• 한국표면공학회지
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• 제38권6호
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• pp.227-233
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• 2005

Electrochemical characteristics of welded stainless steels containing Ti have been studied by using the electrochemical techniques in 0.5 M $H_2SO_4$+0.01 M KSCN solutions at $25^{\circ}C$. Stainless steels with 12 mm thick-ness containing $0.2{\~}0.9 wt\%$ Ti were fabricated with vacuum melting and following rolling process. The stainless steels were solutionized for 1hr at $1050^{\circ}C$ and welded by MIG method. Samples were individually prepared with welded zone, heat affected zone, and matrix for intergranular corrosion and pitting test. Optical microscope, XRD and SEM are used for analysing microstructure, surface and corrosion morphology of the stainless steels. The welded zone of the stainless steel with lower Ti content have shown dendrite structure mixed with $\gamma$ and $\delta$ phase. The Cr-carbides were precipitated at twin and grain boundary in heat affected zone of the steel and also the matrix had the typical solutionized structure. The result of electrochemical measurements showed that the corrosion potential of welded stainless steel were Increased with higher Ti content. On the other hand, reactivation($I_r$), passivation and active current($I_a$) density were decreased with higher Ti content. In the case of lower Ti content, the corrosion attack of welded stainless steel was remarkably occurred along intergranular boundary and ${\gamma}/{\delta}$ phase boundary in heat affected zone.

• 아동학회지
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• 제33권1호
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• pp.41-62
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• 2012

This study explored the case of sandplay therapy for a 4th grade girl suffering from selective mutism. Her selective mutism apparently began following an extremely embarrassing experience in kindergarten. Her symptoms were a combination of symbiotic, reactive and passive- aggressive type behaviors. The goal of the therapy undertaken with this child was to enable her to express her repression and suppression, within a free and protective space during sandplay therapy. There were a total of 60 sessions of sandplay therapy. The client described the situations she had experienced in the first sandtray, by placing babies absent caring adults and food on the sandbox. She also placed baby fish away from their mother. In the mid-point of the sessions, she repeated her regressive behaviors by babbling like a baby and fought with snakes and monsters. In the final sessions, she showed integration and adaptation by engaging in snow play, expressing the union of opposites, placing blue and red mig and making a cross on the sand. This study showed the effectiveness of sandplay therapy since her selective mutism was lessened.

• 대한산업공학회지
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• 제29권3호
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• pp.247-252
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• 2003

We propose an approximation of the M/G/1 system with finite workload capacity, where those customers whose admission to the system would increase the workload beyond a prespecified finite capacity limit are not accepted. Our approximation method is based on the idea that the service time of a customer in the M/G/1 system can be approximated as the sum of service times of a batch of customers in the $M^X/d/1$ system where the deterministic service time d is small enough. That is, the original service time is discretized and approximated by the batch size. We exemplified our method by obtaining the average workload of the M/M/1 system by means of the $M^X/d/1$ system, where the batch size is geometric. In addition, the approximate blocking probabilities of the M/M/1 and $M/E_k/1$ system with finite workload capacities are sought. The proposed method turns out to give a good approximation, which is compared with a simulation.

• 미생물학회지
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• 제22권4호
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• pp.215-222
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• 1984

Rhodotorula gl$\varkappa$tinis 세포벽에 작용하는 용해 효소 생산곰팡이를 토양으로부터 분리하였고, Aspergillus f'||'&'||'micro;mig$\alpha$tus에 속하는 species로 동정되었다. 이 세포벽 용해효소는 세표외 유도효소였으며 lytic polysaccharidase 와 protease로 구성되어 생세포 용해에 공동으로 착용하였다. 이 lytic polysaccharidase는 Ascomycetous 효모에서의 주 구성 결합인 ${\beta}-1,3-$와 ${\beta}-1$, 6-glucan에는 작용치 않았다. 이 효소는 생세포에는 역가가 낮았지만 R. glutinis의 분획된 세포액에는 protease의 도움없이 작용할 수 있었다.

