• Transactions of the Korean Society of Automotive Engineers
• /
• v.18 no.3
• /
• pp.149-155
• /
• 2010

Currently various safety tests are being performed in many countries with growing interest in vehicle safety. However the vehicles which have good safety performance in these tests could not secure the good performance in real car to car accident. So new test protocol using progressive deformable barrier (PDB) was proposed by EEVC in Europe, NHTSA in USA and some vehicle manufacturers, etc. The target of PDB test is to control partner protection in addition to self-protection on the same test. The proposal is to update current ECE R.94 frontal ODB test. So barrier, impact speed, overlap are changed to avoid bottoming-out in the test configuration. In this paper 3 different tests (R.94, EuroNCAP and PDB test) were carried out using current production vehicles with same structure. The results of these tests were compared to understand PDB test. As a result PDB test shows the highest vehicle deceleration and dummy injury because PDB offers a progressive increase in stiffness in depth and height. However vehicle intrusion was affected with rather test velocity than stiffness of deformable barrier. PDB deformation data is used for partner protection assessment using PDB software and it shows that the test vehicle is rather not aggressive.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.18 no.4
• /
• pp.18-30
• /
• 2010

As the automobile industry is developing, the number of deaths and injuries has increased. To reduce the damages from automobile accidents, the government of each country proposes experimental conditions for reproducing the accident and establishes the vehicle safety regulations. Automotive manufacturers are trying to make safer vehicles by satisfying the requirements. The Hybrid III crash test dummy is a standard Anthropomorphic Test Device (ATD) used for measuring the occupant's injuries in a frontal impact test. Since a real crash test using a vehicle is fairly expensive, a computer simulation using the Finite Element Method (F.E.M.) is widely used. Therefore, a detailed and robust F.E. dummy model is needed to acquire more accurate occupant injury data and behavior during the crash test. To achieve this goal, a detailed F.E. model of the Hybrid III 5th percentile female dummy is constructed by using the reverse engineering technique in this research. A modeling process is proposed to construct the F.E. model. The proposed modeling process starts from disassembling the physical dummy. Computer Aided Design (CAD) geometry data is constructed by three-dimensional (3-D) scanning of the disassembled physical dummy model. Based on the geometry data, finite elements of each part are generated. After mesh generation, each part is assembled with other parts using the joints and rigid connection elements. The developed F.E. model of dummy is simulated based on the FMVSS 572 validation regulations. The results of simulation are compared with the results of physical tests.

• Archives of Craniofacial Surgery
• /
• v.21 no.3
• /
• pp.166-170
• /
• 2020

Background: The standard treatment of nasal bone fractures in pediatric patients is closed reduction. Conservative treatment is sometimes performed, but poses a risk of nasal deformity. The aim of this study was to evaluate the outcomes of bone remodeling in pediatric nasal fractures. Methods: Information was extracted from the medical records of patients under 12 years of age who received conservative treatment for a nasal bone fracture and underwent follow-up computed tomography (CT) examinations. The initial fracture and its outcomes over time were graded as excellent, good, or fair according to the malalignment, displacement, or irregularity of the fractured segments. The outcomes of remodeling were evaluated through changes in the grade of the fracture between initial and subsequent CT scans. Results: The review identified 16 patients between March 2015 and December 2019. Their mean age was 6.2 years, and the average follow-up period was 4.9 months. Three of the five patients with a plane I frontal impact showed improved outcomes of remodeling from good to excellent, and the remaining two patients, improved from fair to good. Eight of the 11 patients with plane I lateral impacts showed improved outcomes, from good to excellent, while one patient, improved from fair to good, one patient, improved from fair to excellent, and one patient showed no interval changes. Conclusion: In 15 of these 16 patients with non-severe fractures, the bony contour improved through remodeling, without surgical intervention. Therefore, we suggest that conservative treatment is a feasible option for mild pediatric nasal fractures.

• Dementia and Neurocognitive Disorders
• /
• v.23 no.2
• /
• pp.95-106
• /
• 2024

