• The Journal of the Korea Contents Association
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• v.16 no.3
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• pp.72-80
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• 2016

There are various methods of developing latent fingerprints from evidence found at crime scenes. Crime scene investigators should choose appropriate techniques among them depending on the conditions of the evidences. In this study, we compared the three methods using forensic light sources to develop latent fingerprints on multi-colored surfaces. We selected the various samples according to color, shape and texture of the surfaces and developed the latent fingerprints using fluorescent powder, IR(Infrared) photography and Episcopic Co-axial Illumination. Fluorescent powder was highly effective on all surfaces. IR photography was also effective, but only on the not dark surfaces. Episcopic Co-axial Illumination was effective only on the flat and polished surfaces. Although fluorescent powder was fine regardless of the characteristics of the surfaces, IR photography was better on certain surfaces.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.668-672
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• 2001

The purpose of study was to measure the interrater reliability of the caries diagnostic instrument, Diagnodent(KaVo, Germany), using a new laser fluorescence technique. Occlusal surfaces and smooth surfaces of one hundred extracted human premolars and molars were examined by four dentists. Pearson correlation coeffcients were 0703 to 0.870 for occlusal surfaces and 0.764 to 0.932 for smooth surfaces (P<0.01, all). Reliability coefficients which were calculated by intraclass correlation coefficients were 0.9450 for occlusal surfaces and 0.9605 for smooth surfaces. Therefore, the interrater reliability of caries diagnosis by Diagnodent is very high, and the rater training would be necessary more for occlusal surfaces than for smooth surfaces.

• Journal of Periodontal and Implant Science
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• v.49 no.5
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• pp.310-318
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• 2019

Purpose: Surface alterations of titanium discs following instrumentation with either a nylon brush or a metal brush were evaluated. Methods: A total of 27 titanium discs with 3 surface types (9 discs for each type), including machined (M) surfaces, sandblasted and acid-etched (SA) surfaces, and surfaces treated by resorbable blast media (RBM), were used. Three discs were instrumented with a nylon brush, another 3 discs were instrumented with a metal brush, and the remaining 3 discs were used as controls for each surface type. Surface properties including the arithmetic mean value of a linear profile (Ra), maximum height of a linear profile (Rz), skewness of the assessed linear profile (Rsk), arithmetic mean height of a surface (Sa), maximum height of a surface (Sz), developed interfacial area ratio (Sdr), skewness of a surface profile (Ssk), and kurtosis of a surface profile (Sku) were measured using confocal microscopy. Results: Instrumentation with the nylon brush increased the Ra, Sa, and Sdr of the M surfaces. On the SA surfaces, Ra, Sa and Sdr decreased after nylon brush use. Meanwhile, the roughness of the RBM surface was not affected by the nylon brush. The use of the metal brush also increased the Ra, Sa, and Sdr of the M surface; however, the increase in Sdr was not statistically significant (P=0.119). The decreases in the Rz, Sz, Ra, Sa, and Sdr of the SA surfaces were remarkable. On the RBM surfaces, the use of the metal brush did not cause changes in Ra and Sa, whereas Rz, Sz, and Sdr were reduced. Conclusions: Titanium surfaces were altered when instrumented either with a nylon brush or a metal brush. Hence, it is recommended that nylon or metal brushes be used with caution in order to avoid damaging the implant fixture/abutment surface.

• Honam Mathematical Journal
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• v.32 no.4
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• pp.777-790
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• 2010

We study surfaces in the 3-dimensional Euclidean space with two family of planar lines of curvature. As a result, we establish some characterization theorems for such surfaces.

• Journal of the Korean Mathematical Society
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• v.55 no.1
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• pp.59-71
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• 2018

In the present paper, we study and classify factorable surfaces in a 3-dimensional isotropic space with constant isotropic Gaussian (K) and mean curvature (H). We provide a non-existence result relating to such surfaces satisfying ${\frac{H}{K}}=const$. Several examples are also illustrated.

• Bulletin of the Korean Mathematical Society
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• v.42 no.1
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• pp.23-27
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• 2005

In this paper, we study rotation surfaces in a Euclidean space with pointwise 1-type Gauss map and obtain by the use of the concept of pointwise finite type Gauss map, a characterization theorem for rotation surfaces of constant mean curvature.

• Bulletin of the Korean Mathematical Society
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• v.46 no.3
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• pp.567-576
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• 2009

We classify and characterize the rational helicoidal surfaces in a three-dimensional Minkowski space satisfying pointwise 1-type like problem on the Gauss map.

• Journal of the Korean Mathematical Society
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• v.36 no.6
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• pp.1091-1113
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• 1999

In this paper, we first classify the possible configurations of fibrations which are not semi-stable on extremal elliptic K3 surfaces. Then we give a complete list of extremal elliptic K3 surfaces whose singular fibers are all not of type $I_n$.

• Communications of the Korean Mathematical Society
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• v.11 no.3
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• pp.797-805
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• 1996

We provide a new proof of the following fact using least area surfaces : If the fundamental group of a $P^2$-irreducible closed 3-manifold M contains a finitely generated nontrivial normal subgroup of infinite index, then M has a finite cover which is a closed surface bundle over $S^1$ , unless N is free.

• Honam Mathematical Journal
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• v.31 no.2
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• pp.177-183
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• 2009

In this article, we study ruled surfaces in a Lorentzian space-time, which have finite type immersion. We give a condition for bi-finite type surfaces to be of finite type.