Physiological effects of various light spectra on oxidative stress by starvation in olive flounder, Paralichthys olivaceus

최철영,최지용,Young Jae Choi,Jin-Hyung Yoo 대한독성 유전단백체 학회 2018 Molecular & cellular toxicology Vol.14 No.4

Backgrounds: The present study investigated the effects of different light wavelengths on starvation-induced oxidative stress and apoptosis in olive flounder, Paralichthys olivaceus, by using light-emitting diodes (LEDs; blue, green, and red) at two intensities (0.3 and 0.6 W/m2) for 9 days. Methods: We measured the expression and concentration of antioxidant enzymes, the levels of H2O2, lipid peroxidation (LPO), aspartate aminotransferase (AspAT), alanine aminotransferase (AlaAT) and apoptosis (levels of caspase-3) and DNA damage in olive flounder under experimental conditions. Results: All parameters except the apaotosis parameter significantly increased by starvation and significantly decreased after exposure to green and blue light compared to white fluorescent light. Likewise, both caspase-3 and DNA damage increased due to starvation- induced oxidative stress, and green wavelength irradiation played a role in preventing this stress. Conclusion: These results suggest that green and blue wavelengths can inhibit oxidative stress and apoptosis in starved olive flounder and that green light is particularly efficient for this. Furthermore, the irradiation of green wavelength can play a role in protecting against starvation stress.

은어, Plecoglossus altivelis 난소에서 발현하는 Connexin 35 cDNA의 해석

최철영,장영진,Choi, Cheol-Young,Chang, Young-Jin 한국수산과학회 2000 한국수산과학회지 Vol.33 No.6

기존의 Cx 배열을 참고로 종내${cdot}$종간을 통하여 잘 보존되어져 있는 영역에서 primer를 설계하고, 은어의 난소를 재료로 하여 PCR을 실시하였다. 증폭된 cDNA 단편을 이용하여, 5'RACE 및 3'RACE법에 의해 미지의 영역을 cloning하여 난소에서 발현하는 Cx cDNA의 전염기배열을 결정하였다. 기존의 Cx 배열과 상동성을 비교한 결과, 대서양산 민어의 Cx32.7과 $63.8{\%}$, bovine의 Cx44와 $61.6{\%}$ 및 대서양산 민어의 Cx32.2와는 $56.7{\%}$의 상동성이 나타났다. 본 cDNA는 35,028 Da의 분자량을 code하는 open reading frame (ORF)으로 구성되어 있어, 은어 Cx35로 명명되었다. 또한 아미노산 배열의 친수성${\cdot}$소수성 영역의 분포예측 결과, 4곳의 소수성 영역과 4곳의 친수성 영역을 교차하는 전형적인 Cx의 구조와 일치하였으며, Cx family의 공통${\cdot}$필수적인 배열인 제1세포외 domain의 consensus 배열 및 제2세포외 domain의 consensus 배열도 존재하였다. Mixed primers based on the high sequence homology of selected regions of known connexins (Cxs) was used for PCR reaction. A full-length connexin cDNA of sweetfish (Plecoglossus altivelis) was cloned by rapid amplification of cDNA 5'and (5'RACE) and 3'RACE method. When compared to other known Cx sequences, homology of sweetfish Cx cDNA to Atlantic croaker, Mycropogonias undulatus Cx32.7, bovine, Bos taurus Cx44 and Atlantic croaker Cx32.2 were $63.8{\%},\;61.6{\%}\;and\;56.7{\%}$, respectively. This cDNA encoded 308 amino acids (35,028 dalton) and named as sweetfish Cx35. Hydropathicity analysis of predicted amino acid sequences indicated that sweetfish Cx35 have four major hydrophobic regions and four major hydrophilic regions, suggesting its topology is similar to that of known Cxs. The presence of a tfical Cx consensus sequences were identified in each of the extracellular loops (first loop and second loop).

