• Journal of the Korean Chemical Society
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• v.35 no.1
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• pp.24-37
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• 1991

We synthesized the binuclear Tetradentate Schiff base nickel(II) and copper(II) complexes ; [Ni(II)$_2$(SMPO)$_2$(L)$_2$], [Ni(II)$_2$(SPPD)$_2$(L)$_2$] and [Cu(II)$_2$(SMPD)$_2$] and [Cu(II)$_2$(SPPD)$_2$] (where, L : Py, DMSO and DMF). We identified the structure of these complexes by elemental analysis, IR-spectrum, T.G.A, D.S.C and ESR measurements. According to the results of cyclic voltammetry and DPP measurements in aprotic solvent included 0.1M TEAP as supporting electrolyte, we knew that diffusional controlled redox process of one step with one electron was irreversible process in 0.1M TEAP-Py solution. Also it was reversible or quasi reversible process in 0.1M TEAP-DMSO solution and reversible or E.C reaction mechanism in 0.1M TEAP-DMF solution at mononuclear complexes ; [Cu(II)(SOPD)] and [Ni(II)(SOPD)(L)$_2$]. But, we knew that diffusional controlled redox process of two step for one electron of binuclear complexes was as follows. The values of redox potential for dimeric complexes in 0.1M TEAP-L solution (where, L ; Py, DMSO and DMF) with scan rate 100mV/sec.

• Journal of the Korean Chemical Society
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• v.31 no.3
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• pp.250-257
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• 1987

The electrical conductances for the thorium (IV) complexes with crown ethers have been measured in DMSO, and water solvents, and the oxidation-reduction reaction mechanisms, electron number and diffusion coefficients in the reversible reduction process have been examined by polarography and cyclic voltammography. The dissociation mole ratio of $Th^{4+}$ and nitrate ion are 1:1 and in aprotic solvent, and 1:4 in protic solvent like as water. The limiting molar conductances of all complexes in aprotic solvent have been found to be in the range of $92.2{\times}159$ $ohm^{-1}cm^2mol^{-1}$. In aprotic solvent, DMSO, the reduction of each complex is reversible by one electron reduction of one step, and the range of diffusion coefficients is obserbed to be $5.83\;10^{-6}{\sim}6.90{\times}10^{-6}$. The complexes which have reduction step were hydrolyzed above at 1.8volt with reference saturated calomel electrode, generating the hydrogen gas. The reaction mechanisms of thorium (IV)-crown ether complexes appear as follows. ${Th_m(IV)L_n(H_2O)_x(NO_3)_{4y}}_=^{DMSO} {\overline{{Th_m(IV)L_n(H_2O)_x(NO_3)_{4y-1}}}^+ + NO_3-$

• Nuclear Engineering and Technology
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• v.9 no.2
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• pp.75-81
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• 1977

This experiment has been carried out to determine the pH dependent cation exchange capacity concerning the sorption phenomenon of long-lived radionuclides contained in low-level liquid radioactive waste on various clay minerals. The pH dependent cation exchange capacity determined by Sawhney's method are used to the analysis of sorption phenomenon. About 70 percent of the total cation exchange capacity is contributed by the pH dependent CEC due to the negative charge originated naturally in clays in case of clinoptilolite, vermiculite and sodalite. It is sugested in this test that the high neutral salt CEC, that is, highly charged clays would show good fixation yield. The removal of radionuclides at the pH range more than pH 9 is considered the hydroxide precipitation of metal ion rather than the cation exchange. The Na-clay prepared by the method of successive isomorphic substitution with electrolyte showed a considerable improvement in removal efficiency for the decontamination.

• Journal of Conservation Science
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• v.31 no.4
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• pp.351-360
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• 2015

This is the result of the study on the temporary fortifier using sublimation type Consolidate is Cyclododecane to prepare plan for reinforcement of the surface part that can be damaged during the dismantling of stone cultural heritages. To supplement the disadvantages of the existing reinforcement methods using intumescent urethane foam, Cyclododecane was diluted in solvent to reinforce the surface and inside desquamation, and after dismantling the framework, it sublimated by imposing heat of about $60^{\circ}C$. Such method can guarantee the strength needed for reinforcement of the damaged surface with outstanding reversibility of Cyclododecane being entirely sublimated. But, it shows big difference of effect according to the solvent, so it shall be diluted in petroleum ether or heated in a double boiler. Therefore, considering the working conditions at the site, it seems the most appropriate to use petroleum ether double boiler heating method for injection and filling of the desquamation part and temporary reinforcement processing with Cyclododecane diluted in petroleum ether for surface spraying.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.3
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• pp.359-370
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• 2013

Lin and Chan proposed a reversible secret image sharing scheme in 2010. The advantages of their scheme are as follows: the low distortion ratio, high embedding capacity of shadow images and usage of the reversible. However, their scheme has some problems. First, the number of participants is limited because of modulus prime number m. Second, the overflow can be occurred by additional operations (quantized value and the result value of polynomial) in the secret sharing procedure. Finally, if the coefficient of (t-1)th degree polynomial become zero, (t-1) participants can access secret data. In this paper, an improved reversible secret image sharing scheme which solves the problems of Lin and Chan's scheme while provides the low distortion ratio and high embedding capacity is proposed. The proposed scheme solves the problems that are a limit of a total number of participants, and occurrence of overflow by new polynomial operation over GF($2^8$). Also, it solve problem that the coefficient of (t-1)th degree polynomial become zero by fixed MSB 4-bit constant. In the experimental results, PSNR of their scheme is decreased with the increase of embedding capacity. However, even if the embedding capacity increase, PSNR value of about 45dB or more is maintained uniformly in the proposed scheme.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.12
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• pp.67-75
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• 2016

