• Journal of the Korean Geotechnical Society
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• v.21 no.5
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• pp.187-196
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• 2005

Since the allowable bearing capacities of piles in weathered/fractured rock are mainly governed by settlement, the load-displacement behavior of pile should be known accurately. To predict pile head settlement at the design stage, the exact understanding of the load-transfer mechanisms is essential. Therefore, in this research, the load-transfer mechanism of drilled shaft socketed into weathered rock was investigated. For the investigation, five cast-in-place concrete piles with diameters of 1,000 mm were socketed into weathered gneiss. The static axial load tests and the load-transfer measurements were performed to examine the axial resistant behavior of the piles. A comprehensive field/laboratory testing program on weathered rock at the Held test sites was also performed to describe the in situ rock mass conditions quantitatively. And then, the effect of rock mass condition on the load transfer mechanism was investigated. The f-w (side shear resistance-displacement) curve of the pile in moderately weathered rock reached to yielding point at a for millimeter displacements, and after yielding point, the rate of resistance increment dramatically decreased. However, the f-w curve in the highly/completely weathered rock did not show the obvious yielding point, and the resistance gradually increased showing the hyperbolic pattern until relatively high displacement (>15 mm). The q-w (end bearing resistance-displacement) curves showed linear response at least until the base displacement of approximately 10 mm, regardless of rock mass conditions.

• New Physics: Sae Mulli
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• v.68 no.12
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• pp.1302-1307
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• 2018

The crystallographic, electrical and magnetic behaviors of magnetite powder in the vicinity of its Verwey transition were investigated in this study. Magnetite was prepared by synthesizing a nanoparticle precursor and then annealing it at $800^{\circ}C$ for 1 h under a dynamic vacuum. Crystallographic and morphology analyses were done by using scanning electron microscope (SEM) and X-ray diffraction (XRD). The electrical and the magnetic properties were examined by using $M{\ddot{o}}ssbauer$ spectroscopy, vibrating sample magnetometer (VSM) and resistivity measurement. Both the magnetic moment and the resistivity showed discontinuous changes at the Verwey transition temperature ($T_V$). The temperature dependence of magnetic anisotropy constant showed a monotonic decrease with increasing temperature, with slight dip near $T_V$. $M{\ddot{o}}ssbauer$ spectra showed the superposition of two sextets, one from the tetrahedral (A) and the other from the octahedral (B) sites. The results revealed that identical charge states existed in the B site at temperatures both above and below $T_V$. A coordination crossover resulted in a transition from an inverse to a normal spinel at or close to $T_V$.

• Journal of Digital Convergence
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• v.16 no.3
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• pp.157-167
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• 2018

The shortage of research in Vietnam port evolvement is uncontroversial although a huge amount of investment is observed to upgrade both quantity and quality. This study examines the port system performance, in the context of spatially concentration ratio, in Southern Vietnam for the period 2007-2016, by using prevailing indicators for spatially concentration assessment including concentration ratios (CR), the Herfindahl-Hirschman index (HHI), the Gini coefficient, the Lorenz curve and shift-share analysis (SSA), a trend of deconcentration is described in Southern Vietnam port system, since the traditional ports to new deep-water ports. Also, driving forces of this shifting would be discussed in detail. Implications from this study would enable not only port administrators, port operators but also shipping lines, cargo owners, logistics service providers to comprehensively understand the growth of the port system in Southern Vietnam.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.3
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• pp.441-451
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• 2002

Recently, Increasing residential-commercial buildings are composed of upper wall and lower frame type. As structural fragility, a large numbers of researchers have tried to develope the efficient analysis methods. But these studies were too theoretical and were not considered the lateral load which was required in analysing the transfer level in addition to being used nonlinear program which was difficult to use for practical design. thus, results of these studies we not appropriate to apply practical design, therefore, in this paper, the procedure of the current design practice were compared with that of used FEM method and presented new modeling method. in particular, an efficient analytical model which can be used in practical design of residential-commercial buildings for vortical and seismic loads was proposed and the usefulness of proposed model was verified.