• Journal of Welding and Joining
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• 제34권4호
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• pp.34-39
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• 2016

Recently, aluminum alloy has used various industry, such as automobile, shipbuilding and aircraft because of characteristics of low density and high corrosion resistance. Al 6061-T6 is heat treatment materials so it has high strength and mostly used for assembly by mechanical fastening such as a bolting and riveting. In GMA (Gas Metal Arc) welding of alloy, some defects which are hot cracking, porosity, low-mechanical properties and large heat affected zone is generated, because of high heat conductivity. It reduces mechanical properties. In this study, the major factor effected on properties are analyzed after welding in Al 6061-T6 in GMAW, then optimize heat treatment conditions. Plate of Al 6061-T6 with a thickness of 12 mm is welded in V groove and applied welding method is butt joint. Mechanical properties and microstructure are analyzed according to heat treatment condition. Tensile strength, microstructure and Hardness are evaluated. Result of research appears that Al 6061-T6 applied heat treatment show outstanding mechanical properties.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.783-788
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• 2003

In this paper, we present a new approach to detect and recognize human face in the image from vision camera equipped on the mobile robot platform. Due to the mobility of camera platform, obtained facial image is small and pose-various. For this condition, new algorithm should cope with these constraints and can detect and recognize face in nearly real time. In detection step, ‘coarse to fine’ detection strategy is used. Firstly, region boundary including face is roughly located by dual ellipse templates of facial color and on this region, the locations of three main facial features- two eyes and mouth-are estimated. For this, simplified facial feature maps using characteristic chrominance are made out and candidate pixels are segmented as eye or mouth pixels group. These candidate facial features are verified whether the length and orientation of feature pairs are suitable for face geometry. In recognition step, pseudo-convex hull area of gray face image is defined which area includes feature triangle connecting two eyes and mouth. And random lattice line set are composed and laid on this convex hull area, and then 2D appearance of this area is represented. From these procedures, facial information of detected face is obtained and face DB images are similarly processed for each person class. Based on facial information of these areas, distance measure of match of lattice lines is calculated and face image is recognized using this measure as a classifier. This proposed detection and recognition algorithms overcome the constraints of previous approach [15], make real-time face detection and recognition possible, and guarantee the correct recognition irregardless of some pose variation of face. The usefulness at mobile robot application is demonstrated.

• Journal of Advanced Marine Engineering and Technology
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• 제41권1호
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• pp.21-30
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• 2017

현재 국내에서 공장 보수용접이 가장 많이 이루어지고 있는 선박 엔진 부품은 피스톤 크라운과 배기밸브이다. 또한 선박 엔진 밸브와 크랭크 축 등의 경우에는 신규 부품에서도 성능향상을 위해 표면개질방법으로 오버레이 용접이 시공되고 있다. 용착률을 높이는 고능률 오버레이 용접 공정으로 Hot Wire GTAW, Cold Tandem GMAW, Band Arc SAW, Tandem SAW법이 개발되어 있고, 용사방법으로 PTA공정이 현장에서 많이 시공되고 있다. 입열량 제어가 용이한 공정으로 GMAW-Pulse, CMT 용접공정이 있다. 엔진 배기밸브의 보수를 위한 오버레이공정에서 열영향부에 가까운 모재 내에 액화균열이 발생하는 경우가 있어 주의를 요한다. GMAW-Pulse 공정과 CMT공정에서는 입열량 제어가 용이하여 높은 용착속도를 유지하면서도 액화균열의 발생 없이 엔진 밸브의 보수 또는 표면 개질 목적으로 시공이 가능하다. 최근에 국내에서 고능률 용접 공정으로 선박엔진의 보수 또는 표면 개질 목적으로 사용 가능한 Super-TIG 용접공정이 개발되어 있다. 이 공정은 아크를 플라즈마 스트림이라고 보고 전류증가에 따라 커지는 아크압력을 막으면서도 용가재의 용융 효율이 극대화 되도록 폭이 큰 C형의 오목한 용가재를 발명하여 용착률을 획기적으로 향상시킨 용접공정이다.