DNA computing technology makes the interests on DNA storage and DNA watermarking / steganography that use the DNA information as a newly medium. DNA watermarking that embeds the external watermark into DNA information without the biological mutation needs the reversibility for the perfect recovery of host DNA, the continuous embedding and detecting processing, and the mutation analysis by the watermark. In this paper, we propose a reversible DNA watermarking based on circular histogram shifting of DNA code values with the prevention of false start codon, the preservation of DNA sequence length, and the high watermark capacity, and the blind detection. Our method has the following features. The first is to encode nucleotide bases of 4-character variable to integer code values by code order. It makes the signal processing of DNA sequence easy. The second is to embed the multiple bits of watermark into -order coded value by using circular histogram shifting. The third is to check the possibility of false start codon in the inter or intra code values. Experimental results verified the our method has higher watermark capacity 0.11~0.50 bpn than conventional methods and also the false start codon has not happened in our method.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.2
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• pp.17-26
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• 1979

Comparative tolerance of the new rice varieties from Indicax Japonica cross to elastic and plastic chilling injuries was examined at the 3rd leaf-stage, the most sensitive stage to chilling during nursery, using a chilling chamber set 11\circ C, 13hrs. 20K lux day/5$^{\circ}C$ night. Seedlings were reared until 35 days after seeding in a 26\circ C, 13hrs. day / 18\circ C night chamber except the period of chilling treatment for 0, 3, 4, 6, 8 or 10 days. The new varieties were approximately twice susceptible to elastic injuries, and thrice susceptible to plastic injuries than the Japonica varieties in the term of chilling duration. Among the variables indicating apparant chilling injuries the reduction in dry matter responded most sensitively and differentiated well the varietal difference in chilling resistance even with shorter chilling period. Sequential aspects of the cause and effect relations involved in the development of the apparant chilling injuries are discussed and a schematic diagram is presented as Fig. 5 in the text.

• Journal of the Korean Chemical Society
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• v.51 no.1
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• pp.65-72
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• 2007

The purpose of this study was to examine the 7th national science curriculum (chemistry domain) regarding the meanings of ‘mulgil' (Korean), the particulate nature of matter, and the state of matter. It was found that the term of ‘mulgil' was being used vaguely as representing material, matter, or substance without clear definition. This was problematic by reason that it could hinder students from having the concept of substance. Regarding the particulate nature of matter, molecule was introduced as a basic unit of matter at grade 7, prior to atom and ion, which were introduced at grade 9 and 10, respectively. It is necessary to reconsider the sequence of each particle concept to provide students with more consistent and comprehensive understanding of structure of matter. In the case of change of state, key concepts such as conservation of matter or reversibility were omitted in the curriculum document, and explanations based on various aspects of particles were somewhat insufficient. The concept of matter is fundamental to chemistry, and we must recognize it as a concept that needs to be taught clearly. Implications for curriculum revision were discussed.

• Proceedings of the Membrane Society of Korea Conference
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• 1996.04a
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• pp.46-47
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• 1996

막분리 공정의 공업적인 이용을 위해서는 막을 특정 용기에 적재한 모듈의 형태가 요구되는데 모듈의 형태에 따라 평판형(plate and frame), 나권형(spiral wound), 관형(tubular), 중공사형(hollow fiber)모듈 등이 있다. 이 중에서 관형 시스템은 내경이 12.5~25 mm, 길이 0.6~6.4 m에 이르는 비교적 큰 open channel로 되어 있으며 공급액 유로가 일반적으로 커서 전처리를 행하지 않고도 fouling이 적으며, 또한 막 표면의 세정이 약품에 의한 것 이외에 스폰지 볼 등에 의한 물리적 세정도 가능하므로 응용 범위가 넓다는 것이 특징이다. 한외여과 공정의 가장 큰 문제점은 농도분극 및 fouling 현상에 의한 플럭스 감소이다. 농도분극 현상은 경계층에서 용질의 대류,확산적인 전달에 기인하여 막 표면으로 갈수록 진해지는 용액층의 형성을 의미한다. 이 현상은 가역적인 과정으로서 감압함으로 원상태로 회복이 가능하며 조작 압력에서 정상상태가 되면 막투과 플럭스는 일정한 값을 유지한다.

• Journal of Hospice and Palliative Care
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• v.11 no.4
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• pp.175-180
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• 2008

진행된 암환자에서 피로는 70% 이상이 경험하게 되는 흔한 증상이며 삶의 질을 저하시키는 주된 요인이다. 피로에 대한 선별검사는 "피곤하거나 지친감이 있나요?"라는 단순한 질문으로 가능하며 이미 개발된 평가도구를 사용하여 평가할 수 있다. 동반 질환이나 피로의 원인을 알기 위한 병력청취와 검사실 검사가 필요할 수 있으며 결과에 따라 가역적 인자를 치료하는 과정이 우선되어야 한다. 적절한 약물치료를 시행하여 증상을 호전시킬 수 있으며 이중 methylphenidate는 암 연관 피로를 호전시키고 마약성 진통제에 의한 진정에 효과가 입증되었다. 환자의 여명에 따라 부신 피질 호르몬제도 사용할 수 있고, 운동 및 환자의 교육과 영양관리 또한 중요하다.