원자력간 현미경을 이용한 TRIP강 저항 점용접부의 미세조직 분석에 관한 연구

최철영,지창욱,남대근,장재호,김순국,박영도,Choi, Chul Young,Ji, ChangWook,Nam, Dae-Geun,Jang, Jaeho,Kim, Soon Kook,Park, Yeong-Do 대한용접접합학회 2013 대한용접·접합학회지 Vol.31 No.1

The spot welds of Transformation Induced Plasticity (TRIP) steels are prone to interfacial failure and narrow welding current range. Hard microstructures in weld metal and heat affected zone arenormally considered as one of the main reason to accelerate the interfacial failure mode. There fore, detailed observation of weld microstructure for TRIP steels should be made to ensure better weld quality. However, it is difficult to characterize the microstructure, which has similar color, size, and shape using the optical or electron microscopy. The atomic force microscope (AFM) can help to analyze microstructure by using different energy levels for different surface roughness. In this study, the microstructures of resistance spot welds for AHSS are analyzed by using AFM with measuring the differences in average surface roughness. It has been possible to identify the different phases and their topographic characteristics and to study their morphology using atomic force microscopy in resistance spot weld TRIP steels. The systematic topographic study for each region of weldments confirmed the presence of different microstructures with height of 350nm for martensite, 250nm for bainite, and 150nm for ferrite, respectively.

TMCP강의 용접 공정별 입열량에 따른 용접부 물성 평가 및 비교

최철영,지창욱,김형찬,남대근,김정돈,김순국,박영도,Choi, Chul Young,Ji, Chang Wook,Kim, Hyoung Chan,Nam, Dae-Geun,Kim, Joungdon,Kim, Soon Kook,Park, Yeong-Do 대한용접접합학회 2014 대한용접·접합학회지 Vol.32 No.1

This paper has an aim to evaluate microstructure and fracture toughness of TMCP steel weldment applied for off-shore wind tower with the focus on the effect of heat input on the weldment with various welding processes; FCAW(13kJ/cm and 30kJ/cm), SAW(62kJ/cm), and EGW(177kJ/cm). Based on experimental results developed from this study, it was found that the impact toughness of top side for TMCP steel weldments with heat input up to 62 kJ/cm satisfied the required minimum value except the EGW(177kJ/cm). The heat input and microstructure are the main factors of impact toughness. The heat input of 13kJ/cm on back side with low heat input increased the amount of grain boundary ferrite which has low impact toughness, and heat input of 177kJ/cm on top side is significant enough to produce the austenite grain growth. The compositions and sizes of inclusions which are the dominant factors for the formation of acicular ferrite were analyzed by OM and EDS. As the heat input increased, the inclusions also grew and a nucleation site decreased. The size of nonmetallic inclusions and the crack width was nearly similar, therefore the inclusions were related with the crack propagation.

접착제 경화시점에 따른 하이브리드 접합 파단모드 및 접합강도 평가

최철영,최원호,김준기,김종훈,박영도,Choi, Chul-Young,Saha, Dulal Chandra,Choi, Won-Ho,Kim, Jun-Ki,Kim, Jong-Hoon,Park, Yeong-Do 대한용접접합학회 2011 대한용접·접합학회지 Vol.29 No.6

With the development of pre-painted steel sheets for automotive body application, a new joining method is required such as hybrid joining with combination of adhesive bonding and mechanical joining. The objective of this study is to investigate the effect of pre- and post-baking of adhesive bonding on failure mode and strength of hybrid joining of automotive steel sheets. Experiments show that the hybrid joining exhibits better bonding strength and displacement than conventional adhesive joining and mechanical fastening each. Comparison of pre- and post-baked hybrid joining results suggested that baking at $160^{\circ}C$ after mechanical joining was found to have higher joining properties than pre-baking condition. The prebaking condition changed its fracture mode from interfacial to button fracture. The changes in fracture mode with post-baking of hybrid joining was attributed to variation in neck thickness and undercut of joint.

비파괴 계장화 압입시험을 이용한 저항 점용접부 물성 평가

최철영,김준기,홍재근,염종택,박영도,Choi, Chul-Young,Kim, Jun-Ki,Hong, Jae-Keun,Yeom, Jong-Taek,Park, Yeong-Do 한국분말야금학회 2011 한국분말재료학회지 (KPMI) Vol.18 No.1

Nondestructive instrumented indentation test is the method to evaluate the mechanical properties by analyzing load - displacement curve when forming indentation on the surface of the specimen within hundreds of micro-indentation depth. Resistance spot welded samples are known to difficult to measure the local mechanical properties due to the combination of microstructural changes with heat input. Particularly, more difficulties arise to evaluate local mechanical properties of resistance spot welds because of having narrow HAZ, as well as dramatic changed in microstructure and hardness properties across the welds. In this study, evaluation of the local mechanical properties of resistance spot welds was carried out using the characterization of Instrumented Indentation testing. Resistance spot welding were performed for 590MPa DP (Dual Phase) steels and 780MPa TRIP (Transformation Induced Plasticity) steels following ISO 18278-2 condition. Mechanical properties of base metal using tensile test and Instrumented Indentation test showed similar results. Also it is possible to measure local mechanical properties of the center of fusion zone, edge of fusion zone, HAZ and base metal regions by using instrumented indentation test. Therefore, measurement of local mechanical properties using instrumented indentation test is efficient, reliable and relatively simple technique to evaluate the tensile strength, yield strength and hardening exponent.

