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        검색결과 1,119

        1.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        한반도 남부지역에서 점토대토기문화는 청동기시대 후기에 중국 요령지역으로부터 유입된 문화로 유구와 유물에서 재지의 송국리문화와는 이질적이고 단절된 문화상을 보인다. 그러나 점토대토기문화 에서 확인되는 석기를 송국리문화의 석기군과 비교하면 유사점과 차이점을 모두 보이고 있어‘점토대 토기문화의 석기’에 대한 정체성은 명확하게 정의되지 않고 있다. 본고는 점토대토기문화 유적에서 출토된 석기 전반을 검토하고, 재지문화인 송국리문화와의 비교 분석을 통해 점토대토기문화 석기의 범주와 특징을 살펴보았다. 점토대토기문화의 석기는 송국리문화 에서 보이지 않던 새로운 기종의 출현은 확인되지 않지만, 새로운 형식의 출현은 확인되었다. 이러한 새로운 형식을‘점토대토기문화의 석기’로 설정하였다. 점토대토기문화의 석기상은 세 유형으로 분류하였다. Ⅰ유형은 자체적으로 고안한 형식으로, 무경 식석검, 삼각형석촉, 소형 편평양인석부, 단면 장방형의 석제 방추차 등이 있다. Ⅱ유형은 재지문화의 석기를 독창적으로 변형한 형식으로 구하부 직선의 유구석부, 편평유경촉 등이 있다. Ⅲ유형은 재지 문화의 석기를 그대로 수용한 것으로 합인석부, 편평편인석부, 구하부 사선의 유구석부 등이 있다. 이 세 유형은 점토대토기문화 집단이 새로운 환경에 적응하며 발현된 석기상으로 이를 통해 당시 환경에 적응ㆍ정착하는 과정을 유추할 수 있다. 석기상으로 볼 때, 점토대토기문화는 수렵에 비중을 둔 사회였음을 추정할 수 있다.
        6,300원
        2.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We analyzed the performance of hubless rim propellers based on the number of blades, maintaining a fixed pitch ratio and expanded area ratio, using computational fluid dynamics (CFD). Thrust coefficient, torque coefficient and efficiency according to the number of blades were analyzed. In addition, the pressure distribution on the discharge and suction sides of the blade was analyzed. As the advance ratio increases, the thrust coefficient decreases. The highest thrust was shown when the advance ratio was lowest. For the three, four, five and six-blades, the torque coefficient tended to decrease as the advance ratio increased. In the case of seven and eight-blades, the torque coefficient tended to increase as the advance ratio increased. The maximum efficiency was found when the advance ratio was 0.8. When the three-blade, it showed high efficiency at all advance ratios. A high pressure distribution was observed at the leading edge of the discharge blade, and a low pressure distribution was observed at the trailing edge. Applying a hubless rim-driven thruster with the three-blade can generate higher thrust and increase work efficiency.
        4,000원
        3.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        After the United Nations Convention on the Law of the Sea (UNCLOS) and the United Nations Fish Stocks Agreement (UNFSA) came into effect, international cooperation through Regional Fisheries Management Organizations (RFMOs) was required, and each RFMO established and adopted the Conservation and Management Measure (CMM) for the regional Observer Programs to collect data on fishing activities and biological information and to monitor compliance with its CMMs. The observer coverage required by RFMO is set differently for each organization, ranging from 5% to 100%. In addition, tuna-RFMOs recommend increasing observer coverage in longline fisheries by at least 20% for reliable quantitative analysis of not only target species but also bycatch species and ecologically related species such as sharks, seabirds, sea turtles, and marine mammals. Therefore, in this study, we discussed ways to improve the national observer programs of Korean distant water fisheries that should be addressed in the future to respond to the RFMO trends.
        4,000원
        4.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pharmaceutical products occurring in freshwater bodies create numerous problems for the water bodies owing to their bio-toxic nature. In order to remove such pharmaceutical pollutants, a novel Er-doped Bi4O5Br2/ g-C3N5 nanocomposite was prepared by one-pot synthesis and applied for the photocatalytic removal process. The Er ions doped on the surface of Bi4O5Br2/ g-C3N5 nanocomposite exhibited 97% degradation of tetracycline in 60 min under visible light irradiation, which is higher than pure g-C3N5 and Bi4O5Br2 photocatalysts. The improved photocatalytic properties are attributed to the outstanding visible light harvesting capacity and quick charge carrier separation efficiency which greatly reduced the recombination rate in the heterojunctions. Based on radical trapping experiments, the •O2 −, h+ and •OH radicals played a prominent role in the photodegradation reactions under visible light. Finally, the ternary Er-doped Bi4O5Br2/ g-C3N5 nanocomposite is effectively recyclable with quite a stable photocatalytic removal rate. This work enables a new perspective on the rational design of rare-earth-based nanocomposites for various pharmaceutical pollutants treatment processes.