• Journal of Digital Convergence
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• v.18 no.7
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• pp.37-46
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• 2020

The aim of this research is to analyze the concentration and deconcentration development of cruise ports in the Mediterranean area by utilizing the concentration ratio (CR), the Herfindahl-Hirschman Index (HHI), the Gini coefficient, and shift share analysis (SSA). The results of analysis indicated a concentration trend in the West Mediterranean. The cruise ports located in Venice, Piraeus, Naples and Livrno in Adriatic and East Med region lost cruise passengers, while the those in West Mediterranean gained the passengers and showed the trend of concentration. This paper providing the shifting passengers among cruise ports that indicates the competitiveness of cruise ports for industrial stake holders to better understand the cruise ports such as tourist boards, ship agents, and port agents.

• Journal of the Korean Chemical Society
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• v.20 no.2
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• pp.118-128
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• 1976

The significant structure theory of liquids and the Bragg-Williams approximation of phase transition theory have been applied to the calculation of the thermodynamic properties of p-azoxyanisole which exhibits a liquid crystal phase of the nematic type. The isotropic phase was treated as a normal liquid; and for the nematic phase, in addition to its liquidity, the effect due to the arrangement of molecular-dipoles was considered. The liquidity of the p-azoxyanisole was described by the significant structure theory of liquids, and the Bragg-Williams approximation was used to consider the effect due to the arrangement of molecular-dipoles. The molar volume, vapor pressure, heat capacity at constant pressure, thermal expansion coefficient, compressibility, entropy and enthalpy change at the nematic-isotropic phase transition point, absolute entropy, and absolute Helmholtz free energy were calculated over the temperature range of the nematic and isotropic phases. The calculated results of the thermodynamic properties were compared with the experimental data.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.206-206
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• 2010

정보화 기술이 급속히 발전함에 따라서 보다 많은 양의 data를 전송, 처리, 저장 하게 되면서 이를 처리 할 수 있는 대용량, 고속, 비휘발성의 차세대 메모리의 개발이 요구 되고 있다. 이 중 저항 변화 메모리(ReRAM)는 일반적으로 전이금속산화물을 이용한 MIM 구조로서 적당한 전기 신호를 가하면 저항이 높아서 전도되지 않는 상태(Off state)에서 저항이 낮아져 전도가 가능한 상태(On state)로 바뀌는 메모리 특성을 가진다. ReRAM은 비휘발성 메모리이며 종래의 비휘발성 기억소자인 Flash memory 보다 access time이 $10^5$배 이상 빠르며, 2~5V 이하의 낮은 전압에서 동작이 가능하다. 또한 구조가 간단하여 공정상의 결함을 현저히 줄일 수 있다는 점 등 많은 장점들이 있어서 Flash memory를 대체할 수 있는 유력한 후보로 여겨지고 있다. 저항 변화의 특징을 잘 나타내는 물질에는 $TiO_2$, $Al_2O_3$, $NiO_2$, $HfO_2$, $ZrO_2$등의 많은 전이금속산화물들이 있다. 본 연구에서는 Reactive DC-magnetron Sputtering 방법과 DC-magnetron sputter를 이용하여 Ti를 증착한 후 Oxidation 방법으로 각각 증착한 $TiO_2$박막을 사용하여 저항변화특성을 관찰하였다. $TiO_2$상부에 Atomic Layer Deposition (ALD)를 이용하여 $HfO_2$ 박막을 증착하여 표면처리를 하고, 또한 $TiO_2$에 다른 전이 금속박막 층을 추가 증착하여 저항변화 특성에 접합한 조건을 찾는 연구를 진행하였다. 하부 전극과 상부 전극 물질로는 Si 100 wafer 위에 Pt 또는 TiN을 사용하였다. 저항변화 특성을 평가하기 위해 Agilent E5270B를 이용하여 current-voltage (I-V)를 측정하였다. X-ray Diffraction (XRD)를 이용하여 증착 된 전기금속 박막 물질의 결정성을 관찰했으며, Atomic Force Microscopy (AFM)을 이용하여 증착 된 샘플의 표면을 관찰했다. SEM과 TEM을 통해서는 sample의 미세구조를 확인 하였다.