프랙탈 차원을 이용한 단음절 음성의 자$\cdot$모음 분리

최철영,김형순,김재호,손경식,Choi, Chul-Young,Kim, Hyung-Soon,Kim, Jae-Ho,Son, Kyung-Sik 한국음향학회 1994 韓國音響學會誌 Vol.13 No.3

본 논문에서는 음성신호의 프랙탈 차원을 이용하여 한국어 CV(Consonant-Vowel) 단음절에서 자음과 모음을 분리하는 실험을 하였다. 프랙탈 차원은 Minkowski-Bouligand 차원을 사용하였으며, 형태학적 커버링 (morphological covering) 방법을 이용하여 구하였다. 프랙탈 차원의 음성분리에 있어서의 유용성을 조사하기 위하여 프랙탈 차원과 단구간 에너지 각각을 이용한 음성분리 실험과 에너지와 프랙탈 차원을 같이 이용한 음성분리 실험을 하여 그 결과들을 비교하였다. 실험 결과 에너지의 기울기를 사용한 경우는 $88.0\%$의 바른 분리 결과를 보였고, 프랙탈 차원의 기울기를 사용한 경우는 그보다 더 나은 $93.6\%$의 바른 분리 결과를 보였으며, 에너지의 기울기와 프랙탈 차원의 기울기의 곱을 사용한 경우는 $96.1\%$로 가장 높은 바른 분리결과를 나타냈다. 이를 통해 프랙탈 차원이 음성신호의 분리에 있어서 하나의 유용한 파라메타가 될 수 있음을 확인하였다. In this paper, we performed a class of experiments on segmenting consonant and vowel from Korean consonant-vowel (CV) monosyllable data, using the fractal dimension of the speech signals. We chose the Minkowski-Bouligand dimension as the fractal dimension, and computed it using the morphological covering method. In order to examine the usefulness of the fractal dimension in speech segmentation we carried out speech segmentation experiments using the fractal dimension alone, using the short-time energy alone, and using both the fractal dimension and the short-time energy, and compared the results. From the experiments, segmentation accuracy of $96.1\%$ was achieved for the case with using the multiplication of the slope of the fractal dimension and that of the energy, while the segmentation accuracies for the cases with using the slope of either the fractal dimension or energy alone were slightly lower $(93.6\%)$ or much lower $(88.0\%)$ than the above case, respectively. These results indicate that the fractal dimension can be used as a good parameter for speech segmentation.

당뇨병 환자에서 방수흐림의 정량적 분석

최철영,이준용,김준모,박기호,이은정,Chul Young Choi,Jun Yong Lee,Joon Mo KimKi Ho Park,Eun Jung Rhee 대한안과학회 2008 대한안과학회지 Vol.49 No.12

Purpose: We performed quantitative analysis of aqueous flare to evaluate the influence of diabetes mellitus on the flare values reflecting microvascular injuries of the retina. Methods: We compared aqueous flare values of diabetic patients without diabetic retinopathy (80 patients, 160 eyes), with those of normal control group (21 persons, 42 eyes) and diabetic retinopathy patients (20 patients, 40 eyes). The correlation between flare values and the risk factors of diabetic retinopathy was evaluated in diabetic patients without diabetic retinopathy. Results: Flare values were highest in diabetic retinopathy patients, and higher in diabetic patients without diabetic retinopathy than normal control group with statistical significance (p<0.01). Flare values were not significantly correlated with the risk factors of diabetic retinopathy. Conclusions: Microvascular injury appears to be developed in diabetic patients without diabetic retinopathy.

