• Journal of the Korean Applied Science and Technology
• /
• v.21 no.1
• /
• pp.76-88
• /
• 2004

The catalytic oxidation reaction of several cycloolefins in $CH_2Cl_2$ have been investigated using non-redox metalloporphyrin(M = Ga(III), In(III) and TI(III) complexes as a catalyst and sodium hypochlorite as a terminal oxidant. Porphyrins were $(p-CH_3O)$TPP, $(p-CH_3)$TPP, TPP, (p-F)TPP, (p-Cl)TPP and $(F_{20})$TPP (TPP=5,10,15,20-tetraphenyl-21H,23H-porphyrin) and olefins were cyclopentene, cyclohexene, cycloheptene and cyclooctene, The substrate conversion yield(%) was investigated according to the radius effect of non-redox metal ion, substituent effect and hindrance effect of metalloporphyrin. The conversion yield of cycloolefin was in the following order : $C_5$ < $C_6$ < $C_7$ = $C_8$.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.22 no.2
• /
• pp.225-240
• /
• 1997

With the lanuch of the World Trade Organization(WTO) system, National and international trends toward more liberalized regulation of telecommunications terminal equipments drive the globalization of the telecommunications market. Despite of such trends, most countries have long viewed the type approval system as a major hindrance to overseas maketing because of a hodgepodge of diverse type approval system of telecommunications terminal equipments in each country. But, recently, many countries under these situations try to make a better understanding of respective requeirements of each country's many countries under these situations try to make a better understanding of respective requirements of each country'stype approval system, and where possible to strengthen commonalities, through referred to as "multual recognitio" system for the purpose of the development of procedures for hamonization oftype approval system in "one world, one market". Thus, this paper covers the definition, considerations and the case studies of mutual recognition between countries. Also, this paper suggests the desirable and general model of mutual recognition to be applied all the countries, which are being preparing and processing it.g and processing it.

• Journal of Korean Library and Information Science Society
• /
• v.2
• /
• pp.61-77
• /
• 1975

As a reforming work of university education, pilot schools appearing in cach university. In spite of making ;in cffort to csl;lblish the position as university, some of its libraries arc n hindrance to csccllent studies yet. For the most of univcrsity libraries do nct come to the Standard Degree for Establishment of Coll~gc and Univcrsitp. this t h x i s aims to make plans for reaching it after analyzing the current syskms of the cnsc-studies bctwccn "I(" 1.Tnivei-sity and "S" 1Vonic:n's Univcrsity. Hut the obsolcsccnce ratc of books are equal to thc growth rate of them by othcr theses, wc shall maintain two tinlcs the growth rate of coming to thc Standard Dcgrcc for Establishlncnt of College and University. If thcy want to incrcasc library materials, all of them must apply to the niodcl of growth ratc by thc author. ratc by thc author.

• Journal of the Korean Wood Science and Technology
• /
• v.34 no.5
• /
• pp.104-110
• /
• 2006

We investigated why aspen extractives are more resistant in kraft pulping than pine extractives. Residual extractives content in aspen kraft pulps were 0.5~1.1% compared with 0.1~0.2% in pine pulps. This different response arises from the different composition of extractives in wood chips. Resin acids in pine were almost completely removed in kraft pulping but those are not existence in aspen. Slower saponification of aspen steryl esters resulted from different chemical structure of aspen steryl esters. Main sterols in aspen steryl esters were 24-methyl cyclolanostenol which was highly resistant to alkaline hydrolysis with its characteristic steric hindrance. Sterols in aspen were not well removed in kraft pulping. The relative composition of sterol in aspen kraft pulps was increased with increasing pulping time. The presence of fatty acids in aspen kraft pulps is considered to unusual. Fatty acids in alkaline are supposed to be well ionized and removed well in the washing stage. Nevertheless, there were significant amount of fatty acids remaining in aspen kraft pulps.

