• Journal of the Korean Wood Science and Technology
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• 제36권2호
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• pp.56-62
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• 2008

The surface and edge structure of OSB is defined by surface strand orientation and strand mat thickness variation parallel to the length of the panel using video-microscope. The bending strength of OSB was correlated with surface strand orientation and decreased with increasing the orientation angle in the direction parallel to length of the panel. Average strand mat thickness variation parallel to the length of the panel did not influence the bending strength, but the bonding characteristics among the outermost strands affects the bending strength of OSB. Hankinson formula can be used to predicts the MOE according to strand orientation in the surface of OSB, and more precise strand alignment and reducing thickness variation should be important in the structural performance of OSB panels.

• BMB Reports
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• 제38권6호
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• pp.690-694
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• 2005

Transcription termination of the human mitochondrial genome requires specific binding to termination factor mTERF. In this study, mTERF was produced in E. coli and purified by two-step chromatography. mTERF-binding DNA sequences were isolated from a pool of randomized sequences by the repeated selection of bound sequences by gel-mobility shift assay and polymerase chain reaction. Sequencing and comparison of the 23 isolated clones revealed a 16-bp consensus sequence of 5'-GTG$\b{TGGC}$AGANCCNGG-3' in the light-strand (underlined residues were absolutely conserved), which nicely matched the genomic 13-bp terminator sequence 5'-$\b{TGGC}$AGAGCCCGG-3'. Moreover, mTERF binding assays of heteroduplex and single-stranded DNAs showed mTERF recognized the light strand in preference to the heavy strand. The preferential binding of mTERF with the light-strand may explain its distinct orientation-dependent termination activity.

• BMB Reports
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• 제38권2호
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• pp.161-166
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• 2005

Functional protein of MB78 bacteriophage having apparent molecular weight of 22 kDa is expressed from 1.7 kb HindIII G fragment. The nucleotide sequence of this fragment showed two open reading frames of 222 and 196 codons in tail-to-tail orientation separated by a 62-nucleotide intercistronic region. The ORF of 22 kDa protein is present in opposite orientation, i.e. in the complementary strand, preceded by a strong ribosomal binding site and a promoter sequence. Another ORF started from the beginning of the fragment whose promoter region and translational start site lies in the 0.45 kb HincII U fragment which is located next to the HindIII G fragment, that has the sequence for DNA bending. 3' end of the fragment has high sequence homology to the EaA and EaI proteins of bacteriophage P22, a close relative of MB78 phage.

• International Journal of Reliability and Applications
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• 제8권1호
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• pp.111-124
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• 2007

In this paper, we apply insightful statistical reliability tools to manage and seek improvements in the strengths of Oriented Strand Board (OSB). As a part of the OSB manufacturing process, the product undergoes destructive testing at various intervals to determine compliance with customers' specifications. Workers perform these tests on sampled cross sections of the OSB panel to measure the tensile strength, also called internal bond (IB), in pounds per square inches until failure. Additional stiffness strength tests include parallel and perpendicular elasticity indices (EI), which are taken from cross sectional samples of the OSB panel in the parallel and perpendicular directions with respect to the orientation of the wood strands. We explore both graphically and statistically these "pressure-to-failures" of OSB. Also, we briefly comment on reducing sources of variability in the IB and EI of OSB.

• Korea-Australia Rheology Journal
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• 제11권4호
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• pp.293-304
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• 1999

Refinements of classical theories for entangled or crosslinked polymeric systems have led to incommensurable models for rubber networks and polymer melts, contrary to experimental evidence, which suggests a great deal of similarity. Uniaxial elongation and compression data of linear and branched polymer melts as well as of crosslinked rubbers were analyzed with respect to their nonlinear strain measure. This was found to be the result of two contributions: (1) affine orientation of network strands, and (2) isotropic strand extension. Network strand extension is caused by an increasing restriction of lateral movement of polymer chains due to deformation, and is modelled by a molecular stress function which in the tube concept of Doi and Edwards is the inverse of the relative tube diameter. Up to moderate strains, $f^2$ is found to be linear in the average stretch for melts as well as for rubbers, which corresponds to a constant tube volume. At large strains, rubbers show maximum extensibility, while melts show maximum molecular tension. This maximum value of the molecular stress function governs the ultimate magnitude of the strain-hardening effect of linear and long-chain branched polymer melts in extensional flows.

• 대한수학교육학회지:학교수학
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• 제9권2호
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• pp.197-222
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• 2007

본 연구는 최근 기하 교육 동향과 전미수학교사협의회에서 2000년대의 수학교육의 방향과 관련해서 제시한 기하 교육의 규준에 비추어 현실적 수학교육에 기초한 네덜란드의 초등학교 기하 교육과정에 대해 알아보고, 우리나라의 초등학교 도형 영역 지도를 위한 시사점을 제시하는 데 그 목적이 있다. 이런 목적을 달성하기 위해 네덜란드의 초등학교 기하 교육의 역사를 살펴보고, 네덜란드의 초등학교 기하 교육과정에 중요한 영향을 미치는 요소인 일반 목표와 기하 영역의 핵심 목표, RME에 기초한 네덜란드의 초등학교 수학 교과서의 지도 내용과 지도 방법의 특징을 살펴보았다. 그 결과 우리나라 도형 영역의 교육과정과 교과서 개발을 위해 논의할 문제로 지도 내용의 측면에서 공간 방향의 도입, 공간 시각화와 공간 추론의 강화, 지도방법의 측면에서 공간적 접근과 도형적 접근의 균형, 직관적 접근의 중시, 통합적 접근의 고려 등을 제안하였다.

