• Journal of Adhesion and Interface
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• v.19 no.2
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• pp.60-67
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• 2018

In the present study, when the surface of kenaf, which is an environmentally friendly natural fiber, was treated by using adhesive solution containing Chemlok 402, the effects of fiber surface treatment, fiber content and fiber length on the cure characteristics, hardness, tensile modulus and abrasion resistance of kenaf/natural rubber composites were investigated. The kenaf fiber contents consisting of the composites were varied with 0, 5, 10, 15, and 29 phr at a fixed fiber length of 2 mm and also the fiber length was varied with 2, 35, and 70 mm at a fixed fiber content of 5 phr. The Tmax and tc90 values, Shore A hardness, tensile modulus, and abrasion resistance of natural rubber composites strongly depended on the kenaf fiber content and length. The characteristics of the composite with kenaf fibers treated with the adhesive solution containing Chemlok 402 were higher than those untreated. This is ascribed to the improved interfacial adhesion between the treated kenaf fiber and the rubber matrix. This study suggests that an appropriate use of adhesive solution may be possible to increase the properties of natural fiber-reinforced composites.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.4
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• pp.394-404
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• 2006

Statement of problem: A conventional 3-unit fixed partial denture design with a pontic between two retainers is the most commonly used. However in cases where the mental nerve is in close proximity to the second premolar, a cantilever design can be considered. As such, logical and scientific evidence is lacking for the number and position of implants to be placed for partially edentulous patients, and no clear-cut set of treatment principles currently exist. Purpose : The purpose of this study was to evaluate prognosis of implant-supported fixed partial dentures and to compare changes in bone level which may rise due to the different factors. Material and method : The present study examined radiographical marginal bone loss in patients treated with implant-supported fixed partial dentures (87 prostheses supported by 227 implants) and evaluated the influence of the span of the pontic, type of the opposing dentition. Clinical complications were studied using a retrospective method. Within the limitation of this study. the following result were drawn Result, 1. Seven of a total of 227 implants restored with fixed prostheses failed, resulting in a 96.9% success rate. 2. Complications encountered during recall appointments included dissolution of temporary luting agent (17 cases), porcelain fracture (8 cases), loosened screws (5 cases), gingival recession (4 cases), and gingival enlargement (1 case). 3. Marginal bone loss, 1 year after prosthesis placement, was significant(P<0.05) in the group that underwent bone grafting, however no difference in annual resorption rate was observed afterwards. 4. Marginal bono loss, 1 year post-placement, was greater in cantilever-type prostheses than in centric pontic protheses (P<0.05). 5. Marginal bone loss was more pronounced in posterior regions compared to anterior regions (P<0.05). 6. The degree of marginal bone loss was proportional to the length of the pontic (P<0.05). Conclusion: The success rate of implant-supported fixed partial dentures, including marginal bone loss, was satisfactory in the present study. Factors influencing marginal bone loss included whether bone graft was performed, location of the pontic (s), location of the surgical area in the arch pontic span. Long-term evaluation is necessary for implant-supported fixed partial dentures, as are further studies on the relationship between functional load and the number of implants to be placed.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.42
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• pp.163-186
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• 2009

On April 11, 1980, the "United Nations on Contracts for the International Sale of Goods" ("CISG") was prepared by the United Nations Commission on International Trade Law (UNCITRAL) and approved by a diplomatic conference in Vienna providing uniform law for international sales of goods. It took effect as of March 1, 2005, in Korea. It is set forth on the seller's remedies for breach by the buyer Section III (Art. 61 - 65) under the CISG. In this study, the focus is only on the seller's notice fixing additional final period for performance (Art. 63) and the right to avoid the contract (Art. 64), with examination on some relevant foreign arbitral awards rendered by the ICC and the CIETAC together. Article 63 provides that the seller may fix an additional period of time for reasonable length for performance by the buyer of his obligation. It was found from the above arbitral awards that the concept of 'reasonable length' should be decided on a case-by-case basis, given the specific circumstances in the case [Art. 63(1)]. It is provided that unless the seller has received a notice that he will not perform within the period so fixed, the seller may not, during that period, resort to any remedy for breach of contract in accordance with Article 63(2). Article 64(1) provides the means and grounds for avoidance of the contract, which can be avoided 1) when the breach of the buyer amounts to a fundamental breach of contract, or 2) when the additional period of time is fixed by the seller, unless the buyer declares that he will not perform so within the period of fixed time. As we examined in the above arbitral awards, it was held that the contract is avoided when the seller sends the final notice stating that he will avoid the contract, after the expiration of the additional period of time fixed by the seller in the ICC award. On the contrary, it was held that the contract should be deemed to be avoided exactly when the expiration of additional period noted in the avoidance notice is elapsed in the CIETAC award. Article 64(2) sets time limits for avoidance.

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.9-13
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• 1998

Visual system of Korean Salamander(Hynobius leechi) was morphologically studied. Fertilized eggs in egg sacs were collected and were developed in sterile saline solution. Various sized larvae of 5-30mm in length were fixed. Specimens were paraffin sectioned and were observed under light microscope. In 5mm length larva, lens rudiment induced by optic cup was combined with sensory ectoderm. The shape of lens was changed as spherical in 12mm length larva, but the retinal layer did not differentiated into three layers. The differentiation of retinal layer was clear in 14-16mm length larva. The central region of lens fibers was degenerated. Iris and ciliary body were formed from the marginal zone of optic cup in 20mm length larva. Choroid was thicker in elder eye of 30mm length larva and cartilage developed at outer region of optic cup. The outer segment of photoreceptor cell layer grew longitudinally. Optic nerve was connected to the ventral part of brain through cartilage.

