• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.77-82
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• 2011

A new high performance liquid chromatograpgy (HPLC) stationary phase that possesses an internal carbonyl functional group is synthesized by heterogeneous "graft from" method. This new stationary phase, poly (vinyl octadecanoate) grafted silica (Sil-2) is then characterized by different physico-chemical methods such as diffuse reflectance infrared fourier transform, suspension state $^1H$ NMR, solid state $^{13}C$ CP/MAS NMR, $^{29}Si$ CP/MAS NMR, elemental analysis and thermogravimetric analysis. Chromatographic properties of Sil-2 were evaluated under reversed phase condition by separating polycyclic aromatic hydrocarbons (PAHs) and comparing the chromatographic results with those on polymeric as well as monomeric octadecylated silica stationary phases.

• Journal of Ecology and Environment
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• v.29 no.5
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• pp.425-432
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• 2006

The tadpoles of 12 Korean anuran species, including Bombina orientalis, Bufo gargarizans, B. stejnegeri, Hyla japonica, Kaloula borealis, Rana dybowskii, R. huanrenensis, R. coreana, R. nigromaculata, R. chosenica, R. rugosa, and R. catesbeiana, were classified based on their morphological characteristics. We collected eggs or tadpoles of the 12 Korean anuran species from Gangwon, Incheon, Chungcheong, and Gyeonggi districts in 2005 and 2006 breeding seasons. When the tadpoles reached at $27{\sim}37$ Gosner's developmental stages, we described morphological characteristics of the tadpoles of each anuran species and measured their physical parameters such as total length, body length, and body mass. After that, we chose 12 morphological characteristics to identify each species and to use them as classification keys such as eye location, caudal musculature pattern, spiracle location, oral disc morphology, and labial tooth row formula. In this paper, we presented classification keys, morphological characteristics, and drawings for the tadpoles of 12 anuran species.

• Journal of the Korean Data and Information Science Society
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• v.19 no.4
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• pp.1449-1463
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• 2008

This paper considers three different models with two functional forms, Cobb-Douglas and Translog, for the stochastic frontier production function of food manufacturing industry of Bangladesh over the period 1981-1982 to 1999-2000. The models are proposed by Battese and Coelli (1992, 1995) and Huang and Liu (1994). The technical efficiency, total factor productivity, technological change and technical efficiency change have been estimated in the frontier models. The results indicate that 41.47%, 59.30% and 70.98% of the potential output are being realized in this sector. The mean increments in total factor productivity are approximately 2%, 9% and 4% respectively.

• The Korean Journal of Zoology
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• v.36 no.4
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• pp.580-587
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• 1993

북방산개구리의 성체 수컷들 년중 채집하여 gonadosomatic index(GSI)와 정자형성과 정 및 정소내 testosterone양의 변화를 조사하였다 정자형성은 8월에 시작되어 9월에 가장 활발하게 진행되었으며 이때 GSI도 가장 높았고 세정관의 단면적도 가장 넓었다 번식기(2월) 이후 일정기간 동안에는(3월-7월) 정자형성이 정지되었으며, GSI나 세정관의 단면적도 최저치를 나타내었다. 정소내 testosterone양은 11월부터 급격히 증가하여 2월에 가장 높았으며 3월부터 급격히 감소되어 10월 까지 매우 낮은 농도를 유지하였다. Interstitial cell의 수도 동면기간이 찰동기 보다 훨씬 많았으며 핵의 크기도 동면기간이 훨씬 컷다. 따라서 testosterone의 생성 증가와 interstitial cell의 활성화가 일치함을 알 수 있었다. 본 결과들은 북방산개구리의 정 소에서는 정자형성과정이 불연속적으로 일어난다는 것과 2월 이후에는 testosterone의 양이 급격히 줄어드는 것으로 보아 이 개구리의 번식기가 2월임을 확인해 주고 있다.

• The Korean Journal of Zoology
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• v.37 no.1
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• pp.58-65
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• 1994

