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        검색결과 282

        81.
        2017.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We measured the target strength according to the swimming tilt angle and size change for Pacific herring at the frequency of 70 kHz as the basic database in order to estimate its abundance as well as density in the survey area using the hydroacoustical method. The number of the sample used in this study was 14 individuals, and its size distribution by fork length ranged between 20.3 and 29.8 cm and wet weight was measured between 187.6 and 269.9 g. The variation of TS according to the swimming angle (-30~30°) was measured between 10.3 and 18.8 dB in frequency range, the highest value was measured at head-down of Pacific herring in the tilt angle range between 5 and 9 deg. of its swimbladder. The relationship between TS–FL of herring was the same as TS = 20log10 (FL) – 66.79 when its swimming tilt angle in the daytime (3.8 ± 6.0°) and nighttime (-3.2 ± 13.6°), respectively.
        4,000원
        82.
        2017.06 구독 인증기관 무료, 개인회원 유료
        Effective estrus detection and artificial insemination (AI) are necessary for profitable management of dairy herd. In current study, 45 crossbred lactating cows have been selected with the complaint of unobserved oestrus for more than sixty days postpartum. All cows had functional corpus luteum as examined by transrectal ultrasonography. Cows were treated with PGF2α analogue and AI was performed with observed oestrus and then single dose of GnRH was administered. Similar synchronization protocol has been repeated after 14 days in cows that did not repose to first treatment. Remaining cows received additional PGF2α after 14 days of second treatment and timed AI was performed following GnRH administration. Among 45 cows, 28.89% showed estrus after first treatment and 78.79% responded to second hormonal intervention. A higher conception rate (88.89% vs 26.66 and 72.72%) was observed in cows after triple administration of PGF2α and timed AI. We noticed a significant differences in body condition score (BCS, 1~5 scale), postpartum period, and daily milk production between cows that either responded of non-responded following first and second hormonal treatment. In addition, there was a significant positive correlation between daily milk production and BCS, age and postpartum days, milk production and estrus/BCS, and milk production/BCS/estrus and conception rate. Depending upon the findings we conclude that hormonal intervention with PGF2α and GnRH enhances postpartum ovarian cyclicity and help decreasing the days open of dairy herd. Therefore, this finding might provide an excellent guideline for target breeding system for profitable dairy herd management.
        4,000원
        83.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 일련의 문자열들 중 하나의 표적을 탐지하는 데 자극 명암대비와 색상이 미치는 영향을 관찰하였다. 실험 1의 각 시행에서는 네 문자로 구성된 RSVP가 제시되고 각 RSVP 화면상의 문자들이 서로 다른 위치를 점유하였 다. RSVP 배열 내에서는 한 위치에 회색 표적 문자가, 나머지 위치에 세 방해자극들이 제시된 표적화면을 제외하고 나머지 RSVP 화면에서 네 흰색 방해자극 문자들이 상응하는 위치에 제시되었다. 고가시성 조건에서는 회색 배경화면 보다 표적 회색이 현저히 어두웠던 반면 저가시성 조건에서는 그 밝기 차이가 상대적으로 분명치 않았다. 참가자들은 사전에 지정된 표적들 중 각 시행에서 어느 것이 출현했는지를 가능한 빠르고 정확하게 탐지하도록 요구받았으며 그 결과 관찰된 탐지 수행은 고가시성 조건에서 더 정확했으며 신속했다. 실험 2에서는 고가시성 조건의 회색 표적을 고선명도 유채색 표적으로 대체한 것을 제외하고 실험 1과 동일한 RSVP 화면 및 과제가 사용되었다. 그 결과 참가자들 은 고가시성 조건의 표적을 더 정확히 탐지했으나 반응 속도에 있어서는 두 가시성 조건 간 차이가 없었다. 두 실험의 결과는 시각적 부담이 높은 상황일지라도 현저한 명암대비 및 색상이 부여될 경우 자극에 대한 지각이 촉진됨을 시사하 며 자극 색상에 비해 명암대비가 지각적 촉진에 더 중요한 역할을 수행할 가능성을 제안한다.
