• 열처리공학회지
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• 제31권1호
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• pp.12-17
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• 2018

We investigated the corrosion behavior of commercially pure cold working processed (CP)-Ti with coarse-grained (CG) microstructure heat-treated at $400^{\circ}C$ and $600^{\circ}C$, respectively. It is observed that corrosion resistance of as-received CP-Ti heat-treated at $400^{\circ}C$, at which recrystallization proceeds, is largely improved. Interestingly, the mechanical property of CP-Ti sample at $400^{\circ}C$ was scarcely deteriorated. It is attributed to the decrease of the defects such as strain variance and dislocation density. On the other hand, the annealing treatment at $600^{\circ}C$ of CP-Ti plate causes to grain growth with the noticeable reduction of mechanical property. Hence, it is considered that defect density such as strain and dislocation density is important microstructural parameter for the improvement of corrosion resistance. The introduction of proper annealing treatment can help to improve corrosion resistance without scarifying mechanical property of CP-Ti.

• 한국정보처리학회논문지
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• 제7권3호
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• pp.992-999
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• 2000

Textile dimension inspection is one of the basic issues in the textile dyeing and finishing industry. And also, it a plays an important role in the quality control of total fabric products. In this paper, we implement a real-time textile dimension inspection system which detects various real defects, defects positions of textile and the density of textiles. The proposed method consists of textile density measurement algorithms with zone-occurrence features from subband image which detect various types of real defects. The performance of the proposed method is tested with a number of real textile samples with 10 types of defects and three basic structures of textile. By the dimension inspection of textile at continuous stages in the fabrication process, it is possible to measure the density of textile up to 150m/min and to detect the defect of textile at real time within $\pm$1% error percentages. And also it can be monitored the condition of textile throughout at all the significant working process and can be improved textile quality.

• Progress in Superconductivity
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• 제14권1호
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• pp.34-38
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• 2012

The effect of graphene inclusion in the ex-situ $MgB_2$ was analyzed with the help of resistivity behavior and critical current density studies. Amount of graphene was systematically varied from 0% for pristine sample to 3% by the weight of $MgB_2$. Graphene that is considered as a good source of carbon was found to be intact without any significant carbon doping in $MgB_2$ structure as reveled by XRD measurements. There was no signature of graphene inclusion as far as the superconducting transition is concerned which remained same at 39 K for all the samples. The transition width being sensitive to defect doping remained more or less about 2 K for all the samples showing no variation due to doping. Although there was no change in the superconducting transition or transition width, the graphene doped sample showed noticeable decrease in the overall resistivity behavior with respect to decrease in temperature. The graphene inclusion acted as effective pinning centers which have enhanced the upper critical field of these samples.

• 한국레이저가공학회지
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• 제14권4호
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• pp.14-20
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• 2011

The advantage of using lasers for through silicon via (TSV) drilling is that they allow higher flexibility during manufacturing because vacuums, lithography, and masks are not required; furthermore, the lasers can be applied to metal and dielectric layers other than silicon. However, conventional nanosecond lasers have disadvantages including that they can cause heat affection around the target area. In contrast, the use of a picosecond laser enables the precise generation of TSVs with a smaller heat affected zone. In this study, a comparison of the thermal and crystallographic defect around laser-drilled holes when using a picosecond laser beam with varing a fluence and repetition rate was conducted. Notably, the higher fluence and repetition rate picosecond laser process increased the experimentally recast layer, surface debris, and dislocation around the hole better than the high fluence and repetition rate. These findings suggest that even the picosecond laser has a heat accumulation effect under high fluence and short pulse interval conditions. To eliminate these defects under the high speed process, the CDE (chemical downstream etching) process was employed and it can prove the possibility to applicate to the TSV industry.

• 한국레이저가공학회지
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• 제11권2호
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• pp.8-14
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• 2008

Sintered specimen which used for a blade of diamond tool was manufactured in order to verify $CO_2$ laser weldability depend on sintered temperature. Five kind of specimen were prepared and the range of temperature is from $600^{\circ}C$ to $1000^{\circ}C$ at intervals of $100^{\circ}C$. As a result of the sintered density test, the porosity rate appeared in the range of $2.1%{\sim}21.4%$. After welding, the most segments had exceeds the minimum fracture stress (600MPa, The Standard Safety of Europe) at the welding strength test except on the sintered at $600^{\circ}C$. In case of the sintered at $700^{\circ}C$, even satisfied the safety allowable stress but cannot get the good quality for bead appearance because of humping defect. In the conclusion, we could know that it showed not only relatively soundness bead but also enough welding strength when the sintered blade of diamond tool is included less than 4% of porosity rate.