• Journal of Microbiology and Biotechnology
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• 제27권6호
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• pp.1198-1203
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• 2017

Hrr25, a casein kinase $1{\delta}/{\varepsilon}$ homolog in budding yeast, is essential to set up mono-orientation of sister kinetochores during meiosis. Hrr25 kinase activity coordinates sister chromatid cohesion via cohesin phosphorylation. Here, we investigated the prophase role of Hrr25 using the auxin-inducible degron system and by ectopic expression of Hrr25 during yeast meiosis. Hrr25 mediates nuclear division in meiosis I but does not affect DNA replication. We also found that initiation of meiotic double-strand breaks as well as joint molecule formation were normal in HRR25-deficient cells. Thus, Hrr25 is essential for termination of meiotic division but not homologous recombination.

• 대한관절경학회지
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• 제9권2호
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• pp.222-231
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• 2005

목적: 저자들은 5가닥의 자가 슬괵건을 이용하여 기존의 전내측 다발에 부가적인 후외측 다발을 통한 전방 십자인대 이중 다발 재건술을 소개하고자 한다. 수술 술기: 경골 터널은 기존의 단일 터널 방법을 사용하였고, 대퇴 터널은 전내측과 후외측 다발을 위한 이중 터널 방법을 사용하였다. 전내측 대퇴 터널은 최소한의 대퇴 과간 절흔 성형술 후 기존의 방법과 동일하게 11시 혹은 1시 방향에 대퇴과 절흔의 후방 경계(over-the-top)에서 후방 피질골이 1 mm 두께로 남아 있게 만든다. 또한 후 외측 대퇴 터널은 outside-in 방법을 사용하여 관절 내 터널 위치는 슬관절 90도 굴곡 상태에서 외측 반월상 연골 후각의 경골 부착부 내연(inner margin)에서 외측 대퇴과 내측벽의 상방 $5{\sim}7mm$ 부위에 4.5 mm reamer 이용하여 만들어 준다. 이중 다발을 위한 이식건으로 전내측 다발은 기존의 4가닥 슬괵건을 사용하고 후외측 다발은 반건양건 단일 가닥으로 만든다. 대퇴 터널 고정 방법으로 전내측 다발은 rigid fix system으로 고정하며 후외측 다발은 관절 밖에 miniplate를 이용하여 endobutton 방식으로 결찰로 고정한다. 이 후 경골 터널 고정은 슬관절을 $10{\sim}20$도 굴곡 상태에서 이중 다발을 함께 인장 강도를 주고 간섭 나사못으로 고정하고 post tie로 보강한다. 결론: 저자들은 비교적 우수한 결과를 보여주었던 기존의 전내측 다발에 회전 안정성을 위한 부가적인 후외측 다발을 통해 5가닥(경우에 따라 6가닥)의 자가 슬괵건을 이용한 이중 다발 재건술을 시행함으로써 좋은 결과가 기대된다.

• 수산해양기술연구
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• 제26권2호
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• pp.204-212
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• 1990

The SMC composite, now being considered in certain structural applications, is anticipated to experience repeated loading during service. Thus, understanding of the fatigue behavior is essential in proper use of the composite material. In this paper, using the SMC composite composed of E-glass chopped strand and unsaturated polyester resin three point bending fatigue tests are carried out to investigate the fatigue crack propagating behavior under various cyclic stresses and fatigue damage of various microcrack forms. The following results are obtained from this study; 1) Most of the total fatigue life of the SMC composite is consumed at the initial extension or the growth of the macroscopic crack. 2) A Paris' type power-law relationship between the crack propagation rate and stress intensity factor range is obtained, and the value of material constant m is much higher (m=9~11)than that of other metals. 3) In case of high cyclic stress the fatigue damage show high microcrack density and short crack length, but in case of low cyclic stress does it vice versa. 4) Fatigue damage is characterized by microcrack density, crack length and distribution of crack orientation.

• Journal of Ginseng Research
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• 제7권2호
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• pp.172-192
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• 1983

Light environment and growth of Panax ginseng In habitat and cultivation under natural shade were renewed. Grower's experiences on ginseng stand In relation to light environment were assessed. Change of shading method and grower's concepts on light requirement of ginseng plant in Korea, Manchuria and Japan was counted. Growth of wild ginseng was better under rich light. Optimum crown density index appeared to be 0.7 In natural habitat and 0.4 to 0.7 for the cultivation in forest. Change of light Intensity in forest was greatest in May and reached near to constant value (from 40% to 3% for broad leaf deciduous forest and loom 4% to 2% for pine forest). Insufficient light condition induced long and thin stem, poor flowering and seed bearing, and sequent dormancy. Relation between light and ginseng strand was not clear but light Interception with cool weather was effective. Topography and orientation of bed have been deeply considered for light environment. Panel or bark of won were used for shading in deep forest manly In Manchuria while reed blind and straw thatch were used in Korea. Kinds and number of shades material and seasonal or daily schedule have been simplified probably by labor pressure due to eulargement of plantation. Post height has been greater while width of roof, bed and ditch has changed lisle. Scientific survey in the past omitted important light control methods (complete light hardening etc) which has been practiced in specific areas. The concept and technique of light control in the past in Korea were delicate and intensive including the control of temperature and moisture. For the application of old concept in modem cultivation precise Investigation of the technique including the measurement of light, temperature and moisture is needed.