclimated to low temperatures. To investigate the overwintering sites of the two species, winter monitoring of the thrips was performed at the greenhouses. During winter season (November~February), adults of the two species were not captured in outside of the greenhouses. However, F. occidentalis adults were captured to the traps and observed in weeds within the greenhouses. F. occidentalis adults were also emerged from soil samples obtained from the greenhouses during the winter season. F. intonsa adults did not come out from the soil samples at November and December, but emerged from the soil samples obtained after January. To determine the adult emergence due to diapause development, two thrips species were reared under different photoperiods. Adult development occurred in all photoperiod treatments in F. occidentalis, but did not in F. intonsa especially under short periods. Tomato spotted wilt virus, which is transmitted by these two species, was detected in the weeds infested by the thrips during the winter season. These results suggest that F. occidentalis develops on weeds in the greenhouses while F. intonsa undergoes a diapause in the soil during winter.

Analysis of Climate, Weather, Solar Radiation and Solar Energy in Major Cities of Tajikistan (타지키스탄 주요 도시의 기후, 날씨, 일사량 및 태양에너지 분석)

  • Taeyoo Na;Jeongdu Noh;Hyeontae Kim;Seong-Seung Kang
    • The Journal of Engineering Geology
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    • v.33 no.3
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    • pp.389-401
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    • 2023
  • Climate, weather, insolation (solar radiation), and solar energy in major cities of Tajikistan were investigated prior to construction of infrastructure for the Dushanbe Solar Station. In Dushanbe city there was a 70% probability of sunny days from May 16 to October 23, a period of 5.2 months. August had the most sunny days of in the year, with 99% probability of a sunny, the cloudiest month was February with a 41% chance of being sunny. In major cities of the Sughd and Gorno-Badakhshan states, the average number of cloudy days per month was ~3.3, with Dzhauz having 53 day and Fedchnko Glacier 79 days. For the 18 major cities of Tajikistan, the average annual total solar radiation was 2,429 W/m2, and the average monthly solar radiation was 202 W/m2. The city with the lowest annual total and monthly average solar radiation was Shartuz in Sughd state, with values ~2.7% less than the national average. The cities with the highest annual total and monthly average solar radiation were Khorog and Jirgatol in Gorno-Badakhshan state, with values ~10% above the national average. The daily average incident shortwave solar energy in the cities Dushanbe, Karakul, and Jirgatol was ~7.8 kWh per 2.4 m2 during summer (May-August), and 2.7 kWh during winter (November-February), or ~35% that of summer.

Phytoplankton Variability in Response to Glacier Retreat in Marian Cove, King George Island, Antarctica in 2021-2022 Summer (하계 마리안 소만 빙하후퇴에 따른 식물플랑크톤 변동성 분석)

  • Chorom Shim;Jun-Oh Min;Boyeon Lee;Seo-Yeon Hong;Sun-Yong Ha
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.5
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    • pp.417-426
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    • 2023
  • Rapid climate change has resulted in glacial retreat and increased meltwater inputs in the Antarctic Peninsula, including King George Island where Marian Cove is located. Consequently, these phenomena are expected to induce changes in the water column light properties, which in turn will affect phytoplankton communities. To comprehend the effects of glacial retreat on the marine ecosystem in Marian Cove, we investigated on phytoplankton biomass (chlorophyll-a, chl-a) and various environment parameters in this area in December 2021 and January 2022. The average temperature at the euphotic depth in January 2022 (1.41 ± 0.13 ℃) was higher than that in December 2021 (0.87 ± 0.17 ℃). Contrastingly, the average salinity was lower in January 2022 (33.9 ± 0.10 psu) than in December 2021 (34.1 ± 0.12 psu). Major nutrients, including dissolved inorganic nitrogen, phosphate, and silicate, were sufficiently high, and thus, did not act as limiting factors for phytoplankton biomass. In December 2021 and January 2022, the mean chl-a concentrations were 1.03 ± 0.64 and 0.66 ± 0.15㎍ L-1, respectively. The mean concentration of suspended particulate matter (SPM) was 24.9 ± 3.54 mgL-1 during the study period, with elevated values observed in the vicinity of the inner glacier. However, relative lower chl-a concentrations were observed near the inner glacier, possibly due to high SPM load from the glacier, resulting in reduced light attenuation by SPM shading. Furthermore, the proportion of nanophytoplankton exceeded 70% in the inner cove, contributing to elevated mean fractions of nanophytoplankton in the glacier retreat marine ecosystem. Overall, our study indicated that freshwater and SPM inputs from glacial meltwater may possibly act as main factors controlling the dynamics of phytoplankton communities in glacier retreat areas. The findings may also serve as fundamental data for better understanding the carbon cycle in Marian Cove.