Phosphatase의 저해제로 알려진 okadaic acid(OA)가 한국산 개구리(북방산개구리 참개구리) 난자의 성숙에 미치는 효과를 조사하였다. 북방산개구리 난자에 약 50 nl의 okadaic acid(0 5-500 mM)를 미세주입한 후 18시간 배양한 결과 0.5 mM의 농도에서 부터 난자의 핵붕괴를 일으키기 시작하였다 동면초기에 처리한 progesterone에 반응하지 않는 난자들도 OA에 의하여 성숙을 일으켰으며. 이 성숙은 배양액에 첨가한 cycloheximide(10 mg/ml)에 영향을 받지 않았다 또한 OA의 처리를 받고 일정시간 배양한 난자의 세포질에는 미성숙 난자의 성숙을 유도하는 maturation promoting factor (MPF)의 활성이 생기었다 참개구리의 난자도 역시 OA에 의해 성숙이 유도되었으며, 주입 후 6시간에서부터 핵붕괴가 일어나기 시작하였다 참개구리에서도 OA의 처리가 MPF의 활성을 촉진하는 것을 세포질내에 Hl histone kinase의 활성도가 증가하는 것으로 확인할 수 있었다 참개구리에서도 OA에 의한 성숙은 cycloheximide나 CAMP에 의해 영향을 받지 않았다 이러한 결과들은 개구리 난자의 MPF 활성화와 성숙과정에 phosphatase가 관여함을 보여주는 것이다.

• Korean Journal of Environment and Ecology
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• v.11 no.4
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• pp.391-396
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• 1998

Herpetofauna of the Naesorak in Sorasan National Park was carried out both June 30, 1997~July 3, 1997. 6 species of 5 Families in Amphibian and 3 species of 3 families in Reptilian were observed in thes survey. It was observed relatively poor biota to Kaya, Sokri, and Chri National Park in Korea. There were three Specific Endangered Animal assigned by Minister of Environment such as Bufo stejnegeri, Rana dybowskii and Eremius argus. Especially Eremius argus was abundantly distributed around Limansuryonjang. So Limkansuryonjang should be conserve for Eremias argus's stable environmental condition.

• Carbon letters
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• v.18
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• pp.43-48
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• 2016

Sulphonated polysulphone (SPS) has been synthesized and subsequently applied as binder for graphene oxide (GO)-based electrodes for development of electrochemical supercapacitors. Electrochemical performance of the electrode was investigated using cyclic voltammetry in 1M Na₂SO₄ and 1M KOH solution. The fabricated supercapacitors gave a specific capacitance of 161.6 and 216.8 F/g with 215.4 W/kg and 450 W/kg of power density, in 1M Na₂SO₄ and 1M KOH solutions, respectively. This suggests that KOH is a better electrolyte than Na₂SO₄ for studying the electrochemical behavior of electroactive material, and also suggests SPS is a good binder for fabrication of a GO based electrode.

• Journal of Power Electronics
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• v.15 no.4
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• pp.886-898
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• 2015

The design feasibility of a micro unidirectional DC transmission system based on an input-parallel output-parallel (IPOP) converter is analyzed in this paper. The system consists of two subsystems: an input-parallel output-series (IPOS) subsystem to step up the DC link voltage, and an input-series output-parallel (ISOP) subsystem to step down the output voltage. The two systems are connected through a transmission line. The challenge of the delay caused by the communication in the control system is addressed by introducing a ring communication structure, and its influence on the control system is analyzed to ensure the feasibility and required performance of the converter system under practical circumstances. Simulation and experiment results are presented to verify the effectiveness of the proposed design.

• Earthquakes and Structures
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• v.4 no.6
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• pp.685-710
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• 2013

Static torsional provisions employing equivalent lateral force method (ELF) require that the earthquake-induced lateral force at each story be applied at a distance equal to design eccentricity ($e_d$) from a reference resistance centre of the corresponding story. Such code torsional provisions, albeit not explicitly stated, are generally believed to be applicable to the regularly asymmetric buildings. Examined herein is the applicability of such code-torsional provisions to buildings with set-back using rigid as well as flexible diaphragm model. Response of a number of set-back systems computed through ELF with static torsional provisions is compared to that by response spectrum based procedure. Influence of infill wall with a range of opening is also investigated. Results of comprehensive parametric studies suggest that the ELF may, with rational engineering judgment, be used for practical purposes taking some care of the surroundings of the setback for stiff systems in particular.

• Journal of Sensor Science and Technology
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• v.30 no.5
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• pp.286-289
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• 2021

Image classification is one of the fundamental applications of computer vision. It enables a system to identify an object in an image. Recently, image classification applications have broadened their scope from computer applications to edge devices. The convolutional neural network (CNN) is the main class of deep learning neural networks that are widely used in computer tasks, and it delivers high accuracy. However, CNN algorithms use a large number of parameters and incur high computational costs, which hinder their implementation in edge hardware devices. To address this issue, this paper proposes a lightweight image classifier that provides good accuracy while using fewer parameters. The proposed image classifier diverts the input into three paths and utilizes different scales of receptive fields to extract more feature maps while using fewer parameters at the time of training. This results in the development of a model of small size. This model is tested on the CIFAR-10 dataset and achieves an accuracy of 90% using .26M parameters. This is better than the state-of-the-art models, and it can be implemented on edge devices.