• Korean Journal of Poultry Science
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• v.22 no.1
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• pp.1-6
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• 1995

A total of 514 birds were used to investigate the influence of body weight and shank length at hatch on the body weights at various ages in growing pheasant. Statistical model included the terms of hatch and sex as fixed effects and the two covariates of body weight and shank length at hatch. In this model, the effects of hatch and sex on the body weights at the age of 4, 8, 12, 16 and 20 wk, and the average daily gains from hatch to 8 wk and from 8 to 16 wk of age were highly significant(P<0.01). All the regression coefficients of body weights and average daily gains on the body weight at hatch were also significant(P<0.01). Their estimates were 3.05.7.21. 13.89, 15.18 and 15.33 for the body weights at 4. 8, 12, 16 and 20 wk of age ; 0.111 and 0.142 for the average daily gains from hatch to 8 wk, and from 8 to 16 wk of age, respectively. On the shank length, only the regression coefficients of the body weights at 4 and 8 wk of age and the average daily gains from hatch to 8 wk of age were significant(P<0.01). Results of this study suggest that body weight at hatch do significantly affect the body weights in the growing periods up to' the 20 wk of age, but the shank length at hatch influences the body weights only at early age.1)

• Journal of Advanced Navigation Technology
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• v.24 no.6
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• pp.540-548
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• 2020

In this paper, the performances of virtual reference station (VRS) and flächen korrektur parameter (FKP) based Network real time kinematics (RTK) according to baseline length were compared and analyzed. We applied the VRS and FKP corrections for each baseline length obtained from National Geographic Information Institute Network RTK services to an FKP-supported commercial receiver and analyzed the RTK results in the range and position domains. In the case of VRS, RTK performance was degraded due to the spatial error, which increase in proportion of the baseline length. On the other hand, FKP compensates for spatial errors by using the gradients of dispersive and non-dispersive errors, so it showed stable RTK performance compared to VRS even if the baseline length increases up to 130 km. However, in the case of long baseline of 150 km or more, integer ambiguities were incorrectly fixed due to the decrease in the performance of the FKP corrections.

• Electronics and Telecommunications Trends
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• v.8 no.2
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• pp.69-91
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• 1993

In the conventional speech processing, the technique of FFT(Fast Fourier Transform) is usually applied to the finite number of samples within the window of specified length using the fixed sampling rate. In this case, the temporal resolution is dependent upon the length of window while the spectral resolution is dependent upon the number of samples within the window. Thus, once the temporal resolution is determined the spectral resolution is also determined or vice versa. To resolve this type of dilemma, a new type of bank-filter similar to the characteristics of cochlear model needs to be considered. Furthermore, wide dynamic range of cochlea certainly helps the stable extraction of speech features. In the paper, the human auditory system will be briefly introduced and previous works on auditory preprocessors based on cochlear model will be reviewed. As a conclusion, the design considerations of auditory preprocessors based on cochlear model will be addressed.

• Journal of Information Processing Systems
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• v.12 no.2
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• pp.322-331
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• 2016

Image compression is an essential technique for saving time and storage space for the gigantic amount of data generated by images. This paper introduces an adaptive source-mapping scheme that greatly improves bit-level lossless grayscale image compression. In the proposed mapping scheme, the frequency of occurrence of each symbol in the original image is computed. According to their corresponding frequencies, these symbols are sorted in descending order. Based on this order, each symbol is replaced by an 8-bit weighted fixed-length code. This replacement will generate an equivalent binary source with an increased length of successive identical symbols (0s or 1s). Different experiments using Lempel-Ziv lossless image compression algorithms have been conducted on the generated binary source. Results show that the newly proposed mapping scheme achieves some dramatic improvements in regards to compression ratios.

• Journal of the Korea Convergence Society
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• v.7 no.4
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• pp.181-190
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• 2016

The objective of this study is to find the effective stiffness and compressive strengths of a unit-cell pinwheel truss and double pinwheel truss model designed following a double helical geometry similar to that of the DNA (deoxyribonucleic acid) structure in biology. The ideal solution for their derived relative density is correlated with a ratio of the truss thickness and length. To validate the relative stiffness or relative strength, ABAQUS software is used for the computational model analysis on five models having a different size of truss diameter from 1mm to 5mm. Applied material properties are stainless steel type 304. The boundary conditions applied were fixed bottom and 5 mm downward displacement. It was assumed that the width, length, and height are all equal. Consequently, it is found that the truss model has a lower effective stiffness and a lower effective yielding strength.

• Journal of The Korean Astronomical Society
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• v.27 no.1
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• pp.13-29
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• 1994

We have constructed a 3-dim hydrodynamics code called BTSPH. The fluid dynamics part of the code is based on the smoothed particle hydrodynamics (SPH), and for its Poisson solver the binary tree (BT) scheme is employed. We let the smoothing length in the SPH algorithm vary with space and time, so that resolution of the calculation is considerably enhanced over the version of SPH with fixed smoothing length. The binary tree scheme calculates the gravitational force at a point by collecting the monopole forces from neighboring particles and the multipole forces from aggregates of distant particles. The BTSPH is free from geometric constraints, does not rely on grids, and needs arrays of moderate size. With the code we have run the following set of test calculations: one-dim shock tube, adiabatic collapse of an isothermal cloud, small oscillation of an equilibrium polytrope of index 3/2, and tidal encounter of the polytrope and a point mass perturber. Results of the tests confirmed the code performance.