• Journal of Korean Society of Forest Science
• /
• v.8 no.1
• /
• pp.21-26
• /
• 1968

Chapter 1 in Article 2 of forest law defines the definition of forest. but its meaning is so wide that it itself containg a lot of contradiction in it. And it lose legal adaptation which gives a lot of hindrance with criminal investigation. Furthermore, it has made extension of ferming lands, and promotion of livestocks which are most important matter to be solved in Korea retarded. Such an act made us bewildered to adapt concerned laws being applied to out law. This is to form a basic principal and define its correction. It is required that forestry of Korea should be utilized valuable and reserve forest region instead of definition totally, and the purpose of reforestation should be clear. In addition to above, it is required to define what forestry is, in the direction of reconstructing forestry better in Korea.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.12
• /
• pp.4179-4184
• /
• 2011

The nucleophilic substitution reactions of bis(2,6-dimethylphenyl) chlorophosphate (5), containing the four ortho-methyl substituents, with X-pyridines are investigated kinetically in MeCN at $65.0^{\circ}C$. The free energy correlations for substituent X variations in the nucleophiles exhibit biphasic concave upwards with a breakpoint at a X = 3-Cl. Unusual positive ${\rho}_X$ (= +5.40) and negative ${\beta}_X$ (= -0.83) values are obtained with the weakly basic pyridines. The pyridinolysis rate of 5 is hundreds times slower compared to that of bis(phenyl) chlorophosphate because of the steric hindrance of the four ortho-methyl substituents in the two phenyl rings. Ion-pair mechanism is proposed and positive ${\rho}_X$ and negative ${\beta}_X$ values are substantiated by an imbalance of the transition state.

• Journal of Fisheries and Marine Sciences Education
• /
• v.18 no.1
• /
• pp.1-10
• /
• 2006

A total of 480 questionnaires were sent out for this study and 414 collected, and 410 analyzed excluding inadequate ones. The major findings were as follows:First, the middle school teachers recognized their schooling culture to be neither positive nor negative in nature, rather neutral. They felt administrative work was over emphasized in schools. Second, their overall job satisfaction was slightly above neutral. Factors of organizational structure, human relations, and work-itself showed above neutral and only 'reward and self-actualization' factor below neutral: The 'reward and self-actualization' factor was hindrance to job satisfaction.Third, schooling culture and job satisfaction showed negative correlation: a toxic culture.

• School Mathematics
• /
• v.4 no.1
• /
• pp.49-62
• /
• 2002

developed by solving practical problems and gradually formalized and abstracted. But school mathematics seemed to stress the formalized and abstracted mathematics. The same is the case with calculus. In particular, it appeared extremely in teaching of calculus. It caused hindrance of learning and indeed, many students had difficulties in teaming of calculus. Therefore this study investigates the various approaches of calculus teaching and the history of calculus which include approaches by Archimedes, Galileo, Newton, Leibniz and Weierstrass etc. This may offer the implication for calculus teaching and we can find the alternative on the method of calculus teaching in historico-genetic principle. Finally we suggest the direction of calculus teaching from this perspective in tile concrete.

• Journal of Photoscience
• /
• v.8 no.2
• /
• pp.79-82
• /
• 2001

2-(p-Diethylaminostyryl)pyrrole (I) and 2-[5-diethylaminothienyl]vinyl]pyrrole (II) derivatives with systematic variation of the acceptors have been synthesized and their first hyperpolarizabilities were measured. The $\beta$ values increased systematically as the aromatic resonance energy decreased. Moreover, the value of $\beta$ for the former increased gradually as the acceptor strength increased. The opposite trend observed in the latter series of compounds has been attributed to the distorted structure caused by the steric hindrance between the N-methyl group and the acceptor moiety.

• The Journal of the Korea Contents Association
• /
• v.2 no.4
• /
• pp.76-84
• /
• 2002

The conventional database evaluation method is carried out by the way in which the person in charge of each specialty database(DB manager) composes the evaluation sheets for corretionㆍrevision on the already-constructed database in a manual method and carries out the measurement and re-education of DB workers based upon it. As a result, that way consumes much time on career information and measurement works about DB workers, causing low time and cost efficiency and lack of systematic management of DB workers, resulting in becoming the hindrance factor of databases quality improvement. This research provides on-line, red-time results of measurements about the efficiency of DB production and DB workers by combining the static measurement with dynamic measurement by DB manager, both of which utilize the System. Therefore, the DB manager can contribute to the improvement of DB quality by determining the continuation of DB production by DB workers or carrying out the re-education of DB workers without being affected by time or spacial constraints.