Background and Purpose: Ventricle enlargement has been implicated in the pathophysiology of Alzheimer's disease (AD). We studied the relationship between ventricular size and cognitive function in patients with AD. We focused on the effect of the initial ventricle size on the rate of cognitive decline in patients with AD. Methods: A retrospective analysis of probable clinical AD participants with more than 2 magnetic resonance imaging images was performed. To measure ventricle size, we used visual rating scales of (1) Cardiovascular Health Study (CHS) score and (2) conventional linear measurement method. Results: Increased clinical dementia rating (CDR) was correlated with a decreased Mini-Mental Status Examination (MMSE) score, and increased medial temporal lobe atrophy (MTLA) and global ventricle size (p<0.001, p<0.001, p=0.021, respectively). There was a significant correlation between the change in cognitive function in the group (70%-100%ile) with a large initial ventricle size (p=0.021 for ∆CDR, p=0.01 for ∆MMSE), while the median ventricle size (30%-70%ile) showed correlation with other brain structural changes (MTLA, frontal atrophy [FA], and white matter) (p=0.036 for initial MTLA, p=0.034 for FA). Conclusions: In this study, the initial ventricle size may be a potential new imaging biomarker for initial cognitive function and clinical progression in AD. We found a relationship between the initial ventricle size and initial AD-related brain structural biomarkers.

• Archives of Craniofacial Surgery
• /
• v.12 no.2
• /
• pp.81-85
• /
• 2011

Purpose: Nasal bone fracture is the most common facial fracture. Although nasal bone fractures are considered to be minor injuries, the incidence of post-traumatic nasal deformity remains high. This study is designed to support management and patient satisfaction by classifying the simple nasal bone fracture, and survey the care method and result, which is compared with other studies. Methods: From May 2008 to April 2010, 334 patients with simple nasal bone fractures visited our hospital. The incidence, cause, types of nasal bone fracture, treatment, and complications are analyzed according to clinical examination, patient's record and radiographic images. Results: The mean age of patients was 30 years old, with 74% of the patients having been male, and 26% were female. The highest incidence of this fracture was between late teens to late twenties. The causes of nasal bone fracture were the following: having slipped or fallen down (39%), violence (16%), sports accident (14%), traffic accident (11%), industrial accident (6%), and others (16%). Patient's radiographic images were analyzed by Stranc and Robertson classification, frontal impact plane I was 38%, plane II was 16%, plane III was 1%, lateral impact plane I was 21%, plane II was 21%, and plane III was 3%. On average, surgical treatment was performed 7.2 days after trauma under general anesthesia. Closed reduction of nasal bone fracture was performed in 99% of patients. In patients with septal injuries, septal management was performed in 76.7% of cases. Aesthetic surgery was done on same time in 24% of patients. There were some complications, such as residual nasal deformity (7.2%), nasal obstruction (0.9%) and hyposmia (0.3%). Conclusion: According to this study, nasal bone fractures occurred commonly in physically active age groups (age 15~29 years), as a result of having slipped or fallen down, at afternoon and at night time. And it could be treated successfully by closed reduction and septoplasty by 7 days after trauma.

• Sleep Medicine and Psychophysiology
• /
• v.20 no.1
• /
• pp.15-21
• /
• 2013

Objectives: Cognitive impairment in restless legs syndrome (RLS) patients can be affected by sleep deprivation, anxiety and depression, which are common in RLS. The objective of this study is to investigate relationship between cognitive impairment and RLS in the non-medicated Korean elderly with controlling for psychiatric conditions. Method: The study sample for this study comprised 25 non-medicated Korean elderly RLS patients and 50 age-, sex-, and education- matched controls. All subjects were evaluated with comprehensive cognitive function assessment tools- including the Korean version of Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet (CERAD-K), severe cognitive impairment rating scale (SCIRS), frontal assessment battery (FAB), and clock drawing test (CLOX). Sleep quality and depression were also assessed with Pittsburgh sleep quality index (PSQI) and geriatric depression scale (GDS). Results: PSQI and GDS score showed no difference between RLS and control group. There was no significant difference between two groups in nearly all the cognitive function except in constructional recognition test, in which subjects with RLS showed lower performance than control group (t=-2.384, p=0.02). Subjects with depression ($GDS{\geq}10$) showed significant cognitive impairment compared to control in verbal fluency, Korean version of Mini Mental Status Examination in the CERAD-K (MMSE-KC), word list memory, trail making test, and frontal assessment battery (FAB). In contrast, no difference was observed between subjects who have low sleep quality (PSQI>5) and control group. Conclusions: At the exclusion of the impact of insomnia and depression, cognitive function was found to be relatively preserved in RLS patients compared to control. Impairment of visual recognition in RLS patients can be explained in terms of dopaminergic dysfunction in RLS.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.18 no.1
• /
• pp.43-52
• /
• 2006

Numerical model tests are done in order to evaluate impact zone of low salinity water on outer region of the developing Saemankeum reservoir. Also saline mixing processes are investigated f3r the inner reservoir with consideration of Mankyoung and Donjin riverine flood discharges when sea water is passing freely through gate. In these analyses 2-d ADCIRC, 3-d TIDED3D and CE-QUAL-ICM models are used. Through models tests, it is found that inner reservoir mixing process caused by inflow of outer sea water occurs gradually. It takes at least one month for complete mixing on Mankyoung part and 6 month on Dongjin part of the reservoir. When Sinsi or Garyeok gates are opened to control inner reservoir level, discharging velocities decrease exponentially from the gates, but show very strong currents of 0.5m/sec to the 10Km region apart. These results imply that hydrodynamic circulation and ecosystem of frontal region of the Saemankeum dike might be affected in amount by gate operations, since low saline inner waters are discharged periodically at ebb tide according to tidal level.