컴퓨터그래픽스 기술을 이용한 효율적인 클레이 룩 애니메이션 제작 공정 구축 사례

최철영(Chul-Young Choi),김기홍(Ki-Hong Kim),최규돈(Kyu-Don Choi),채일진(Kyu-Don Choi) 한국애니메이션학회 2009 애니메이션연구 Vol.5 No.1

아이들뿐 아니라 어른들에게도 변함없이 사랑을 받고 있는 애니메이션의 표현기법들은 과학기술의 발달과 노동력의 가치향상에 의해 제작 방식의 변화가 요구되고 있다. 애니메이션 표현기법 중 클레이를 이용한 스톱모션 애니메이션은 제작기간이 길고 인력의존도가 높다. CG 기술을 도입하여 인력의존도를 낮추고 제작기간을 단축시켜 콘텐츠를 안정적으로 제작하기 위한 방법의 도입이 필요한 실정이다. 하지만 CG 기술만으로는 실사 클레이룩의 감성 도출이 쉽지 않기 때문에 실사 물체와 CG 캐릭터 간의 공간 속 공존을 통한 착시 효과가 필요하다. 클레이 배경 제작과 모션캡처를 적용한 캐릭터 애니메이션을 이용하여 클레이 룩 애니메이션을 만들기 위한 제작 공정을 알아보고 작업 효율을 높이기 위한 기술 개발을 통해 효율적인 애니메이션 제작을 위한 하나의 방향으로 제시하고자 한다. The constant interest and affection that have been shown by not only children but adults brings the issue of the expression techniques in animation that needs changes of production methods along the development of scientific technique and labor value. Stop-motion animation using clay, one of the representative methods of animation, requires long period of time for production and relies on human power as well. It brings us to the fact that it is necessary to come up with another method for a stabilized production of contents by shortening the production period and reducing the dependency of human power by importing Computer Graphics technique. However it is not a simple task to draw the sense of real clay-look animation with Computer graphics technique, and consequently it is very important to get a trick of the eye through coexistence between the real clay objects and Computer Graphics characters in one space. This study suggests an idea for effective animation production with its technique development to increase work efficiency after looking into the manufacturing process of clay-look animation using character animation that’s applied by motion-capture and background of real clay.

법 체제를 통한 한반도 평화연구

최철영(Choi Cheol-Young) 성균관대학교 법학연구소 2005 성균관법학 Vol.17 No.3

Termination of war by conclusion of a peace treaty is one of the typical institutions of international law. The task and function of peace treaty was to achieve a durable accommodation and reconciliation between former enemies, and oblivion and amnesty for the criminals of war. Besides the termination of the armed hostilities and violence, the other main function of a peace treaty is to establish a new order which, regardless of rights or wrong, insured stability, security and tranquility. In case of Korea War, although armed conflicts and violence have been stopped between the parties by the Korea armistice treaty which was concluded in 1953, but there is still no peace treaty for permanent peace and prosperity of Korean nation. Actually, an armistice treaty has in principle no legal bearing on the termination of a state of war and conditions of a peace treaty. Moreover, an armistice treaty can be a obstacle to conclude a 'real' peace treaty. The present time, the state of non-belligerent in Korea does not maintained by Korea Armistice treaty, but the principle of international law such as prohibition of war. So, a legal regime for the durable accommodation and reconciliation between former enemies is needed in Korean peninsula. However, a legal institution for the permanent peace and prosperity of Korean nation should be surpass a 'mere' peace treaty. It means that the new peace regime for Korea Peninsula should be based on a modern peace treaty, which reflect new peace notion including human welfare and good governance. Because, in modern sense of peace, treaties should try to achieve more than the cessation of hostilities. They endeavored to construct a new political order and to restore good neighbor relations and friendship. In Korean peninsula, it even include the frame work for the unification of former South and North enemies. For this reason, a durable state of non-belligerent shall be secured by Inter-Korean basic agreement concluded in 1991 between the two Korea, after that each parties can discuss next step for more close relationship including a low dimension of federation or confederation as a kind of composite State in the process of final Korea unification. In relation to the parties of legal peace regime, although, normally the belligerent powers are the parties to negotiate and conclude a peace treaty, either bilaterally or multi-laterally, States, which had not participated in preceding war, but were at the same time indispensable for the establishment of workable and effective post-war peace regime of the region, may enter into the process of negotiation. However, 'Korean Type Peace Treaty' should be formed two tract of treaty system, such as a "Basic agreement for Korea Peninsula Peace" and a "North East Peace Treaty" which aims at establishing a broad and permanent new peace regime in North-east Asia. In the latter treaty, U.S., China, Russia, and Japan can be parties with the two Koreas, but not be parties of the former agreement, which will be concluded between South and North Korea. The legal regime for a Korea peace deserves to be called a real peace regime only if it eliminates the causes for a future war permanently and it includes a basic agreement for a new beginning in the mutual relationship between South and North Korea toward Korea Unification.