• Journal of Chest Surgery
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• 제37권12호
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• pp.999-1002
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• 2004

흉부관통상 환자에서 심장손상이 의심될 때 신속한 이송, 조기 진단 및 체계적인 수술적 치료는 좋은 결과를 얻을 수 있다. 생명을 위협하는 응급상황에서 심장손상의 정도를 진단하는 것은 어려울 수도 있다. 13세 남아가 칼에 의한 흉부 관통상을 입고 흉관으로부터 과도한 출혈이 있어 본원 흉부 외과로 전원되었다. 단순 흉부촬영에서 좌측페야에 균일한 음영 증가가 관찰되었다. 그는 의식이 혼미했으며 생체의 징후는 불안정하여 신속히 수술실로 옮겼다. 소생술 후 정중 흉골절개술을 통해 좌심실 열상을 봉합하였다. 수술 중 시행한 경식도 심초음파에서 심실중격결손에 의한 단락이 발견되었고 좌심실절개하에 데크론 첨포(Dacron patch)를 이용하여 정복하였다. 수술 후 경과는 좋았으며 심실중 격결손을 통한 작은 단락이 있었으나 추적 관찰하기로 하고 퇴원하였다.

• 한국레이저가공학회지
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• 제13권3호
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• pp.1-6
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• 2010

The in-process monitoring of $CO_2$ welding of Zn-coated steel plates has been studied and compared with that of conventional thin plates. Relationships between weld defects and plasma emission signals were evaluated in laser lap joint of thick Zn-coated steel. According to the study, weld defects were found to increase with Zn content. As a result, measured plasma emission signals also decreased. In case of plate with $15{\mu}m$-thick Zn-coated layer, defects caused by evaporation of Zn could, therfore, controled by gap of 0.1mm, resulting in a stable emission signals. However, the amplitude of signals fluctuated very widely. Variation of amplitude sould be limited in 3-8V by FFT smoothing.

• 대한산업공학회지
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• 제40권3호
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• pp.257-266
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• 2014

The semiconductor manufacturing industry is managed by a number of parameters from the FAB which is the initial step of production to package test which is the final step of production. Various methods for prediction for the quality and yield are required to reduce the production costs caused by a complicated manufacturing process. In order to increase the accuracy of quality prediction, we have to extract the significant features from the large amount of data. In this study, we propose the method for extracting feature from the cell level data of probe test process using OPTICS which is one of the density-based clustering to improve the prediction accuracy of the quality of the assembled chips that will be placed in a package test. Two features extracted by using OPTICS are used as input variables of quality prediction model because of having position information of the cell defect. The package test progress for chips classified to the correct quality grade by performing the improved prediction method is expected to bring the effect of reducing production costs.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 제5회 영호남 학술대회 논문집
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• pp.12-14
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• 2003

As the integrated circuit device shrinks to the smaller dimension, the chemical mechanical polishing (CMP). process was required for the global planarization of inter-metal dielectric (IMD) layer with free-defect. However, as the IMD layer gets thinner, micro-scratches are becoming as major defects. Micro-scratches are generated by agglomerated slurry, solidified and attached slurry in pipe line of slurry supply system. It is well known that the presence of hard and larger size particles in the CMP slurries increases the defect density and surface roughness of the polished wafers. In this paper, we have studied. aging effect the of CMP slurry as a function of particle size. We prepared and compared the self-developed silica slurry by adding of abrasives before and after annealing. As our preliminary experiment results, we could be obtained the relatively stable slurry characteristics comparable to original silica slurry in the slurry aging effect.

• 한국주조공학회지
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• 제31권4호
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• pp.198-204
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• 2011

The present study was aimed to investigate the dependence of fatigue property on microporosity variation of low-pressure die-cast (LPDC) A356 alloy. The fatigue property of A356 alloy was evaluated through high cycle fatigue test, and the microporosity-terms used were the fractographic porosity measured from SEM observation on fractured surface and the volumetric porosity obtained through the density measurement using Archimedes's principle. The number of cycles to failure of A356 alloys depends obviously upon the variation of fractographic porosity, and can describe in terms of the defect susceptibility which depends on the microporosity variation at a given value of stress amplitude. The modified Basquin's equation was suggested through the combination of microporosity variation and static maximum tensile stress to fatigue strength coefficient. Using modified Basquin's equation, it could suggest that the maximum values of fatigue strength coefficient and exponent achievable in defect-free condition of A356 alloy are 265 MPa, -0.07, respectively.