• Conservation Science in Museum
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• v.2
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• pp.27-34
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• 2000

24 wooden objects excavated from Daho-ri were identified into 8 categories such as Quercus spp. (37.7%), Castanea crenata (8.3%), Prunus (8.3%), Ilex (4.1%), Alnus spp. (25%), Prunus spp. (4.1%), Zelkova serrata (4.1%) and Fraxinuse (8.3%). Physical properties of the above high water content, high contraction rate and significant density reduction. As for degradation pattern, observation with polarizing microscope showed significant decrease of double reflection phenomenon in most of the excavated objects excluding vessel compared to other kinds of objects, and observation with SEM showed remarkable degradation of organization structure including the 2nd cell wall of wood. Reagent can be easily penetrated and diffused into the objects with high degradation rate, so it's beneficial to treat them with polymers such as PEG#4000(MW:3,350), but in order to prevent contraction and change in shape, high concentration of Reagent is required in treatment to hold wood organization structure.

• Journal of Korean Home Economics Education Association
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• v.17 no.1 s.35
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• pp.69-84
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• 2005

The purpose of this study was to develop and evaluate the effectiveness of an educational program, based on the family life education theory and the needs of the adolescents, for the improvement of the relationship between adolescents and their parents. Aimed to be applicable in the actual school environment, the program was practiced and successfully proved its effectiveness. Named 'Parents and I : Is It Good This Way? Over the Generation Gap', the program is composed of themes such as 'Understanding the importance of the parent-child relationship', 'Understanding parents', and 'Having friendly communication with parents', and was practiced five times, once every week, at H girls' high school located in Seoul. An evaluation was done on adolescents to see the effectiveness of the parent-child relationship improvement program: there was a meaningful distinction between the results of the pre-test and the post-test. The participants responded that they could have a chance to understand their mid-aged parents and to express their feelings and thoughts, and evaluated that the anger-control program was a training for them to express their emotions in a rational way.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.11
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• pp.966-977
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• 2015

This paper presents a novel modified coaxial cavity resonator and its application to bandpass filters with compact size and improved quality factor(Q-factor). The proposed resonator is made up of ${\Gamma}-shape$ or curved four inner conductive posts within a single cavity, which provides quadruplet to realize bandpass filter. No metallic walls inside the cavity are required, and thus the utilization efficiency of the cavity space is improved. As a result, the unloaded Q can be approximately 15 % higher in comparison to the conventional coaxial resonator, or more than 35 % volume saving can be achieved while maintaining the similar Q-factor value with the conventional designs. In addition, due to the multiple cross-coupling occurring within the cavity, including the source-to-load coupling, four flexible transmission zeros can be created to realize different filtering functions. Simulations as well as experimental results of four- and eight-pole filters are presented to validate this attractive design concept. Good agreement between measured and computed results is obtained.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.8
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• pp.829-837
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• 2012

Direct numerical simulations were carried out for turbulent channel flows with $Re_{\tau}$ = 180, 395 and 590 to investigate the turbulent flow structure related to the Reynolds shear stress. By examining the probability density function, the second quadrant (Q2) events with the largest contribution to the mean Reynolds shear stress were identified. The change in the inclination angle of Q2 events varies with wall units in $y^+<50$ and with the channel half height in y/h > 0.5. Conditionally averaged flow fields for the Q2 event show that the flow structures associated with Reynolds shear stress are a quasi-streamwise vortex in the buffer layer and a hairpin-shaped vortex in the outer layer. Three-dimensional visualization of the distribution of high Reynolds shear stress reveals that the organization of hairpin vortices in the outer layer having a size of 1.5~3 h is associated with large-scale motions with high Reynolds shear stress in the outer layer.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.9
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• pp.1264-1270
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• 2018

Blockchain is a technology that directly connects each node to P2P method, except for the central server. A public blockchain is one of the blockchain types, anyone can participate without any restriction. If some node find nonce, which node can broadcasted data to all nodes. At this time, if a node that finds a nonce hides malicious code in the block, all nodes participating in the chain may be infected with malicious code due to the characteristics of the decentralization system of the blockchain. In this paper, to solve the problem that hackers can participate as an any node, we propose that a user with malicious intent can not participate as a node through a firewall with AI technology. This will improve the reliability of the propagated data over existing data.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.4
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• pp.110-115
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• 2017

This research was performed to investigate the mechanical performance of lightweight concrete including phase changing material(Low temperature PCM). Micro capsulised PCM consisted of wax type core and melamine based wall. Also, for PCM of one single kind, paraffin wax was inserted into Vermiculite and the surface was coated with melamine resin. Interfacial polymerization is based on the principle that macromolecule reaction takes place on the surfaces between 1-dodecanol(core material) and water (solvent) to form the wall material. Lightweight concrete has compressive strength of 10 MPa, tensile strength of 1.5 MPa, and oven dried density of 1.0kg/liter which included 10%, 20%, or 30% PCM by weight. To do so, this study fabricated light-weight foamed concrete ($1.0kg/m^3$) in pre-foaming method and mixed it with PCM micro capsule of 1-dodecanol and melamine to examine its physical properties.

