Automatic Defect Detection from SEM Images of Wafers using Component Tree

Sunghyon Kim,Il-seok Oh 대한전자공학회 2017 Journal of semiconductor technology and science Vol.17 No.1

In this paper, we propose a novel defect detection method using component tree representations of scanning electron microscopy (SEM) images. The component tree contains rich information about the topological structure of images such as the stiffness of intensity changes, area, and volume of the lobes. This information can be used effectively in detecting suspicious defect areas. A quasi-linear algorithm is available for constructing the component tree and computing these attributes. In this paper, we modify the original component tree algorithm to be suitable for our defect detection application. First, we exclude pixels that are near the ground level during the initial stage of component tree construction. Next, we detect significant lobes based on multiple attributes and edge information. Our experiments performed with actual SEM wafer images show promising results. For a 1000 × 1000 image, the proposed algorithm performed the whole process in 1.36 seconds.

Automatic Defect Detection from SEM Images of Wafers using Component Tree

Kim, Sunghyon,Oh, Il-seok The Institute of Electronics and Information Engin 2017 Journal of semiconductor technology and science Vol.17 No.1

In this paper, we propose a novel defect detection method using component tree representations of scanning electron microscopy (SEM) images. The component tree contains rich information about the topological structure of images such as the stiffness of intensity changes, area, and volume of the lobes. This information can be used effectively in detecting suspicious defect areas. A quasi-linear algorithm is available for constructing the component tree and computing these attributes. In this paper, we modify the original component tree algorithm to be suitable for our defect detection application. First, we exclude pixels that are near the ground level during the initial stage of component tree construction. Next, we detect significant lobes based on multiple attributes and edge information. Our experiments performed with actual SEM wafer images show promising results. For a $1000{\times}1000$ image, the proposed algorithm performed the whole process in 1.36 seconds.

A Numerical Design and Feasibility Study of Self-Wastage Experiment Using Simulant Material in a Sodium Fast Reactor

Jang, Sunghyon,Takata, Takashi,Yamaguchi, Akira Korean Nuclear Society 2016 Nuclear Engineering and Technology Vol.48 No.2

A sodiume-water reaction takes place when high-pressured water vapor leaks into sodium through a tiny defect on the surface of the heat transfer tube in a steam generator of the sodium-cooled fast reactor. The sodiume-water reaction brings deterioration of the mechanical strength of the heat transfer tube at the initial leakage site. As a result, it damages the crack itself, which may eventually enlarge into a larger opening. This self-enlargement is called "self-wastage phenomenon." In this study, a simulant experiment was proposed to reproduce the self-enlargement of a crack and to evaluate the mechanism of the self-wastage. The damage on the surface of the crack was simulated by making the neutralization reaction with hydrochloric acid solution and sodium hydroxide solution. A numerical investigation was carried out to validate the feasibility of the approach and to determine experimental conditions. From the computation results, it is observed that when 5M HCl is injected into 5M of NaOH with 0.05 m/s inlet velocity, the temperature at the surface near the crack increased over 319.26 K. The computational results show that the self-wastage phenomenon is capable of being reproduced by the simulant experiment.

Brain mapping for long-term recovery of gait after supratentorial stroke : A retrospective cross-sectional study

Kim, Dae Hyun,Kyeong, Sunghyon,Do, Kyung Hee,Lim, Seong Kyu,Cho, Hyong Keun,Jung, Suk,Kim, Hye Won Williams & Wilkins Co 2018 Medicine Vol.97 No.16

<P><B>Abstract</B></P><P>The recovery of independent gait after stroke is a main goal of patients and understanding the relationship between brain lesions and the recovery of gait can help physicians set viable rehabilitation plans. Our study investigated the association between variables of gait parameters and brain lesions.</P><P>Fifty poststroke patients with a mean age of 67.5 ± 1.3 years and an average duration after onset of 62.2 ± 7.9 months were included. Three-dimensional gait analysis and magnetic resonance imaging were conducted for all patients. Twelve quantified gait parameters of temporal-spatial, kinematic, and kinetic data were used. To correlate gait parameters with specific brain lesions, we used a voxel-based lesion symptom mapping analysis. Statistical significance was set to an uncorrected <I>P</I> value <.005 and cluster size >10 voxels.</P><P>Based on the location of a brain lesion, the following results were obtained: The posterior limb of the internal capsule was significantly associated with gait speed and increased knee extension in the stance phase. The hippocampus and frontal lobe were significantly associated with cadence. The proximal corona radiata was significantly associated with stride length and affected the hip maximal extension angle in the stance phase. The paracentral lobule was significantly associated with the affected knee maximal flexion angle in the swing phase and with the affected ankle maximal dorsiflexion angle in the stance phase. The frontal lobe, thalamus, and the lentiform nucleus were associated with kinetic gait parameters.</P><P>Cortical, proximal white matter, and learning-related and motor-related areas are mainly associated with one's walking ability after stroke.</P>