• 한국식품영양학회지
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• 제11권4호
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• pp.437-443
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• 1998

This research is to establish the basic data of the nutritive value and improve our diet. In the part of the leaf and stem of the wild and cultivated horned rampion (Phyteuma japonicum Mig), the components such as chemical compositon, vitamin C, free sugar, mineral, nucleotide and its related compounds, composition and free amino acid were analyzed one after another. Content of the crude lipids and proteins was determined much higher in its wildness than in its cultivated horned rampion; while, that of carbohydrates was higher in the former than in the latter. The content of vitamin C was retained higher in the leaf than in the stem horned rampion. And the content of calcium among the detected minerals was outstanding in all of the samples collected, and potassium and magnesium was the next ones in its order. The main components of free sugars in both the wild and cultivated horned rampion were glucose and fructose, and their content was higher in the stem than in the leaf. Nucleotide and its related compounds were identified with 5 kinds of nucieotides such as CMP, UMP, IMP, AMP and hypoxanthine (Hx), and the content of Hx and AMP was the highest I the wild and cultivated samples, respectively. In the composition amino acid of the wild horned rampion, glutamic acid, aspartic acid and phenylalanine was outstandingly abundant; while, such amino acid as methinone and proline was small and besides cysteine couldn't be detected in the stem. Total amounts of composition amino acid in the leaf was 2118.0 and 1120.1mg% in the wild and cultivated sample, respectively. In the free amino acid of horned rampion, the total amount ranged from 8.5 to 50.1mg.%, which were lower level than that of composition amino acid. But the number of free amino acid was 29 kinds, which was bigger in its number than that of composition amino acid detected 17 kinds.

• Journal of Welding and Joining
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• 제34권5호
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• pp.70-76
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• 2016

In this study, Microstructure and tensile properties in arc brazed joints of 1000MPa grade DP steel using Cu-Si insert metal were investigated. The fusion zone was composed of Cu phase which solidified a little Fe and Si. The former phase formed due to dilute the edge of base material by arc, although Fe was not solid solution in Cu at the room temperature. Cu3Si particles formed by crystallization at $1100^{\circ}C$ during faster cooling. After the tensile shear test, there are no differences between the brazed joint efficiencies. The maximum joint efficient was about 37% compared to strength of base metal. It is better than that of arc brazed joint of DP steel using Cu-Sn filler metal. Fracture position of all brazing conditions was in the fusion zone. Crack initiation occurred at three junction point which was a stress singularity point of upper sheet, lower sheet and the fusion zone. And then crack propagated across the fusion zone. The reason why the fracture occurred at fusion zone was that the hardness of fusion zone was lower than that of base material and heat affected zone. The correlation among maximum load and hardness of fusion zone and EST at fractured position was $R^2=0.9338$. Therefore, this means that hardness and EST can have great impact on maximum load.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 추계학술대회
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• pp.25-25
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• 2018

The Fukushima Daiichi Nuclear Power Plant accident in March 2011 caused severe radioactive contamination in the surrounding environment. Since the accident, much attention has been paid to the biological and genetic consequences of organism inhabiting the contaminated area. The effect of radiation exposure on genetic mutation rates is little known, especially for low doses and in situ conditions. Evaluating DNA mutation by low levels of radiation dose is difficult due to the rare mutation event and lack of sequence information before the accident. In this study, correlations with air dose levels and somatic DNA mutation rates were evaluated using Next Generation Sequencer for the clonal plant, Phyllostachys edulis. This bamboo is known to spread an identical clone throughout Japan, and it has the advantage that we can compare genetic mutation rate among identical clone growing different air dose levels. We collected 94 samples of P. edulis from 14 sites with air dose rates from $0.04{\sim}7.80{\mu}Gy/h$. Their clonal identity was confirmed by analysis using 24 microsatellite markers, and then, sequences among samples were compared by MIG sequence. The sequence data were obtained from 2,718 loci. About ~200,000 bp sequence (80 bp X 2,718 loci) were obtained for each sample, and this corresponds to about 0.01% of the genome sequence of P. edulis. In these sequences, 442 loci showed polymorphism patterns including recent origin mutation, old mutation, and sequence errors. The number of mutations per sample ranged from 0 to 13, and did not correlate with air dose levels. This result indicated that DNA mutations have not accumulated in P. edulis living in the air doses levels less than $10{\mu}Gy/h$. Our study also suggests that mutation rates can be assessed by selecting an appropriate experimental approach and analyzing with next generation sequencer.