        4,000원
        5.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        백합 종간 교잡종은 다양한 교배 방법에 의해 생산되어지 고 있다. 그러나 이들 종간 교잡종은 대부분 불임이다. 2n gametes는 백합에서 종간 교잡종 F1의 불임을 극복할 수 있 을 뿐 아니라 우수한 유전형질을 지닌 2n과의 교배에 이용할 수 있고 후대 다양한 유전형질을 기대할 수 있다. 따라서 본 실험에서는 가장 효과적으로 2n gametes를 생산할 수 있는 방법을 구축하기 위하여 백합 Oriental hybrids ‘Medusa’와 ‘Marco Polo’에 N2O를 처리하였다. 같은 Oriental 그룹 내 에서도 ‘Medusa’와 ‘Marco Polo’는 화뢰 크기별 감수분열 시기가 달랐다. 감수분열 tetrad 시기에 염색체를 관찰한 결 과 sequential spindles, tripolar spindles에 의해 2가지 다른 형태가 관찰되었다. ‘Medusa’에서 2atm의 N2O를 처리 한 화뢰 길이 10~15mm와 20~25mm에서 monad, dyad, triad, tetrad가 관찰되었다. 그러나 4atm에서는 tetrad 이외에는 검경 되지 않았다. ‘Marco polo’의 경우 화뢰 길 이 10~15mm, 25~30mm 시기에 2, 4atm의 N2O를 12, 24 시간 동안 처리한 구에서 모두 dyad, triad가 관찰되었다. ‘Medusa’, ‘Marco Polo’ 모두 dyad, triad, tetrad가 관찰 된 시기는 대조구에서 interphase와 metaphase Ⅰ에 해당 하는 시기이다. 화분의 모양은 타원형으로 처리 전·후 변화가 없었으며 처리 후 화분의 크기는 n 보다 큰 화분뿐 아니라 작 은 화분도 관찰되어 전체적으로 다양했다. 화분의 임성과 발 아율은 처리구별로 차이가 없었으나 평균적으로 처리 후가 무처리구보다 임성은 약 10%, 발아는 약 20% 정도 떨어졌다. ‘Medusa’와 ‘Marco Polo’를 이용하여 N2O를 처리한 것과 처리하지 않은 것을 정역 교배하였을 때 자방이 비대 되는 형 태가 2가지이었으나 처리 별 차이는 아니었다. 획득된 식물체 를 Flow cytometry로 검정한 결과, 무처리 ‘Marco Polo’와 2atm 24시간 32mm에 처리한 ‘Medusa’의 교배를 통해 하 나의 식물체에서 2배체와 3배체가 모두 나오는 mixoploid를 확인할 수 있었다. 그 외 실험을 통해 얻은 식물체 중에서 이 수체가 4개 발견되었다. 확실한 3배체를 가진 식물체는 관찰 할 수 없었다.
        4,500원
        6.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to identify the major peacekeeping activities that the Korean armed forces has performed from the past to the present. To do this, we collected 692 press releases from the National Defense Daily over the past 20 years and performed topic modeling and social network analysis. As a result of topic modeling analysis, 112 major keywords and 8 topics were derived, and as a result of examining the Korean armed forces's peacekeeping activities based on the topics, 6 major activities and 2 related matters were identified. The six major activities were 'Northeast Asian defense cooperation', 'multinational force activities', 'civil operations', 'defense diplomacy', 'ceasefire monitoring group', and 'pro-Korean activities', and 'general troop deployment' related to troop deployment in general. Next, social network analysis was performed to examine the relationship between keywords and major keywords related to topic decision, and the keywords ‘overseas’, ‘dispatch’, and ‘high level’ were derived as key words in the network. This study is meaningful in that it first examined the topic of the Korean armed forces's peacekeeping activities over the past 20 years by applying big data techniques based on the National Defense Daily, an unstructured document. In addition, it is expected that the derived topics can be used as a basis for exploring the direction of development of Korea's peacekeeping activities in the future.
