• 한국자동차공학회논문집
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• 제17권2호
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• pp.104-111
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• 2009

In this paper, optimization for frontal crashworthiness is carried out for the weight reduction design of an auto-body member with the advanced high strength steels(AHSS) such as 780TRIP and 780DP. The frontal crashworthiness is evaluated in order to optimize thicknesses for the front rail member of the ULSAB-AVC, Thicknesses of the front rail member with AHSS are optimized by comparison of crushing distance, absorbed energy and the deceleration for the auto-body with the response surface methodology. The results demonstrate that the crashworhiness of the front rail member with the optimum thicknesses of the AHSS is similar to analysis results obtained from the ULSAB-AVC project. The results also show that the weight reduction design is performed by substituting the AHSS for conventional structural steels such as 440E in the auto-body members.

• Journal of Korean Neurosurgical Society
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• 제30권6호
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• pp.777-780
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• 2001

Cholesterol granuloma of frontal bone is a rare disease which usually occurs at the lateral part of the supraorbital ridge. This expanding lesion grows slowly and extends into the orbit and anterior cranial fossa. The most common symptom is proptosis. This granuloma is composed of a granulomatous reaction surrounding cholesterol crystals. Surgical treatment involves aspiration of contents and stripping or curettage of the lining which is highly successful. We experienced a case of cholesterol granuloma of frontal bone with huge intracranial extension, which was cured by surgical removal. The clinical features, radiologic, and pathologic finding were discussed and the pertinent literatures were reviewed.

• 생물정신의학
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• 제25권1호
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• pp.1-8
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• 2018

Insomnia is a common sleep-related symptom which occurs in many populations, however, the neural mechanism underlying insomnia is not yet known. The hyperarousal model explains the neural mechanism of insomnia to some extent, and the frontal cortex dysfunction has been known to be related to primary insomnia. In this review, we discuss studies that applied resting state and/or task-related functional magnetic resonance imaging to demonstrate the deficits/dysfunctions of functional activation and network in primary insomnia. Empirical evidence of the hyperarousal model and proposed relation between the frontal cortex and other brain regions in primary insomnia are examined. Reviewing these studies could provide critical insights regarding the pathophysiology, brain network and cerebral activation in insomnia and the development of novel methodologies for the diagnosis and treatment of insomnia.

• International Journal of Automotive Technology
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• 제5권4호
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• pp.247-255
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• 2004

The majority of real world frontal collisions involves partial overlap (offset) collision, in which only one of the two longitudinal members is used for energy absorption. This leads to dangerous intrusions of the passenger compartment. Excessive intrusion is usually generated on the impacted side causing higher contact injury risk on the occupants compared with full frontal collision. The ideal structure needs to have extendable length when the front-end structure is not capable to absorb crash energy without violating deceleration pulse requirements. A smart structure has been proposed to meet this ideal requirement. The proposed front-end structure consists of two hydraulic cylinders integrated with the front-end longitudinal members of standard vehicles. The work carried out in this paper includes developing and analyzing mathematical models of two different cases representing vehicle-to-vehicle and vehicle-to-barrier in full and offset collisions. By numerical crash simulations, this idea has been evaluated and optimized. It is proven form numerical simulations that the smart structures bring significantly lower intrusions and decelerations. In addition, it is shown that the mathematical models are valid, flexible, and can be used in an effective way to give a quick insight of real life crashes.

• 한국멀티미디어학회논문지
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• 제6권1호
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• pp.167-175
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• 2003

본 논문에서는 전두엽에서의 뇌파 측정시 안전도를 제거할 수 있는 새로운 전극배치법과 제거방법을 제안하였다. 제안한 방식에서는 전두엽에서의 4개의 신호전극과 1개의 접지전극 및 좌측 귓불의 기준전극을 이용하여 뇌파를 측정하였다. 그리고 제안한 전극방식을 통하여 뇌파 측정시 안전도를 제거하기 위하여 ICA를 이용하는 분리방법을 제안하였다. 뇌파 측정실험을 통하여 피험자가 다른 사람의 도움 없이 손쉽게 전극을 사용하여 자신의 뇌파를 측정할 수 있음을 알 수 있었으며 제안한 방법이 뇌파신호로부터 안전도를 제거하는데 유효함을 확인하였다.

• 한국자동차공학회논문집
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• 제10권4호
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• pp.234-241
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• 2002

In this study, the car crash analysis that simulates the crushing behavior of car forestructure during a frontal impact is carried out. The analysis model for front impact of a car consists of the lumped mass and the spring model. The characteristics value of masses and springs is obtained from the static analysis of a target car. The deceleration-time curve obtained from the simulation are compared with NCAP test data from the NHTSA. They show a good agreement with frontal crash test data. The deceleration-time curve of passenger compartment is classified into 3 stages; beginning stage, middle stage, and last stage. And the behavior of masses at each stage is explained. The effect of stiffness variation on deceleration of passenger compartment is resolved. The maximum loaded peak-time of torque box and dash is the main factor to control the passenger compartment's maximum deceleration.