• Journal of the Korean Wood Science and Technology
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• v.24 no.2
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• pp.61-70
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• 1996

침엽수재(針葉樹材)(Radiata pine, Pinus radiata)MDF와 활엽수재(闊葉樹材)(Rubber wood, Hevea brasiliensis)MDF 각 1종을 대상으로 MDF를 제조하기 전 원료(原料) 섬유(纖維)의 미세(微細) 구조(構造) 및 내부결합력 시험 후 MDF의 파괴면(破壞面)에서 섬유표면(纖維表面)에 접착제(接着劑)가 도포(塗布)된 형태를 주사전자현미경(走査電子顯微鏡)으로 관찰하였다. 원료 섬유는 침(針) 활엽수재(闊葉樹材) 모두 fiber twisting 및 shrinkage fold 등이 관찰되었다. 침엽수재(針葉樹材)의 경우는 유연벽공부(有緣壁孔部)에서 유연벽공(有緣壁孔)이 없는 부분에 비하여 shrinkage fold의 발생 빈도가 낮고 표면(表面) 박리(剝離)는 가도관(假導管) 중 벽공이 없는 부분에서 관찰되었다. 활엽수재(闊葉樹材) 목섬유(木纖維)는 침엽수재(針葉樹材)와 마찬가지로 shrinkage fold가 관찰되었으나 표면(表面) 박리(剝離)는 거의 관찰되지 않았다. 활엽수(闊葉樹) 섬유(纖維)에서는 벽공의 유무에 따른 shrinkage fold의 차이(差異)가 거의 관찰되지 않았는데 이는 목섬유(木纖維)가 침엽수(針葉樹) 가도관(假導管)보다 작은 단벽공(單壁孔)을 갖기 때문으로 생각된다. 또 방사유세포(放射柔細胞)와 가도관(假導管) 및 목섬유(木纖維)의 박리(剝離) 부분(部分)에는 융기부(隆起部)가 관찰되었다. 내부결합력 시험후 나타난 파괴면을 통하여 접착제 분포를 관찰한 결과 거의 모든 섬유(纖維)들이 접착제(接着劑)로 둘러싸여 있었으며 섬유(纖維)간 접착형태(接着形態)도 매우 다양하였다. 침활엽수재(針闊葉樹材)간에 강도(强度)의 차이는 있었지만 파괴(破壞) 형태(形態)는 큰 차이를 나타내지 않았다. 즉 침활엽수(針闊葉樹) 모두 접착층(接着層)이 아닌 섬유(纖維)에서 파괴(破壞)가 발생하였으며 섬유에서 박리(剝離)된, 세포벽(細胞壁)의 일부가 다른 섬유(纖維)의 표면(表面)에 남아있는 형태와 섬유(纖維) 표면(表面)에서 떨어져 나간 형태로 관찰되었다. 세포 구성이 단순한 침엽수(針葉樹) MDF에 비하여 유세포(柔細胞)와 도관(導管) 및 목섬유(木纖維)의 파편들이 활엽수(闊葉樹) MDF에서는 다양(多樣)하게 분포하였다.

• Korean Journal of Microbiology
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• v.35 no.1
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• pp.13-17
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• 1999

Shigella sonnez is important causes of human enleric infcctions. S. sonnei KNIH104S was isolated from patient of shigellosis in Korea and previously reported. We cloned 1.7 kb BamHI fragment containing the asd gene encoding an aspartate $\beta$-semialdehyde dehydrogenase from chromosomal DNA of S. sonnei KNIH104S. This recombinant plasmid was named as pSAB17. E. coli $\chi$6097, an a d mutant, cannol grow on the LB medium without DL-$\alpha$, $\varepsilon$-diaminopimclic acid (50 pgiml) but E. coli x 6097(pSAB17) can grow on the same medium. We sequenccd the asd gene ol Shigella for the first time. The asd gcne was composed of 1,104 base pairs with ATG initiation codon and TAA termination codon. Sequence comparison of the asd gene exhibited 99.9% nucleolide sequence hornology with that of E. coli. Also, We constructed the balanced-lethal vector using pBluescrip SK(+) and asd gene of S. sonnei KNIH104S.

• Journal of Sensor Science and Technology
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• v.9 no.5
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• pp.334-340
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• 2000

This paper presents the fabrication of a micro electromagnetic flow sensor for the liquid flow rate measurement. The micro electromagnetic flow sensor has some advantages such as a simple structure, no heat generation, a rapid response and no pressure loss. The principle of the micro electromagnetic flow sensor is based on Faraday's law. If conductive fluid passes through a magnetic field, the electromotive force is generated and detected by two electrodes on the wall of the flow channel. The flow sensor consists of two permanent magnets and a silicon flow channel with two electrodes. The dimension of the flow sensor is $9\;mm\;{\times}\;9\;mm\;{\times}\;1\;mm$. The micro flow channel is mainly fabricated by anisotropic etching of two silicon wafers, and the detection electrodes are fabricated by metal evaporation process. The characteristic of the fabricated flow sensor is obtained experimentally. When the flow rates of water with the conductance of $100-200\;{\mu}S/cm$ are 9.1 ml/min and 62 ml/min, the generated electromotive forces are $261\;{\mu}V$ and 7.3 mV, respectively.

• Journal of Korean Society of Disaster and Security
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• v.10 no.1
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• pp.19-27
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• 2017

In recent years, ground subsidence has been frequently occurred by underground cavities due to the excessive groundwater inflow, caused by poor construction and management, during tunnel excavation and underground structure construction. In this study, a numerical model (SEEFLOW3D) was developed to estimate groundwater fluctuations for saturated-unsaturated poros media, evaluates the impact on ground excavation with open cut and non-open cut scenarios. In addition, the visual MODFLOW was applied to demonstrate the verification of the model compared with both results. Our results indicated that the RMSE and NRMSE was obtained to range over -3.95~5.7% and 0.56~4.62%, respectively. The developed model was expected to estimate groundwater discharges and apply analysis tool for optimum design of waterproof wall in future.