        4,300원
        84.
        2017.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Rockfish was a commercially important fish specie in marine ranching areas in Korea. To estimate density and biomass of rockfish using acoustic method, target strength (TS) information is required on the species. This study measured TS dependence on tilt angle and size on 14 live rockfish individuals at 38, 70, and, 120 kHz by ex-situ measurement (tethered method) and acoustic scattering model (Krichhoff ray mode, KRM). The swimbladdered angle ranged from 18 to 30˚ (mean ± s.d. = 26 ± 4˚ ). The mean TS for all individuals was highest -35.9 dB of tilt angle -17˚ at 38 kHz, -35.4 dB of tilt angle -25˚ at 70 kHz, and -34.9 dB of tilt angle -22˚ at 120 kHz. The ex-situ TS-total length (TL, cm) relationships were TS38kHz = 20log10(TL) - 67.1, TS70kHz = 20log10(TL) - 68.6, and TS120kHz = 20log10(TL) - 69.9, respectively. The model TS-total length (TL, cm) relationships were TS38kHz = 20log10(TL) - 66.4, TS70kHz = 20log10(TL) - 67.0, TS120kHz = 20log10(TL) - 67.0. The two measurements between the ex-situ TS and KRM model for TS-tilt angle and fish size were found to be significantly correlated.
        4,000원
        85.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The identity of toxin producers remains only hypothesis unless there were identified by strain isolation and analytical confirmation of both the cyanotoxin production and the genetic identity of the monoculture. The purposes of this study were to identify a morphologic and phylogenetic classification in Aphanizomenon flos-aquae strains isolated from the Nakdong River and to investigate the potential ability of the strains to produce toxins such as saxitoxin and cylindrospermopsin using target genes. The 16S rRNA and sxtA, sxtI, cyrA, cyrJ genes were analyzed on two strains (DGUC001, DGUC003) isolated from the Nakdong River. Morphological features of the strains were observed a shape of aggregated trichomes in parallel fascicles which can reach up to macroscopic size and a hyaline terminal cell without aerotope. In addition, the 16S rRNA phylogenetic analyses showed that the strains were identified as the same species with high genetic similarity of 98.4% and grouped within a monospecific andsupported cluster I of Aphanizomenon flosaquae selected from GenBank of the NCBI. The cyrA and cyrJ genes encoding for the cylindrospermopsinbiosynthesis were not detected in the present study. The sxtA gene was in detected both the two strains, whereas the sxtI gene which had been suggested as a suitable molecular marker to detect saxitoxin-producing cyanobacteria was not found both the strains. Thus, the two strains isolated from Nakdong River were identified as the same species of Aphanizomenon flos-aquae Ralfs ex Bornet et Flahault 1888, the two strains were confirmed as potential non-producing strains of the saxitoxin and cylindrospermopsin.
        4,200원
        86.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The tail flip of the decapod shrimp is a main feature in escaping behavior from the mesh of the codend in the trawl. The characteristics of tail flip in target prawn was observed and analyzed in a water tunnel in respect of flow condition and mesh penetration by a high speed video camera (500 fps). The tail bending angle or bending time in static water was significantly different than in flow water (0.7 m/s) and resultantly the angular velocity in static water was significantly higher than in flow water when carapace was fixed condition. When escaping through vertical traverse net panel in water flow the relative moving angle and relative passing angle to flow direction during tail flip, it significantly decreases the number of shrimps escaping than the case of blocking shrimp. The bending angles of tail flip between net blocking and passing through mesh were not significantly different while the bending time of shrimp passing through mesh was significantly longer than when shrimp blocking on the net. Accordingly the angular velocity of passing through mesh was significantly slower than blocking on the net although the angular velocity of the tail flip was not significantly related with carapace length. The main feature of tail flip for mesh penetration was considered as smaller diagonal direction as moving and passing angle in relation to net panel as right angle to flow direction rather than the angular velocity of tail flip.