Brain mapping of motor and functional recovery after supratentorial stroke

Choi, Eun Jung,Kyeong, Sunghyon,Jeon, Hyun Min,Kang, Hyunkoo,Kim, Dae Hyun Wolters Kluwer Health | Lippincott Williams Wilkin 2018 NEUROREPORT - Vol.29 No.14

<P>ObjectiveThe present study aimed to identify the brain regions involved in upper and lower limb motor and functional recovery after stroke.MethodsTwenty-five patients (mean age 73.4 years; average duration from stroke onset 50.1 months) were examined. Fractional anisotropy (FA) mapping using diffusion tensor imaging, and clinical measures, including the Fugl-Meyer motor assessment of upper and lower limbs, the Modified Barthel Index (MBI), and Functional Ambulation Category, were used for examinations. Linear regression analyses were carried out with the FA map as a dependent variable, each clinical measure as an independent variable, and patient age as a covariate.ResultsFA in the internal capsule of the posterior limb of the lesioned hemisphere was significantly associated with Fugl-Meyer motor assessment scores for the upper limbs, whereas FAs in the internal capsule of the posterior limb of the lesioned hemisphere, the posterior corpus callosum of the lesioned hemisphere, and the middle cerebellar peduncle of the contralateral hemisphere were associated with Fugl-Meyer motor assessment scores for the lower limb. FA in brain regions with bilateral connection fibers was commonly associated with the score on the Korean version of the MBI and participants' functional ambulation. Furthermore, the FA in the corticospinal tract in the contralesional hemisphere was also associated with the score on the Korean version of the MBI (corrected P<0.05).ConclusionMotor and functional recovery of upper and lower limbs involves different brain regions. This finding is of particular relevance for treatment and recovery in stroke.</P>

Analysis of Steam Generator Tube Rupture Accidents for the Development of Mitigation Strategies

방정진,최기현,정동욱,배성원,Sunghyon Jang,하상준 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.1

We analyzed mitigation strategies for steam generator tube rupture (SGTR) accidents using MARS code under both full-power and low-power and shutdown (LPSD) conditions. In general, there are two approaches to mitigating SGTR accidents: supplementing the reactor coolant inventory using safety injection systems and depressurizing the reactor coolant system (RCS) by cooling it down using the intact steam generator. These mitigation strategies were compared from the viewpoint of break flow from the ruptured steam generator tube, the core integrity, and the possibility of the main steam safety valves opening, which is associated with the potential release of radiation. The “cooldown strategy” is recommended for break flow control, whereas the “RCS make-up strategy” is better for RCS inventory control. Under full power, neither mitigation strategy made a significant difference except for on the break flow while, in LPSD modes, the RCS cooldown strategy resulted in lower break and discharge flows, and thus less radiation release. As a result, using the cooldown strategy for an SGTR under LPSD conditions is recommended. These results can be used as a fundamental guide for mitigation strategies for SGTR accidents according to the operational mode.

Brain network characteristics separating individuals at clinical high risk for psychosis into normality or psychosis

Choi, Soo-Hee,Kyeong, Sunghyon,Cho, Kang Ik K.,Yun, Je-Yeon,Lee, Tae Young,Park, Hye Yoon,Kim, Sung Nyun,Kwon, Jun Soo Elsevier 2017 SCHIZOPHRENIA RESEARCH Vol.190 No.-

<P><B>Abstract</B></P> <P>We aimed to separate individuals at clinical high risk for psychosis (CHR) state into subgroups according to neurobiological characteristics using structural and functional network constructs and examine their clinical characteristics. Structural diffusion tensor imaging and resting-state functional magnetic resonance imaging were performed in 61 healthy controls (HC), 57 individuals at CHR and 29 patients with schizophrenia (SZ). The main outcome was a likelihood ratio calculated from measures of structural and functional network efficiencies, coupling strength of structural and functional networks, and a disease-specific data analysis, resulting in the most probable classification of CHR into HC or SZ. The likelihood ratios revealed that 33 individuals at CHR were likely similar to HC (CHR-HC), and the remaining 24 CHR individuals were similar to SZ (CHR-SZ). The CHR subgroups were comparable to each other in demographic characteristics and clinical symptoms. However, the verbal and executive functions of CHR-HC were similar to those of HC, and those of CHR-SZ similar to SZ. Additionally, CHR-SZ was more responsive to treatment than CHR-HC during the follow-up period. By combining structural and functional data, we could detect the vulnerable population and provide an active intervention in the early phase of the CHR state.</P>