        5,100원
        7.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pigs are considered a “mixing vessel” that can produce new influenza strains through genetic reassortments, which threaten public health and cause economic losses worldwide. We performed surveillance of swine influenza virus (SIV) using 114,140 nasal swabs from 11,414 Korean farms from 2009 to 2022, and characterized their genetic evolution at each farm level. A total of 169 farms out of the 11,414 (1.48%) were SIV-positive. The positivity rate for the H1N2 subtype, which is most dominant in the pig population, was 37.87% (64/169). Through hemagglutinin (HA) gene analysis, 64 H1N2-positive farms were classified into Eurasian avian-like (46/64, 71.88%), triple-reassortant (14/64, 21.88%), pdm09 (3/64, 4.69%), and classical swine (1/64, 1.56%) groups. The estimated evolutionary rate of HA in H1N2 from 2009 to 2022 in Korea is 1.5309 × 10-3/site/year (95% HPD intervals from 1.0003 × 10-3 to 2.1735 × 10-3) with an estimated mean growth rate of 0.0114. Estimates of the relative genetic diversity of clades over time suggested that the HA of H1N2 exhibited an increase in population size. The results of this study showed that the Eurasian avian-like-HA of the H1N2 subtype was dominant in the pig population. The continued evolution of the HA of H1N2, which is critical for cell entry, might lead to genetic diversity and the loss of vaccine cross-protection. These results indicate that continus surveillance is imperative for monitoring the evolution of the swine influenza virus.
        4,000원
        8.
        2023.12 구독 인증기관 무료, 개인회원 유료
        This paper attempts to show that the word sì 巳(祀) used after the negative wù 勿 or wú 毋 functions as a “Vintransitive” (all the abbreviations and references used in this paper are given at the end of Part I). As such, it forms a VP, 勿/毋V1V2, where V2 is always one of the six “Type-A ritual Vs”—one being dăo 禱 ‘to pray’, the rest given in the paper. The semantic relationship between V1 (巳/祀) and V2 is closely examined. There are also inscriptions in which V1 is used before yú 于, a “multidirectional” preposition. This is labelled as “Nloc in the sense of ‘in, at’ (not ‘to, for’)” in the construction given in the title. The paper accounts for its motive principle. The paper argues that 巳/祀 is a Vaction meaning “conduct sì-providential ritual”. It was done at a place to seek divine direction and guidance from the deity or Power believed to have dwelt in situ. Originally presented in Takashima (2009a), this paper delves further into linguistic, philological, and cultural aspects of the 巳-ritual couched in the VP, 勿/毋V1(=巳/祀)V2. A major reason for its use is to contrast the 巳-ritual with other rituals and sacrifices. The details will be explained with examples. Part I covers “Examination I: Zhū Shēngyù’s Questions and Zhāng Yùjīn’s Interpretation”. The paper answers the former and evaluates the latter. Part II begins with “Examination II: Qiú Xīguī’s Interpretation” and ends with the conclusions of the entire paper.
        8,600원
        11.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        An eco-friendly material was synthesized through interfacial polymerization of aniline on particles of g-C3N4 with arginine, resulting in Arg-PANI@g-C3N4 composite. The as-synthesized composite was characterized by the Brunauer, Emmett, and Teller (BET) surface area, X-ray energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The adsorption capability of as-synthesized composite towards Orange G (OG) dye has been evaluated under several experimental conditions, such as the adsorbent dosage, initial dye concentration, contact time under agitation, pH of dye solution and temperature. Thermodynamics parameters such as free energy (ΔG°), entropy (ΔS°), and enthalpy (ΔH°) were also calculated and suggested that the adsorption process is spontaneous and endothermic in nature. The kinetics data revealed that the adsorption of OG dye onto Arg-PANI@g-C3N4 follows the pseudo-second order kinetics model. The maximum adsorption capacity was found to be 80.54 mg·g−1. Furthermore, the Arg-PANI@g-C3N4 surface exhibited a Langmuir-like adsorption isotherm in contrast to a Freundlich isotherm due to homogeneous active site distribution. Regeneration investigation showed the excellent reusability of Arg-PANI@g-C3N4 composite during the cleaning up of solution containing OG dye molecules.
        4,300원
        12.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As a promising anode for sodium-ion batteries (SIBs), cobalt sulfide ( CoS2) has attracted extensive attention due to its high theoretical capacity, easy preparation, and superior electrochemical activity. However, its intrinsic low conductivity and large volume expansion result in poor cycling ability. Herein, nitrogen-doped carbon-coated CoS2 nanoparticles (N–C@ CoS2) were prepared by a C3N4 soft-template-assisted method. Carbon coating improves the conductivity and prevents the aggregation of CoS2 nanoparticles. In addition, the C3N4 template provides a porous graphene-like structure as a conductive framework, affording a fast and constant transport path for electrons and void space for buffering the volume change of CoS2 nanoparticles. Benefitting from the superiorities, the Na-storage properties of the N–C@CoS2 electrode are remarkably boosted. The advanced anode delivers a long-term capacity of 376.27 mAh g− 1 at 0.1 A g− 1 after 500 cycles. This method can also apply to preparing other metal sulfide materials for SIBs and provides the relevant experimental basis for the further development of energy storage materials.