A Comparative Study on Daesoon (大巡) Thought and Dangun (檀君) Thought: Focused on the Analysis of Narrative Structure and Motifs (대순사상과 단군사상 비교연구 - 서사구조와 모티프 분석을 중심으로 -)

  • Cha, Seon-keun
    • Journal of the Daesoon Academy of Sciences
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    • v.31
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    • pp.199-235
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    • 2018
  • Most of the new religions derived from Jeungsan have claimed that Jeungsan's religious thought reproduced Dangun [檀君] Thought in its original form. However, Daesoon Jinrihoe is the only religious order out of the many new religions within the Jeungsan lineage, which has constantly kept its distance from Dangun Thought since 1909 during the earliest period of proto-Daesoon Jinrihoe. Even a mere trace of Dangun cannot be found in the subject of faith or the doctrinal system of Daesoon Jinrihoe. In this context, this study aims to examine possible connections between Daesoon Thought and Dangun Thought in order to determine why other Jeungsanist religions frequently exhibit Dangunist features. Specifically, a major part of this study will be devoted to comparing and analyzing the narrative structure of Daesoon Thought and Dangun Thought as well as their respective motifs. In fact, Jeungsan does not seem to have ever mentioned Dangun in his recorded teachings, therefore, after his passing into the Heaven, most of the religious orders including Daesoon Jinrihoe derived from him did not pay any attention to Dangun Thought for almost for 40 years. These orders did not originally perceive Dangun as an object of belief. After Korea's liberation, Dangun became widely accepted as a pivotal role among the Korean people. As Dangun-nationalism claimed to unify Koreans as one great Korean ethnic society, the religious orders of Jeungsan lineage also climbed aboard this creed and their faiths or doctrines were acculturated to reflect this change. The reason for this has been attributed to following modern trends to increase success in propagation. In the meantime, Daesoon Jinrihoe was the only order that did not accept Dangun-nationalism because it was not a teaching given by the order's founder. And the two systems of thought have more dissimilarity than parallelism in terms of philosophical ideology. These seem to be the main reasons why Daesoon Jinrihoe did not adopt Dangun into its doctrine or belief system.

Haewon-sangsaeng Thought for the Future of Humanity and World (인간과 세계의 미래에 관한 해원상생사상 연구)

  • Bae, Kyu-han
    • Journal of the Daesoon Academy of Sciences
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    • v.30
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    • pp.1-57
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    • 2018
  • There are three purposes to this study: first, to understand comprehensively the meaning of Haewon-sangsaeng (Resolution of Grievances for Mutual Beneficence) Thought, which can be taken as representative thought regarding peace in Korean new religions. Next, Haewon-sangsaeng Thought and the works for Haewon (resolving grievances) will be examined as principles and practical mechanisms for building the paradise of the Later World and understanding the structure of this system of thought. Lastly, logical inferences will be made regarding the future of humanity and the world through the ideological characteristics implied by Haewon-sangsaeng Thought. Haewon-sangsaeng Thought contains the complicated concepts of Haewon and Sangsaeng. Haewon is the resolution of the enmity and grievances that have accumulated in the realms of humanity and deities. Sangsaeng indicates the action of mutually benefiting one another or a state wherein people live in prosperity and peace. In Daesoon Jinrihoe, the concept of Haewon-sangsaeng is expressed explicitly and has broad applications. It can be expanded for the global peace and the harmony of all humanity. As the result of an integrated analysis of previous studies, it can be stated that Haewon-sangsaeng has values and meanings in terms of principles, laws, ethics, and ideology all of which are commonly connected to Injon (Human Nobility), Sangsaeng, peace, harmony, the Later World, and paradise. This indicates that its valuable for the future of humanity and world is deeper and wider than its mere etymological meaning. The common factor among paired ideas such as human nobility and Sangsaeng, peace and harmony, and Later World and paradise is the realization of humanity's greatest wish. This is the reason why the value and meaning of Haewon-sangsaeng can be expanded globally. The works of Haewon were a religious act of Kang Jeungsan who resolved the grievances of the Former World which was under the rule of mutual conflict and built a Later World that will operate according to mutual beneficence. Therefore, the principle of Haewon-sangsaeng has a motivative power, through the Reordering Works of the Universe, which can transform the future of humanity and the world. In this study, it can be inferred that as Haewon-sangsaeng 'fulfills human desires' and forms a 'harmonious relations of Sangsaeng' between humans and world, humans will be transformed into Injon (Human Nobility) while the world turns into a paradise, and the future turns into period of peace. Therefore, Haewon-sangsaeng Thought works as a principle that changes society, the world, and the universe. The social actualization of Haewon-sangsaeng is tantamount to bringing the future of Injon, paradise, and peace into objective reality. Previous studies on Haewon-sangsaeng Thought had been carried out under difficult circumstances by a small number of scholars. For all the above reasons, I anticipate that there will be more and more studies made on the topic of Haewon-sangsaeng Thought, which seeks the realization of Haewon (the Resolution of Grievances), Sangsaeng (Mutual Beneficence), human nobility, paradise, and peace. I hope it will emerge as a main subject in global religious thought.