사건 탐지 및 추적을 위해 신문기사에서 자동 추출된 시간정보의 유용성 판단

김평(Pyung Kim),맹성현(Sunghyon Myaeng) 한국정보과학회 2006 정보과학회논문지 : 소프트웨어 및 응용 Vol.33 No.6

시간정보는 정보 추출, 질의응답 시스템, 자동 요약과 같은 자연언어 처리 응용분야에서 중요한 역할을 한다. 사건 탐지 및 추적 분야에서는 기사의 발행일이 기사간 유사도 계산에 많이 사용되고 있지만 그 유용성에는 한계가 있다. 본 연구에서는 사건 탐지 및 추적 시스템의 성능을 향상시키기 위해서, 한국어 신문기사를 대상으로 비교적 간단한 자연언어 처리 기술을 사용해서 시간정보를 추출하는 방법을 개발하였다. 시간표현 어구를 추출하기 위해 품사패턴과 어휘사전이 사용되었고, 추출된 시간표현 어구는 정규화 과정을 통해 특정 시각 또는 기간으로 변환되었다. 실험을 통해 시간표현 추출과정의 정확도를 측정하였고, 기사에서 자동으로 추출된 시간을 사용함으로써 사건 탐지 및 추적 시스템의 성능을 향상시킬 수 있었다. Temporal information plays an important role in natural language processing (NLP) applications such as information extraction, discourse analysis, automatic summarization, and question-answering. In the topic detection and tracking (TDT) area, the temporal information often used is the publication date of a message, which is readily available but limited in its usefulness. We developed a relatively simple NLP method of extracting temporal information from Korean news articles, with the goal of improving performance of TDT tasks. To extract temporal information, we make use of finite state automata and a lexicon containing time-revealing vocabulary. Extracted information is converted into a canonicalized representation of a time point or a time duration. We first evaluated the extraction and canonicalization methods for their accuracy and investigated on the extent to which temporal information extracted as such can help TDT tasks. The experimental results show that time information extracted from text indeed helps improve both precision and recall significantly.

Neural Basis of Ambivalence towards Ideal Self-Image in Schizophrenia

Kim Byung-Hoon,Shin Yu-Bin,Kyeong Sunghyon,Lee Seon-Koo,Kim Jae-Jin 대한신경정신의학회 2020 PSYCHIATRY INVESTIGATION Vol.17 No.5

Objective Little has been explored about a reflection towards self-image in schizophrenia, though it can be related to heterogeneous symptoms of the illness. We identified the neural basis of ambivalence towards ideal self-image in patients with schizophrenia. Methods 20 patients with schizophrenia and 20 healthy controls underwent functional MRI while the self-image reflection tasks of determining whether to agree with sentences describing their actual or ideal self-image that contained one of the adjective pairs with opposite valence. The interaction between the group and ideal ambivalence score was examined, and group differences in functional connectivity related to ambivalence towards ideal self-image were further studied. Results The interaction of group-by-ideal ambivalence score was shown in the dorsal anterior cingulate cortex and dorsolateral prefrontal cortex, where activities were positively correlated with the level of ideal self-image ambivalence in patients, but not in controls. Task-related decrease in functional connectivity was shown between the orbitofrontal cortex and cerebellum in patients. Conclusion The process of reflecting on ambivalent ideal self-image in schizophrenia may be related to aberrant prefrontal activity and connectivity. Abnormality in the prefrontal regions that take part in cognitive conflict monitoring and value judgment may underlie the pathophysiology of increased ambivalence towards ideal self-image.

중국어 정보검색을 위한 확장된 바이그램 분할기법

김운(Yun Jin),강지훈(JiHoon Kang),맹성현(SungHyon Myaeng) 한국정보과학회 2003 한국정보과학회 학술발표논문집 Vol.30 No.2Ⅰ

중국어 문장은 영어와 한국어와 달리 단어에 대한 명확한 한계가 없기 때문에 중국어 정보검색 시스템에서는 중국어 문장에 대한 색인 작업을 각각의 글자를 기본단위로 자르는 방법을 사용하거나 또는 단어의 한계에 관한 정보가 이미 제공된 단어 사전을 이용하여 색인하는 방법을 사용하고 있다. 하지만 이 두 가지 방법은 모두 장단점이 있다. 본 논문에서는 이 두 가지 방법의 장점을 취하고 단점을 보안하는 방법으로 확장한 바이그램 분할기법을 제안하려 한다. 이 방법은 실용성이 있으며, 검색성능 향상을 도모하였다.