        4,000원
        13.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The development of food packaging materials with mechanical and antimicrobial properties is still a major challenge. N, P-doped carbons (NPCs) were synthesized. Poly(butylene adipate-co-terephthalate) (PBAT), which has an adverse effect on the environment and affects petroleum resources, has been commonly used for applications as food packaging. The development of PBAT composites reinforced with NPCs and studies on their structure and antimicrobial properties are presented in this study. The composite materials in the PBAT/NPCs were processed by solution casting. The plasticizing properties of NPCs enhanced the mechanical strength of composites produced of PBAT and NPCs. The thermal properties of PBAT composites were enhanced with addition of NPCs, according to thermogravimetric analysis (TGA). After reinforcement, PBAT/NPCs composites became more hydrophobic, according to contact angle measurements. In studies against S. aureus and E. coli food-borne pathogenic bacteria, the obtained composites show noticeably improved antimicrobial activity. The composite materials, according to the results of PBAT and NPCs may be a good choice for packing for food that prevents microorganisms.
        4,000원
        14.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sulfur and nitrogen co-doped carbon dots (NSCDs) were quickly synthesized by the microwave-assisted method from triammonium citrate and thiourea. NSCDs showed a quantum yield of 11.5% with excitation and emission bands at 355 and 432 nm, respectively. Also, a fluorescence quenching was observed in the presence of Pb(II) ions, and the as-synthesized CDs were used as a sensitive probe for detecting Pb(II) in water and food samples. The results showed the optimal conditions for Pb(II) determination were CDs concentration of 0.02 mg mL− 1 at pH 6.0–7.0 and an incubation time of 20 min. The relative fluorescence intensity of NSCDs was proportional to Pb(II) concentrations in the range of 0.029–2.40 and 2.40–14.4 μmol L− 1 with a correlation coefficient (R2) of 0.998 and 0.955, respectively, and a detection limit of 9.2 × 10– 3 μmol L− 1. Responses were highly repeatable, with a standard deviation below 3.5%. The suggested method demonstrates the potential of a green, fast, and low-cost approach for Pb(II) determination in water, tea, and rice samples with satisfying results.
        4,000원
        15.
        2023.10 구독 인증기관·개인회원 무료
        One of the taxa of the superfamily Gelechioidea, Stathmopodidae, is widely distributed around the world, with 39 genera and 390 species reported as of 2015. This family shares the common characteristic of carrying their long hind tibia, but depending on the species, they have a variety of wing patterns and colors. Additionally, while there are species classified as pests for causing damage to grains and fruits, there are also species that feed on moss, spore of ferns and aphids. Consequently, they exhibit a diverse range of morphological and ecological characteristics. However, due to the lack of research and similarities between species, there is still much confusion in identification and phylogenetic analysis to date. In this current situation, further research intends to resolve the confusion in the phylogenetic sutdy of Stathmopodidae not only through morphological and molecular analysis but also by incorporation the latest technologies.
        16.
        2023.10 구독 인증기관·개인회원 무료
        본 연구는 주변 환경의 차이에 따른 화분매개곤충의 유입 특성을 파악하기 위하여 국립수목원 내 진화속을걷 는정원과 부추속전문전시원에 식재된 울릉산마늘의 화분매개곤충을 조사하였다. 2023년 5월 22일부터 6월 2일 까지 꽃이 70% 이상 개화하였을 때 포충망을 활용하여 8일간 곤충을 채집하였고, 각 전시원 별 식생(피도), 기후 (온도·습도·조도)를 조사하였다. 조사 결과 진화속을걷는정원에서 피도 60% 온도 26.4℃, 습도 31.5%, 조도 40953.6lx, 화분매개곤충 20과 450개체, 부추속전문전시원은 피도 90%, 온도 25.6℃, 습도 31.6%, 조도 6387lx, 화분매개곤충 15과 196개체로 나타났다. 온도와 조도가 상대적으로 높은 진화속을걷는정원이 채집된 곤충의 다양성과 방문 빈도가 높았다. 시간대별 곤충의 방문 빈도를 비교해본 결과 온도와 조도는 개체수가 증가할 때 같이 증가하는 경향을 보였으며, 습도는 반대의 경향을 보였다.
        17.