• Journal of Korean Neurosurgical Society
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• 제43권6호
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• pp.304-306
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• 2008

Langerhans' cell histiocytosis (LCH) is a rare immunologic disorder characterized by histiocyte proliferation in multiple organ systems. Eosinophilic granuloma, a benign bone lesion, represents a focal form of LCH. We experienced a case of Langerhans' cell histiocytosis in a patient who presented with intracranial epidural hematoma and cyst on the midline of the frontal skull. A 10-year-old boy presented with a rapidly growing large scalp mass on the midline frontal area after mild head trauma. The scalp mass was painless and immobile. Plain skull x-ray showed a punched-out bone lesion. Computed tomography and magnetic resonance imaging showed a non-enhancing osteolytic lesion presenting with an epidural hematoma and cyst on the midline of the frontal skull. The lesion of the skull was completely resected and the patient's recovery was uneventful. The acute presentation of a solitary eosinophilic granuloma of skull with an epidural hematoma has been described in only five cases in the literature and we report the first case of LCH presenting as an intracranial epidural hematoma on frontal area.

• 인지과학
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• 제16권4호
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• pp.255-270
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• 2005

항목이 연달아 반복되는 경우(집중반복)보다 간격을 두고 반복되는 경우(간격반복) 기억 수행이 더 우수한 현상을 간격효과라 한다. 단서기억과제(재인과제)의 간격효과 및 성공적 부호화와 관련된 신경기전을 밝히기 위해 event-related fMRI연구를 수행하였는데, 부호화단계에서 단어의 반복제시 간격을 조작하고서 fMRI 영상을 구하였다. 그 결과, 재인 수행에서 전형적인 간격효과가 관찰되었고 집중반복조건에 비해 간격반복조건 뿐만 아니라 비반복조건에서 좌반구의 배외측 전두피질(DLFC), 복외측 전두피질(VLFC)의 높은 활성화가 관찰되었다. 이러한 결과는 간격효과 및 이와 관련된 성공적 부호화가 높은 수준의 주의통제와 의미적 처리에 기인한다는 것을 시사한다.

• 한국자기공명학회논문지
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• 제5권1호
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• pp.56-65
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• 2001

Localized in vivo proton magnetic resonance spectroscopy (MRS) was performed to evaluate metabolic alterations in the right and left frontal lobe before and after neuroleptic treatment of schizophrenic patients (n=24) and a group of healthy normal subjects (n=20). Proton metabolic ratios obtained from the 8㎤ yokels in the right and left frontal lobe were compared with the clinical assessment of PANSS for each subject. There was no significant difference in the metabolic ratios between the right and the left frontal lobes in either the schizophrenic group or the control group, indicating no laterality. Compared with those of the normal control group, NAA/Cr and (GABA+Glu)/Cr ratios of the schizophrenic patients showed significantly lower (p=0.023) and higher (p=0.005) value, respectively. The (GABA+Glu)/Cr ratio of the schizophrenic patients was generally decreased after neuroleptic treatment, while the NAA/Cr ratio was not changed. Significant correlation between the (GABA+Glu)/Cr ratio and the clinical symptom scores assessed by PANSS was established. The present study supports the “hypofrontality” hypothesis of schizophrenia on the basis of the altered metabolic ratios before and after neuroleptic treatment.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권5호
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• pp.331-338
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• 2004

The Separation of two amino acids, phenylalanine and tryptophan, was carried out using laboratory simulated moving bed (SMB) chromatography. The SMB process consisted of four zones, with each zone having 2 columns. The triangle theory was used to obtain the operating conditions for the SMB. The mass transfer coefficients of the two amino acids were obtained from the best-fit values by comparing simulated and experimental pulse data. The competitive adsorption isotherms of the two amino acids were obtained by single and binary frontal analyses, taking into consideration the competition between the two components. A competitive Langmuir isotherm, obtained from single-component frontal chromatography, was used in the first run, and the isotherm from binary frontal chromatography in the second, with the flow rate of zone 1 modified to improve the purity. Compared to the first and second runs, the competitive Langmuir isotherm from the binary frontal chromatography Showed good agreement with the experimental results. Also, adjusting the flow rate in zone 1 increased the purity of the products. The purities of the phenylalanine in the raffinate and the tryptophan in the extract were 99.84 and $99.99\%$, respectively.