• 한국통신학회논문지
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• 제28권10B호
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• pp.957-964
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• 2003

정보 통신 하부구조의 빠른 팽창으로 인하여 음란 및 난폭한 정보와 같은 불건전 정보의 유통이 점차적으로 증대하고 있다. 이러한. 정보는 청소년들에게 해로울 뿐만 아니라 사회적 문제를 야기하기 때문에 능동적인 대책이 요구된다. 불건전 정보의 확산에 대처하기 위하여, 정보 통신 관련 법규를 확립 혹은 개정함으로써 적절한 규제 방법이 절실히 요구된다. 본 논문에서는, 기존 유해 정보 차단 방법을 가진 국내외 프로그램을 분석하고 인터넷 내용 등급 서비스를 기반으로 하는 선별 차단 기술을 사용하는 인터넷 내용 선별 플랫폼 기반 선별 차단 프로그램을 설계 및 구현하였다. 또한 연령과 보편화된 차단 목록에 의한 선별 기능을 가진 절충식 등급제 차단 방안을 제안한다. 이 방안은 차단 목록 갱신 및 조회에 따른 네트워크 부하 증가와 같은 문제가 없고, 사용자의 연령을 고려한 능동적인 선별이 가능하며, 자율 등급을 유도할 수 있는 장점을 갖는다.

• International Journal of Control, Automation, and Systems
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• 제2권1호
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• pp.23-38
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• 2004

We proposed the infinity control principle to evaluate the Biological function. The H infinity control was applied to the Sodium (Na) ion selective gating channel on the excitable cellular membrane of the neural system. The channel opening, closing and inactivation processes were expressed by movements of three gates and one inactivation blocking particle in the channel pore. The rate constants of the channel state transition were set to be voltage dependent. The temporal changes in amounts per unit membrane area of the channel states were expressed by means of eight differential equations. The biochemical mimetic used to complete the Na ion selective channel was regarded as noise. The control inputs for ejecting the blocking particle with plugging in the channel pore were set for the active transition from inactivated states to a closed or open state. By applying the H infinity control, we computed temporal changes in the channel states, observers, control inputs and the worst case noises. The present paper will be available for evaluating the noise filtering function of the biological signal transmission system.

• Journal of Electrochemical Science and Technology
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• 제13권1호
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• pp.71-77
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• 2022

Metal halide perovskites are promising photovoltaic materials, but they still have some issues that need to be solved. Hysteresis is a phenomenon that strongly is correlated with ion migration; thus, a fast, easy, and low-temperature method for measuring ion migration is required. Through selective blocking, ion migration can be measured separately, apart from electron migration. In this study, ion migration in metal halide perovskites was measured using a vertical device. At different temperatures, ionic activation energies were obtained for a range of perovskite compositions such as MAPbI₃, FAPbI₃, CsPbI₃, and MAPbBr₃. By comparing the measured ionic activation energies with the theoretical values, we conclude that among other possibilities, I^- is the migrating ion in MAPbI₃, FAPbI₃, CsPbI₃, and Br- is the migrating in MAPbBr₃.

• 현장농수산연구지
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• 제22권1호
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• pp.55-63
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• 2020

필터 부착에 따른 모형온실 내에서 스펙트럼은 필터에 따른 파장 폭은 넓지만 각 파장대에 따른 피크치는 나타나는 것으로 조사되었다. 각각의 모형온실 내에서 조도 및 광량자속밀도를 측정한 결과 조도는 Blue필터를 부착한 온실이, 광량자 속밀도는 Red필터를 부착한 온실이 가장 높은 것으로 나타났다. 투과율을 조사한 결과 필터를 부착한 온실이 대조구에 대비하여 약 30~40% 낮은 것으로 조사되었다. 적축면상추의 생육기간별 생체중과 건물중을 측정한 결과 대조구온실에서 정식 30일 후에 약 148g으로 가장 높았고, 다음으로 Red필터 부착온실에서 약 143g으로 높았다. 재배기간에 따른 광합성속도는 상추가 성장할수록 낮아지는 경향이었으나, Blue필터 온실은 높아지는 것으로 나타났다. 수분이용효율은 큰 차이는 없었으나 Green영역에서 높은 것으로 조사되었고, 기공전도도는 대조군 온실이 가장 높은 것으로 조사되었다. 안토시아닌 함량은 모든 시험구에서 생육 후기로 갈수록 크게 감소하는 경향이었다.