• (The) Research of the performance art and culture
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• no.39
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• pp.5-30
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• 2019

Gut, Korean shamanist performance, is the archetype of Korean art therapy. It is because gut has the archetype of Korean mind and expresses the archetype in an artistic and therapeutic way. This paper compares and analyzes Gunung-geori of Hwanhaedo-gut and art therapy theories from two perspectives: the range of therapy and the therapeutic principles of performing ways. Gunung-geori aims to solve prolonged conflicts within a family, linking individual problems to family relationship. Such a therapeutic effect of Gunung-geori is well explained through the theory of Bowen's Family Therapy. Also the therapeutic principles that Gunung-geori's performing way are closely related to "transference" of Freud and "putting in the role" in drama therapy.

• Journal of the Korean Society of Radiology
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• v.85 no.1
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• pp.124-137
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• 2024

Malrotation and midgut volvulus are surgical emergencies that commonly occur within the first month of life. The classic symptom is acute bilious vomiting, while nonspecific symptoms such as recurrent abdominal pain may be present in older children. Malrotation can be associated with duodenal obstruction caused by an abnormal peritoneal fibrous band or congenital anomalies, such as an annular pancreas or a preduodenal portal vein. Volvulus can lead to bowel ischemia and a life-threatening condition, thus prompt and accurate diagnosis is crucial. Diagnosis can be made through upper gastrointestinal series, ultrasonography, and CT, with ultrasonography being preferred as a screening tool due to its rapid and accurate diagnosis, without radiation exposure, in children. This pictorial essay discusses the key imaging findings and diagnostic approaches for malrotation and midgut volvulus, as well as diagnostic pitfalls based on actual cases.

• Journal of Food Hygiene and Safety
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• v.2 no.2
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• pp.67-73
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• 1987

Kluyveromyces fragilis로부터 $\beta$-galactosidase의 생성조건과 조효소액의 성질 그리고 당 전이 반응에 의한 oligosaccharide 생성을 조사한 결과 다음과 같은 결과를 얻었다. \circled1 Peptone-Yeast extract 배지에 6% lactose를 첨가하였을 때 최대 효소생산을 보였다. \circled2 0.05 M potassium phosphate buffer (pH 7.0)에서 3% toluene를 첨가하여 37$^{\circ}C$ 5시간 배양하였을 때 K. fragilis로부터 효소가 최대로 추출되었다. \circled3 효소의 최적온도는 4$0^{\circ}C$이고 4$0^{\circ}C$ 이상의 열처리에서는 효소가 파괴되었으며, pH6-7에서는 상당히 안정하였다. \circled4 ONPG 기질로 사용하였을 때 Km 값은 2.5mM이었다. \circled5 당 전이 반응의 결과, 7개의 oligosaccharide가 생성되었다. 이상의 실험결과로 볼 때, 본 실험에 사용한 K. fragilis SKD 7001은 Beta-galactosidase의 생산을 위해서 이용 가치가 인정되었으며, 특히, 이 효소의 활성이 중성 pH에서 강하고 안정한 상태를 보이는 것은 시유나 원료우유의 lactose를 중성에서 해야 한다는 점을 고려할 때, 실용적 가치가 있다고 본다. 또, 이 효소의 작용과정에서 생성되는 oligosacchride는 장내 bifidus균의 생육을 촉진시키는 효과가 인정되고 있기 때문에 이용가치를 더욱 높여주는 것으로 생각된다.