        2023.10 구독 인증기관·개인회원 무료
        최근 기후변화에 따라 아열대 작물 재배가 증가하면서 경남지역 망고 재배면적도 크게 증가하고 있다. 하지만 망고에 발생하는 병해충 발생 정보가 부족하여 2022년부터 현재까지 경남지역에 있는 망고농장을 조사하였으 며, 그 결과 병해 6종, 해충 8종 발생을 확인하였다. 특히 경남지역 망고 포장에서 꽃노랑총채벌레, 대만총채벌레, 볼록총채벌레 등의 발생을 확인하였고, 통영, 함안, 밀양 등에서 총채벌레류에 의한 피해가 발생하였다. 많은 농가에서 총채벌레류 방제를 위해 화학농약에 의존하고 있으나 총채벌레는 반복적인 약제 노출시 빠른 세대 진전으로 인해 저항성 발달이 쉽기때문에 방제에 어려움을 겪고 있다. 이러한 문제를 해결하고자 색상별 끈끈이 트랩의 총채벌레류 유인효과를 확인하였으며, 꽃노랑총채벌레는 노랑, 주황, 연두, 대만총채벌레는 빨강, 노랑, 파랑, 볼록총채벌레는 파랑, 노랑, 빨강 순으로 유인효과가 높은 것을 확인하였다.
        18.
        2023.10 구독 인증기관·개인회원 무료
        Pine Wilt Disease (PWD) is a disease causing mass deaths of pine trees in South Korea, and the dead trees serve as breeding grounds for insect vectors responsible for spreading the disease to other host trees. Because the PWD requires early monitoring to minimize its damage on domestic forestry, this study aims to develop a species distribution model for predicting the potential distribution of PWD by using artificial neural network (ANN) with time-series data. Among the architectures, the Convolutional Neural Network exhibited the highest performance, achieving a validation accuracy of 0.854 and a cross-entropy loss of 0.401, and the InceptionTime model emerged as the second-best performer. This study identified the best-performing ANN architecture for a spatiotemporal evaluation of PWD occurrence, emphasizing the importance for determining hyperparameters with ecological characteristics and data types to apply deep learning into SDMs.
        19.
        2023.10 구독 인증기관·개인회원 무료
        The family Asilidae(robber flies) is one of the representative predatory flies that hunts a variety of insects during the larval and adult stages. There are more than 7,500 known species distributed around the world, and 74 species in 30 genera are recorded in Korea. There are about 270 species of the genus Leptogaster recorded worldwide, and three species (L. augusta, L. basilaris, L. dorsopicta) are recorded in Korea. Through this study, three unrecorded species (L. abdominalis, L. furculata, L. spadix) were identified, and a total of six species were confirmed to be distributed in Korea. We would like to provide general information of the genus Leptogaster, a list of currently distributed species in Korea, photos, diagnostic traits, and so on.
        20.
        2023.10 구독 인증기관·개인회원 무료
        장수풍뎅이(Trypoxylus dichotomus)는 오래 전부터 애완·학습용으로 활용되는 정서곤충으로 곤충산업의 씨 앗이 되는 중요한 곤충이다. 2012년 청원군에서 처음 장수풍뎅이 유충이 일제히 사망한 사례가 있고 2014년부터 비슷한 증상의 사례가 전국적으로 발생했다. 2015년에는 이러한 원인이 장수풍뎅이 누디바이러스(Oryctes rhinoceros nudivirus, OrNV)로 인한 것임이 밝혀졌고 2017년에 raw sequencing data가 NCBI에 공개되었지만 추가 분석은 이루어지지 않았다. 따라서, 우리는 국내 장수풍뎅이에서 분리한 누디바이러스(Trypoxylus dichotomus nudivirus, TdNV-KR)로 명명하고, NCBI로부터 수집한 Malaysia, Solomon Islands, Indonesia, Philippines, Palau strain의 OrNV sequence와 비교 분석하였다. 그 결과, TdNV-KR의 genome size는 126,408bp임을 확인하였고 다른 OrNV strain이 비해 가장 적은 open reading frames(ORF)를 가지고 있었으며, 3개의 ORF가 TdNV genome에서만 부재함을 확인했다. 또한, Nudivirus core genes의 아미노산 염기서열 비교에서는 Single-nucleotide polymorphism 과 indels(insertion/deletion)로 인해 highly conserved 한 OrNV strain의 sequence들에 비해 TdNV의 시퀀스는 많은 변이/차이를 보였다. 우리의 연구는 누디바이러스의 종간 전파에 대한 이해도를 높이고, 바이러스 간의 유연관계 를 확인함으로써 유입 경로를 추정하여 산업곤충의 질병을 효과적으로 예방하는 데 기여할 것이다.
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