• Journal of Power Electronics
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• 제7권2호
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• pp.118-123
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• 2007

This paper presents a new ZCS-PWM high frequency inverter. Zero current switching operation is achieved in the whole load range by using a simple auxiliary reverse blocking switch in parallel with series resonant capacitor. Dual duty cycle control scheme is used to provide a wide range of high frequency AC output power regulation that is important in many high frequency inverter applications. It found that a complete soft switching operation can be achieved even for low power setting ranges by introducing high-frequency dual duty cycle control scheme. The proposed high frequency inverter is more suitable for consumer induction heating(IH) applications. The operation and control principle of the proposed high frequency inverter are described and verified through simulated results.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 추계학술대회 논문집
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• pp.305-306
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• 2008

• The Korean Journal of Physiology and Pharmacology
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• 제5권6호
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• pp.511-519
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• 2001

Nimopidine, one of dihydropyridine derivatives, has been widely used to pharmacologically identify L-type Ca currents. In this study, it was tested if nimodipine is a selective blocker for L-type Ca currents in sensory neurons and heterologous system. In mouse dorsal root ganglion neurons (DRG), low concentrations of nimodipine $(<10\;{\mu}M),$ mainly targeting L-type Ca currents, blocked high-voltage-activated calcium channel currents by ${\sim}38%.$ Interestingly, high concentrations of nimodipine $(>10\;{\mu}M)$ further reduced the 'residual' currents in DRG neurons from ${\alpha}_{1E}$ knock-out mice, after blocking L-, N- and P/Q-type Ca currents with $10\;{\mu}M$ nimodipine, $1\;{\mu}M\;{\omega}-conotoxin$ GVIA and 200 nM ${\omega-agatoxin$ IVA, indicating inhibitory effects of nimodipine on R-type Ca currents. Nimodipine $(>10\;{\mu}M)$ also produced the inhibition of both low-voltage-activated calcium channel currents in DRG neurons and ${\alpha}_{1B}\;and\;{\alpha}_{1E}$ subunit based Ca channel currents in heterologous system. These results suggest that higher nimodipine $(>10\;{\mu}M)$ is not necessarily selective for L-type Ca currents. While care should be taken in using nimodipine for pharmacologically defining L-type Ca currents from native macroscopic Ca currents, nimodipine $(>10\;{\mu}M)$ could be a useful pharmacological tool for characterizing R-type Ca currents when combined with toxins blocking other types of Ca channels.

• Journal of electromagnetic engineering and science
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• 제9권1호
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• pp.46-52
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• 2009

This paper conducts a study on the frequency-dependent filtering and blocking effects of a variety of periodic structures, dubbed frequency selective surface(FSS). The periodic structures of interest are 1D and 2D repeated patterns of metal patches or slots sitting on the interface between the two different regions in the layered media which will show the capacitive or inductive behaviors and incorporated with the electromagnetic bandgap(EBG) geometry as another stratified media. Besides the normal substances so called double positive(DPS)-type in the layered media, metamaterials of double negative(DNG) are considered as layering components on the purpose of investigating the unusual electromagnetic phenomena. Frequency responses of transmission(absorption in terms of scattering) and reflection will be calculated by a numerical analysis which can be validated by the comparison with the open literature and demonstrated for the periodic structures embedding metamaterials or not. Most importantly, numerous examples of FSS will present the useful guidelines to have absorption or reflection properties in the frequency domain.

• Journal of Electrochemical Science and Technology
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• 제2권3호
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• pp.143-145
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• 2011

Metal-binding antibiotics are very attractive choices as cation selective ionophores. The ability of tetracycline (TC) antibiotics to bind to metal ions has obtained much attention. TCs exhibit the potentiometric performance changes for various cations dependant on several experiment conditions. In this report, we investigated the potentiometric performance changes of TC as the modification of TC's possible metal binding site. We found that the selectivity alter with the blocking main binding site of ionophores for cations. And, additionally it is possible to control the selectivity of sensors with chemical modification of ionophores.

• ALGAE
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• 제35권4호
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• pp.389-404
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• 2020

Red algal fertilization is unusual and offers a different model to the mechanism of intracellular transport of nuclei and polyspermy blocking. A female carpogonium (egg) undergoes plasmogamy with many spermatia (sperm) simultaneously at the receptive structure, trichogyne, which often contains numerous male nuclei. The pattern of selective transport of a male nucleus to the female nucleus, located in the cell body of the carpogonium, remain largely unknown. We tracked the movement of spermatial nuclei and cell organelles in the trichogyne after plasmogamy using time-lapse videography and fluorescent probes. The fertilization process of Bostrychia moritziana is composed of five distinctive stages: 1) gamete-gamete binding; 2) mitosis in the attached spermatia; 3) formation of a fertilization channel; 4) migration of spermatial nuclei into the trichogyne; and 5) cutting off of the trichogyne cytoplasm from the rest of the cell after karyogamy. Our results showed that actin microfilaments were involved in the above steps of fertilization, microtubules are involved only in spermatial mitosis. Time-lapse videography showed that the first ("primary") nucleus which entered to trichogyne moved quickly to the base of carpogonium and fused with the female nucleus. The transport of the primary male nucleus to the egg nucleus was complete before its second nucleus migrated into the trichogyne. Male nuclei from other spermatia stopped directional movement soon after the first one entered the carpogonial base and oscillated near where they entered trichogyne. The cytoplasm of the trichogyne was cut off at a narrow neck connecting the trichogyne and carpogonial base after gamete nuclear fusion but gamete binding and plasmogamy continued on the trichogyne. Spermatial organelles, including mitochondria, entered the trichogyne together with the nuclei but did not show any directional movement and remained close to where they entered. These results suggest that polyspermy blocking in B. moritziana is achieved by the selective and rapid transport of the first nucleus entered trichogyne and the rupture of the trichogyne after gamete karyogamy.