• Journal of Korean Society of Environmental Engineers
• /
• v.37 no.2
• /
• pp.120-125
• /
• 2015

With rapid urbanization, the volume of traffic in urban area has been significantly increased. This in turn led to problem which can be described as Road Traffic Noise. Currently, to alleviate the road traffic noise damage, a demand for installation of soundproofing walls is rising. Among different shapes of soundproof walls being installed, the reflection-type acoustical insulation panel is highly drawing attentions of residents due to the fact that it does not obstruct their field of vision in contrast with the opaque acoustical insulation panel. On the other hand, improving the soundproofing wall of the reflection-type acoustical insulation barrier panel needs to be focused on since it has a possibility to cause a secondary damage by reflected sounds. Therefore, in this research, study has been carried out to improve the forms in order to minimize travelling of reflected sounds through changing the frontal surface shape and geometrical shape of the reflection-type soundproofing panel. A result from comparison between the normal reflection-type soundproofing panel and the improved soundproofing panel, with reduction effects in the noise reflection, showed that the curved type of soundproofing panel has an impact on reducing the noise up to 1.5 dB. Furthermore, from the research conducted, it appears that the increase and decrease in the reflected sounds can be changeable depending on various design factors. Thus, it turns out that the study shows a potential possibility to develop a reduction technology of the reflected sounds pertaining to overall condition on the soundproofing walls.

• Archives of design research
• /
• v.12 no.4
• /
• pp.99-108
• /
• 1999

The interior space in a passenger car is consisted with many partial elements, and the instrument panel is the most important part from all of them, which is designate the total image of the interior design and the space variation, drivability and safety of the interior space. ] The instrument panel of a passenger car in the early age had the concept of a wall between the engine room and the passenger cabin on which the instrument for the driver were fitted. Therefore the central mounting of the instruments was the typical feature regardless of the position of a driver seat. As the automobiles became more functional with many equipments, driver oriented instrument panel with energy absorbing materials had been developed, and that was the beginning of the various instrument panel design of these days. The recent instrument panels of passenger car have the tendency of going back to the central instrument mounting as it was at the past on a few cars for the strict safety regulation, a new production technology and for the enhanced drivability. It can be summarized into a few results as these with the analysis of a few recent instrument panels. -minimizing the total volume for the better frontal visibility. -energy absorbing and passive structures for the strict impact regulations. -revival of central instrument mounting for the convenience and safety through minimizing the difference of the focal length of a driver.

• International Journal of Computer Science & Network Security
• /
• v.22 no.5
• /
• pp.335-341
• /
• 2022

This article is devoted to the study of the process of formation of the digital generation in a distance learning environment. With the introduction of quarantine due to the spread of COVID-19, opponents of digital technologies were forced to turn to relevant resources, while supporters identified new opportunities for the development of didactics and education in general. The irreversibility of the former educational reality became apparent and only the scale of the vision of potential change by interested and disinterested groups differed. Using a comprehensive approach, the authors consider the issues related to the direct and indirect impact of distance learning on children and young people born after the beginning of the XXI century. The article reveals the prerequisites and implications of distance education for the interaction of participants in the educational process. IC technologies during the educational process in the primary grades, in addition to identifying the student's learning deficit, should provide the transmission of non-verbal signals, which are important for children of this age. At the same time in the secondary school IR-technologies are designed to replace frontal learning during the assimilation of knowledge and at the same time not to worsen the quality of the educational process. Formation of students in the HEI takes place in the political science format, constant discussion of problem situations, so the task of introducing IC technology in this process is the accurate transfer of the content of the discussions. Individualization and autonomization of the educational process, its dependence on the results of the choice of educational content, and the use of pedagogical management tools change the philosophy of education for children and youth. The authors conclude that the formation of a digital generation, characterized by an increased level of digital literacy of children and youth, the possession of a certain level of digital capacity requires the use of strategies aimed at optimizing the learning process in a digital educational environment.