        4,000원
        87.
        2016.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        L2 learners’ target language use has been examined for various purposes, including assessment of the learners’ proficiency and examination of the process of language learning. That is, target language use in the real life tasks on the level as automatized as that of native speakers represents the goal of L2 learning. More importantly, however, target language use has been proposed as a process that provides the learning opportunities, particularly since 1980s by communicative approach to SLA. Until the learners can communicate effortlessly without being conscious of the form of the language, how learners’ attention and awareness are or should be directed to the language form and meaning has been an important issue among the recent SLA theories, summarized as the interface/non-interface debate. This paper discusses how different major SLA theories view learners’ attention and awareness of language form during language use and how it has been measured for both process and result research. Finally, a recent neurobiolobical SLA model is introduced in terms of its methodological and theoretical contribution to SLA research.
        5,500원
        88.
        2016.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We have investigated the properties of thin film transistors(TFT) fabricated using zinc tin oxide(ZTO) thin films deposited via on-axis sputtering and FTS methods. ZTO thin films deposited by FTS showed lower root-mean-square(RMS) roughness and more uniformity than those deposited via on-axis sputtering. We observed enhanced electrical properties of ZTO TFT deposited via FTS. The ZTO films were deposited at room temperature via on-axis sputtering and FTS. The as-deposited ZTO films were annealed at 400 oC. The TFT using the ZTO films deposited via FTS process exhibited a high mobility of 12.91 cm2/V.s, a low swing of 0.80 V/decade, Vth of 5.78 V, and a high Ion/off ratio of 2.52 × 106.
        4,000원
        89.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 조타기 작동 신호에 대하여 AIS 통신을 이용하여 상호 교환함으로써 상대선의 선회정보를 보다 신속히 파악할 수 있는 선회조기감지시스템을 구축하였으며, 이를 실선에 적용하여 해당 시스템의 실효성을 검증하였다. 조타 신호가 조타기를 작동함과 동시에 AIS를 통하여 송신되어 상대선의 ECDIS에 사용된 타각만큼 유색으로 표시되는 것을 확인하였다. 선회조기감지시스템을 통하여 상대선의 변침 상황을 조기에 감지할 수 있었으며, 이를 통한 선박 상호간 충돌회피가 조기에 가능할 것으로 판단된다. 또한, 의심 선박에 대한 VTS의 적극적 관제가 가능하고, 해양안전종합정보시스템을 통한 해양사고 분석에도 활용 가능할 것이다.
        4,000원
        91.
        2016.10 구독 인증기관·개인회원 무료
        Control of the vector mosquitoes is critical for implementation of patient’s decrease. Vector mosquito control has been mainly carried out using pesticides in Republic of Korea (ROK), which has developed the resistance against selected insecticides. Voltage-gated sodium channel (VGSC) and Acethylcholine esterase (AchE) are the target of several classes of insecticides. Genetic mutations of VGSC and AchE have been documented to confer resistances to pyrethroids and organophosphates in mosquitoes, respectively. In our studies, the insecticidal resistable level of An. sinensis from four malaria risk areas near Demilitarized Zone (DMZ) was measured. The partial sequence of An. sinensis voltage gated sodium channel (VGSC) IIS6 domain for Kdr gene and ace1 gene for AchE was sequenced. An. sinensis from two areas demonstrated significantly higher resistance to pyrethroids and mutation rates of Kdr gene were comparatively higher. In all tested areas An. sinensis showed high insecticidal resistance to organophosphates and > 70% of mutation rates of ace1 gene ware higher. Understanding the mechanisms of insecticide resistance among vector mosquitoes populations is very important to efficient and effective vector control.
        92.