Distribution characteristics of macroinvertebrates in an agricultural paddy field and irrigation pond ecosystems in a farmer's practice manual on the village of the Agricultural Environment Conservation Program (농업 환경보전 프로그램 대상마을의 논과 둠벙 생태계의 저서성대형무척추동물 분포 특성)

  • I-Chan Shin;Seung-Hyun Lee;Young-Mi Lee;Ji-Young Yoon;Sung-Jun Hong;Hyun-Jo Yoon;Sang-Goo Park;Eun-Jung Han
    • Korean Journal of Environmental Biology
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    • v.40 no.2
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    • pp.148-156
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    • 2022
  • Ecological occupation in irrigation ponds is a well-acknowledged fact that is essential for biodiversity conservation in agricultural ecosystems. However, there are few studies on the ecological functions and relationship between a paddy field and irrigation using macroinvertebrates in an environmentally friendly paddy field. The objective of this study is to identify the community and distribution characteristics of macroinvertebrates in an agricultural paddy field and irrigation pond ecosystems, and to provide basic data on the ecological function of an environmentally friendly paddy field. Macroinvertebrate sampling was conducted from May to September in an agricultural paddy field and irrigation pond in an environment-friendly paddy field in Boryeong city. We conducted a study to identify the distribution characteristics using macroinvertebrate species analysis, such as Functional Feeding Groups (FFGs), Habitat Oriented Groups (HOGs), rarefaction curve, and a two-way dendrogram. A total of 37 species of macroinvertebrates in 28 families, 13 orders were collected study during the period of the investigation. Dominant taxa of macroinvertebrates included Coleoptera, Hemiptera, and Odonata. In terms of FFGs, predators and gathering collectors accounted for approximately 70%, in relation to HOGs, and climbers and swimmers occupied more than 50% from both the paddy field and irrigation pond. With respect to the rarefaction curve, the irrigation pond (July) was high as E (S, 141)=18 species, while the paddy field (May) was comparatively low as E (S, 141)=9 species. In conclusion, our results revealed that macroinvertebrates, such as Notonecta triguttata, Peltodytes intermedius, Appasus major, Laccotrephes japonensis, Appasus japonicus, Sigara substriata, Enochrus simulans, and Sternolophus rufipes, were used as a habitat and spawning ground in both paddy field and irrigation pond. The irrigation pond appears to be a very important spawning ground for macroinvertebrates.

First report of Telenomus remus Nixon(Scelionidae), an egg parasitoid of Spodoptera frugiperda(J.E. Smith)(Noctuidae) in Korea and its biological characteristics (한국에서 열대거세미나방 알기생벌 Telenomus remus Nixon (가칭: 밤나방검정알벌)[검정알벌과]의 첫 보고 및 생물적 특성 연구)

  • Jum Rae Cho;Bo Yoon Seo;June Yeol Choi;Gwan Seok Lee;Meeja Seo;Jeong Hwan Kim
    • Korean Journal of Environmental Biology
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    • v.40 no.2
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    • pp.187-198
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    • 2022
  • In this study, Telenomus remus Nixon (Hymenoptera: Scelionidae) was first reported as a natural enemy of the fall armyworm Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) egg collected from corn fields in Korea, and its biological characteristics was studied. Based on morphological and molecular analysis, the parasitoid emerged from S. frugiperda eggs was identified as T. remus. We found that T. remus can attack the eggs of S. frugiperda, Spodoptera litra and Spodoptera exigua under a laboratory condition. The longevity of T. remus female adult was longer than that of male adult. The egg-to-adult period of T. remus was not affected by the host age and sex. T. remus female adult laid at least 1-3 eggs a day to a maximum of 37 or more eggs, and the most oviposited on the 3rd to 4th day after emergence. The host preference for oviposition of T. remus adult was high in the order of S. litura>S. exigua>S. frugiperda. T. remus preferred to parasitize 1- and 2-day-old host egg rather than 3-day-old host egg. When compared to the sex ratio of T. remus progeny, the rate of female progeny was higher at the initiation time of oviposition, while the proportion of male progeny increased significantly with female adult age, especially after 8-day-old adult. This information may be useful for improving T. remus mass rearing system and developing a biological control program to control S. frugiperda.