• The Korean Journal of Ecology
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• v.10 no.3
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• pp.151-159
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• 1987

Relationships between soil factors and the growth of annual ring of Pinus densiflora grown on stony mountain were investigated at two sites of the different parent rocks: the one was formed by granite at Mt. Gwanag, Seoul and the other feldspar porphyry at Mt. Bipa, Daegu. The growth of annual ring was influenced by the physical factors of soil, such as soil depth, field caacity and water content of soil, rather than by the KDICical factors, such as total nitrogen, potassium, and calcium of soil. Of the soil factors affecting the growth of annual ring, soil depth, field capacity, water content of soil and organic matter closely interrelated with each other. All of these factors influenced water content of soil which might affect the water potential of Pinus densiflora leaves. In fact, the leaf water potential, affecting as the main factor for the growth of annual ring, of the pine grown in a deep soil was higher than that of the pine in a shallow soil.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.144-145
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• 2005

In this study, we have developed the high resolution multichannel seismic data acquisition system and shallow marine seismic source. It is easy to operate our source system which utilizes piezoelectric transducer of high electrical power. According to water depth, survey condition and purpose, transducer number of source system can be easily changed in order to maximize field applicability. In the recording part, we used 24 bits and 8 channel high speed A/D board in order to achieve the improvement of data quality and the efficiency of data acquisition. The developed system was tested and varied with the data acquisition parameters such as source-receiver offset, and transducer number versus water depth for the field application.

• Special Issue of the Society of Naval Architects of Korea
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• 2006.09a
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• pp.71-76
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• 2006

Preliminary conceptual design of hulls is developed and a theoretical evaluation study performed for the comparison of the hull concepts. Systematic variation of the side hull location is carried out to find an optimum position of side hulls for a trimaran by CFD computation. In order to compare computed results, the model test of trimaran was carried out. Shallow water effect is considered due to the route which has critical water depth of 20m for the design speed and investigated on the condition of different speeds and water depth by the numerical computations.

• Ocean and Polar Research
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• v.25 no.4
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• pp.437-446
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• 2003

Field measurements of directional waves were carried out during the summer of 2002 at two coastal sites in water of finite depth. A couple of general purpose instruments were used employing acoustic Doppler technology. The aim of the study was to investigate the spatial behavior of the directional movement of waves as they come ashore. In total,74 tests were carried out during which sea states of low to moderate intensity were recorded. A great number of these runs displayed bimodal characteristics of the spreading function at high frequencies. It was found that in general, the frequency-integrated directional width tends to broaden as the water shoals and when refraction effects are negligible. This is attributed to wave-wave interactions that become pronounced in shallow water. The same directional width showed, also, a tendency to increase with increasing peak frequency of the sea state spectrum. The behavior of the kurtosis of the spreading function was also examined. It was found that for higher frequencies this index tends to increase in wave spectra above a certain sea severity threshold.

• The Journal of the Acoustical Society of Korea
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• v.15 no.2
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• pp.101-104
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• 1996

The pressure field for the Pekeris model which is consisted of a surface layer of fresh water overlying a thick (essentially semi-infinite) bottom layer of coarse sand is investigated experimentally in a anechoic tank scaled down 1/1,000. The water depth and frequency have been controlled so that the continuous mode integrand has not a resonance close to cut-off, and the experimental results relatively well agree with the theory which is represented as the sum of the discrete modes over a range about 10 times the water depth.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.5 no.2
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• pp.91-98
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• 1993

A two-dimensional turbulence model for the surface discharge of heated water into cross-flow field has been developed. The depth-averaged continuity, momentum and temperature equations, are solved by an efficient finite-difference procedure known as SIMPLE. Turbulent stresses and heat fluxes are determined from a depth-averaged version of the $textsc{k}$-$\varepsilon$ equation. Results of test run clearly demonstrate its effectiveness in handling strong turbulent phenomena in very shallow near-field region.

• Journal of the Optical Society of Korea
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• v.18 no.2
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• pp.151-155
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• 2014

Although various ophthalmic imaging methods, including fundus photography and optical coherence tomography, have been applied for effective diagnosis of ocular diseases with high spatial resolution, most of them are limited by shallow imaging penetration depth and a narrow field of view. Also, many of those imaging modalities are optimized to provide microscopic anatomical information, while functional or cellular information is lacking. Compared to other ocular imaging modalities, photoacoustic imaging can achieve relatively deep penetration depth and provide more detailed functional and cellular data based on photoacoustic signal generation from endogenous contrast agents such as hemoglobin and melanin. In this paper, array-based ultrasound and photoacoustic imaging was demonstrated to visualize pigmentation in the eye as well as overall ocular structure. Fresh porcine eyes were visualized using a real-time ultrasound micro-imaging system and an imaging probe supporting laser pulse delivery. In addition, limited photoacoustic imaging field of view was improved by an imaging probe tilting method, enabling visualization of most regions of the retina covered in the ultrasound imaging.

• Journal of Species Research
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• v.9 no.4
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• pp.473-479
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• 2020

In this study, we briefly describe five newly recorded foraminiferal species from off the southern coast of Jeju Island: Ammolagena clavata, Neoeponides bradyi, Nodosaria lamnulifera, Rhabdammina abyssorum, and Uvigerina schwageri. Ammolagena clavata and Rhabdammina abyssorum are the first reports of the genera Ammolagena and Rhabdammina in Korea. In addition, R. abyssorum is reported from a depth of 103 m, which is a relatively shallow record within the distribution depth range for this agglutinated deep-sea species. Ammolagena clavata also shows interesting characteristics that the test usually attaches to substrates including shell fragments, sediment particles, or other foraminiferal tests. All other three species have typical calcareous and hyaline tests. The present report on unrecorded species improves the understanding of foraminiferal species diversity in Korean waters and confirms the need for the further research on foraminifera in the adjacent seas of Korea.

• Vacuum Magazine
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• v.2 no.2
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• pp.17-23
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• 2015

Medium Energy Ion Scattering (MEIS) has been successfully used for ultrathin film analysis such as gate oxides and multilayers due to its single atomic depth resolution in compostional and structural depth profiling. Recently, we developed a time-of-flight (TOF) MEIS for the first time, which can analyze a $10{\mu}m$ small spot. Small spot analysis would be useful for test pattern analysis in semiconductor industry and various thin film technology. The ion beam damage problem is minimized due to its improved collection efficiency by orders of magnitude and the ion beam neutralization problem is removed completely for quantitative analysis. Newly developed TOF-MEIS has been applied for gate oxides, ultra shallow junctions, nanoparticles, FINFET structures to provide compositional and structural profiles. Further development for submicron spot analysis and applications for functional nano thin films and nanostructured materials are expected for various nanotechnology and biotehnology.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.733-742
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• 2020

Taking the cylindrical float of the floating fence of a floating litter collection device as the research object, based on the shallow immersion characteristics of the cylindrical float, the Morison equation is modified, and the interaction between regular waves and the partially immersed horizontal cylindrical float is discussed in combination with scale model test. The results show that the modified Morison equation can accurately predict the wave force of the horizontal cylindrical float and reveal the influence of amplitude, immersion depth and period on the wave force of the cylindrical float. For partially immersed cylindrical floats, the wave force increases with the increase in wave height and decays with the increase in period. The positive value distribution of the wave force is larger than that of the negative direction, and the difference between the positive and negative directions is mainly affected by the immersion depth.