        2016.10 구독 인증기관·개인회원 무료
        Non-target predatory insects can be indirectly exposed to aerial pesticide spraying and fogging to control Monochmus beetles that transmit pine wood nematode, Bursaphelenchus xylophilus. We evaluated potential lethal or sublethal effects of thiacloprid on survival and behavior of a carpenter ant species, Camponotus japonicus Mayr. Field-collected ant colonies were directly exposed to several food items, such as thiacloprid-addicted Monochmus beetles, 10% sugar watered cotton balls contaminated by thiacloprid concentrations, and 10% sugar water. Dead beetle bodies caused no apparent adverse effect through dietary exposure in general, although a few ants were died with paralysis at colony level experiment. At individual level, most ant workers were died within 10 days compared to control group. In contrast, dietary exposure of ants to thiacloprid concentrations showed significant lethal effect with paralysis and impaired walking, especially at 10 and 50 mg/L thiacloprid concentrations. Some intoxicated ants recovered within a few days in 10 and 50 mg/L thiacloprid concentrations, but intoxicated ants were generally shown to be less responsible to enemy ants with low aggressive behavior. Implications for predicting hazards of thiacloprid to beneficial arthropods in pine forests are discussed.
        93.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        It is important to select proper ground motions for obtaining accurate results from response history analyses. The purpose of this study is to propose an accurate and efficient method that does not require excessive computation for selecting and scaling ground motions to match target response spectrum mean and variance. The proposed method is conceptually simple and straightforward, and it does not use a simulation algorithm that requires a sophisticated subroutine program. In this method, the desired number of ground motions are sequentially scaled and selected from a ground motion library. The proposed method gives the best selection results using Sum of Square Error and has the smallest value(=0.14). Also, The accuracy and consistency of the proposed method are verified by comparing the selection results of the proposed method with those of existing methods.
        4,000원
        94.
        2016.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문은 생명공학기술을 통해 생산된 LM벼에 대한 비표적 생물체 중 곤충을 중심으로 한 환경위해성 평가방법을 제시하고자 작성하였다. 자료조사를 위해 농업 해충관련 도감 및 서적을 활용하였고 참고문헌과 환경위해성 평가 관련 홈페이지를 참조하였으며, 논문이나 벼와 관련된 서적들을 통해 국내 현황을 참조하였다. 조사결과, 벼에 서식하는 곤충은 약 140여종으로 조사되었고, 초식성 곤충 분류군은 각각 수액섭식자, 곡물섭식자, 잎섭식자, 화분섭식자로 세분화하였다. LM벼에 피해가능성이 큰 비표적 곤충은 12종, 중간인 비표적 곤충은 28종, 경미한 비표적 곤충은 101종으로 조사되었으며, 바이러스를 매개하는 종은 11종, 잠재적 해충으로 분류되는 종은 9종으로 나타났다. 위해가설 가설적립단계 모식도를 작성하기 위하여 LM벼에 악영향을 받기 쉬운 곤충의 지리적 분포, 서식지의 특수화, 확산정도, 종풍부도 등을 이용하여 순위를 매겼으며, 10종(벼총채벌레, 애멸구, 벼멸구, 멸강나방, 혹명나방, 우리가시허리노린재, 먹노린재, 벼멸구붙이, 벼메뚜기, 벼잎굴파리)을 추려내었다. 이후 위해가설 가설정립단계 모식도를 작성하였으며 LM 벼의 비표적 생물에 대한 영향을 추론하였다. 본 논문은 국내 자연생태계의 지속가능한 이용 및 보존에 기여하고, LMO의 환경위해성 평가, 심사를 통해 사전위해성을 차단할 수 있는 방법을 제시하고자 작성되었으며, 결과적으로 국민의 건강 및 생물다양성유지, 자연 생태계 보전을 위한 사후 안전관리 체계구축에 활용될 연구 자료를 제공하고자 한다.
        4,300원
        95.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이중가닥 RNA (double-stranded RNA, dsRNA)는 표적 유전자의 발현을 억제하는 기능으로 해충방제에 응용되었다. 인테그린은 α와 β 단위체로 구성된 이량체 막 단백질이다. 진핵생명체에서 인테그린은 세포-세포 및 세포-세포외기질의 상호연결에 중요한 역할을 담당한다. 인 테그린 β 단위체 발현을 억제하는 특정한 dsRNA (= dsINT)는 해당 곤충에 뚜렷한 치사효과를 유발한다. 또한, dsINT를 발현시키는 형질전환 된 대장균도 해당 곤충에 뚜렷한 살충력을 가진다. 그러나 이 세균 살충제의 야외 적용을 위해서는 제형화 기술이 필요했다. 본 연구는 dsINT를 발현하는 재조합 세균을 동결 건조시켜 대상 곤충에 대해 살충효능을 검정하였다. 동결 건조된 세균은 파밤나방(Spodoptera exigua) 종령 유충에 높은 섭식독을 일으켰다. 파밤나방에 대해서 Bacillus thuringiensis 상용 살충제 처리는 불과 60%의 살충력을 보이는 반면, 동결 건조된 dsINT 발현 세균과 혼합 처리할 때 살충력은 크게 증가하였다. dsINT 발현 세균은 해당 인테그린 염기서열 유사성에 따라 차이를 보이는 해충 종에 선 택적 독성을 나타냈다. 이 결과는 인테그린에 특이적 dsRNA를 발현하는 세균이 동결 건조 제형화 조건하에서도 살충력을 유지한다는 것을 나타 냈다.
        4,000원
        96.
        2016.06 KCI 등재 구독 인증기관·개인회원 무료
        IMF 경제위기 이래로는 우리나라 기업들도 더 이상 적대적 인수합병 으로부터 자유롭지 못해 왔고, 그 결과 우리나라에서도 경영권방어에 대 한 관심이 고조되어 왔다. 하지만 대상회사의 경영진은 적대적 기업인수 시도가 성공하게 되는 경우에 일자리를 잃게 될지 모를 위치에 처해 있 다는 점에서, 대상회사 경영진의 경영권방어에는 - 현실적으로든 또는 잠재적으로든 - 이해충돌(conflicts of interest)의 문제가 수반된다. 그 런 점에서 우리나라 경영권방어 법제는 경영권방어에 내재되어 있는 이 와 같은 이해충돌의 문제를 적확하게 통제해야 한다는 요청에 직면하게 된다. 따라서 본고에서는 적대적 기업인수시도에 직면한 대상회사의 경 영진이 경영권방어로 나아가는 경우에, 대상회사 경영진과 대상회사 또 는 그 주주들 사이의 이해충돌을 적확하게 통제할 수 있는 경영권방어 법제의 정립 방안을 모색해 보았다. 우리나라에서는 대상회사의 경영진이 이용할 수 있는 경영권 방어수단 이 상대적으로 매우 제한적이다. 이는 부분적으로 미국의 포이즌 필 (poison pill)과 같이 경영권방어만을 목적으로 하는 수단이 우리나라에 도입되어 있지 않은데 기인한다. 하지만 우리나라에서 대상회사의 경영 진이 이용할 수 있는 경영권 방어수단이 상대적으로 매우 제한되어 있다 는 점은 특히, 우리 판례에 의한 경영권방어의 과도한 규제현실에서 비 롯된다. 즉, 우리 판례는 경영권방어를 목적으로 신주 등을 제3자에게 배 정하거나 발행하는 것을 무효로 볼 뿐 아니라, 경영권방어를 위해 우리 사주조합에 회사의 자금을 지원해 준 대상회사의 경영진에게 업무상배임 죄의 형사책임을 귀속시킨다. 하지만, 경영권방어에 내재되어 있는 이해충돌의 문제를 적확하게 통 제하기 위해, 우리 경영권방어 법제는 다음과 같이 변모할 필요가 있다. 첫째, ‘경영권방어 목적’을 신주의 제3자 배정 등을 예외적으로 허용하는 상법 제418조 제2항에서 규정하고 있는 ‘경영상 목적’과 언제나 상충하 는 것으로 파악하는 기존의 입장을 지양해야 할 것이다. 뿐만 아니라, 경 영권분쟁 상황에서 우리사주조합에 회사의 자금을 지원해준 대상회상 경 영진에 대한 업무상배임죄의 성립여부를 판단함에 있어, ‘오로지’ 경영권 방어만을 위하여 회사의 자금을 지원해준 경우에만 임무위배성을 인정해 야 할 것이다. 여기서 더 나아가 이러한 경우에도 적대적 기업인수시도가 - 그 인수시도자에 대한 평판이나 인수조건 등을 고려할 때 - 대상회 사나 그 주주들에게 매우 불리한 것이어서 그와 같은 적대적 기업인수시 도를 좌절시킬 필요가 있고, 기업인수시도를 좌절시키게 되면 경영진으로 서 자신의 자리도 보전할 수 있게 되리라는 의사를 가지고 회사의 자금을 지원해 준 경우라면, 불법이득의사를 부정함으로써 업무상배임죄를 귀속시 키지 않는 방향으로 경영권방어 법제는 변모해 나가야 할 것이다.
        97.
        2016.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Tin oxides have been studied for various applications such as gas detecting materials, transparent electrodes, transparent devices, and solar cells. p-type SnO is a promising transparent oxide semiconductor because of its high optical transparency and excellent electrical properties. In this study, we fabricated p-type SnO thin film using rf magnetron sputtering with an SnO/Sn composite target; we examined the effects of various oxygen flow rates on the SnO thin films. We fundamentally investigated the structural, optical, and electrical properties of the p-type SnO thin films utilizing X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV/Vis spectrometry, and Hall Effect measurement. A p-type SnO thin film of PO2 = 3 % was obtained with > 80 % transmittance, carrier concentration of 1.12 × 1018 cm−3, and mobility of 1.18 cm2V− 1s−1. With increasing of the oxygen partial pressure, electrical conductivity transition from p-type to n-type was observed in the SnO crystal structure.
        4,000원
        99.
        2016.04 구독 인증기관·개인회원 무료
        A large number of transgenic crop varieties expressing the Bt (Bacillus thuringiensis) insecticidal proteins have been commercialized in 13 countries since 1996. Although the use of these insect-resistant Bt crops can increase crop quality and yields, concerns remain about the potential negative effects of such crops on ecosystems. Transgenic soybean containing cry1Ac gene have been developed to control Lepidopteran pests of soybean and we aimed to investigate whether this soybean could affect non-target arthropods, which play a major role in ecological functions in agricultural ecosystems. In the present study, we first measured the levels of Cry1Ac protein in Bt soybean at different growth stages of soybean and then we compared the community structure of arthropods occurred in fields of transgenic and wild-type soybean. The levels of Cry1Ac protein in transgenic soybean leaves ranged from 252.9 to 604.5 μg g-1 DW. Multivariate analyses (PerMANOVA and NMDS) showed that the composition of the non-target arthropod community was affected by sampling date but not by soybean genotype. These results suggest that transgenic soybean expressing Cry1Ac protein may not adversely affect such non-target arthropod communities.
        100.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cu-Mn compacts are fabricated by the pulsed current activated sintering method (PCAS) for sputtering target application. For fabricating the compacts, optimized sintering conditions such as the temperature, pulse ratio, pressure, and heating rate are controlled during the sintering process. The final sintering temperature and heating rate required to fabricate the target materials having high density are 700oC and 80oC/min, respectively. The heating directly progresses up to 700oC with a 3 min holding time. The sputtering target materials having high relative density of 100% are fabricated by employing a uniaxial pressure of 60 MPa and a sintering temperature of 700oC without any significant change in the grain size. Also, the shrinkage displacement of the Cu-Mn target materials considerably increases with an increase in the pressure at sintering temperatures up to 700oC.
        4,000원
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