• 대한안전경영과학회지
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• 제19권1호
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• pp.103-114
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• 2017

The objective of this study is to analyze the needs and determine the requirements of elder drivers for effectively using In-vehicle Information System (IVIS), by reducing cognitive and physical impact on this vulnerable group. The persona method was used to determine the relevant characteristics of older drivers. Task analysis was performed in order to obtain general interaction problems of the personas when using a common function of recent days IVIS. The results were classified in the different usability goals as general requirements, specific needs. This study suggest improvement directions in order to develop an elderly friendly IVIS; in addition, different usability metrics were suggested. In this way, elder drivers would easily interact with new powerful functions supplied by IVIS of modern cars; while improving safety and comfort of an rapidly aging society.

• International Journal of Contents
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• 제14권2호
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• pp.24-29
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• 2018

In this paper, we propose an efficient traffic light detection (TLD) method as an advanced driver assistance system (ADAS) for elderly drivers. Since an increase in traffic accidents is associated with the aging population and an increase in elderly drivers causes a serious social problem, the provision of ADAS for older drivers via TLD is becoming a necessary(Ed: verify word choice: necessary?) public service. Therefore, we propose an economical TLD method that can be implemented with a simple black box (built in camera) and a smartphone in the near future. The system utilizes a color pre-processing method to differentiate between the stop and go signals. A mathematical morphology algorithm is used to further enhance the traffic light detection and a circular Hough transform is utilized to detect the traffic light correctly. From the simulation results of the computer vision and image processing based on a proposed algorithm on Matlab, we found that the proposed TLD method can detect the stop and go signals from the traffic lights not only in daytime, but also at night. In the future, it will be possible to reduce the traffic accident rate by recognizing the traffic signal and informing the elderly of how to drive by voice.

• 한국안전학회지
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• 제24권4호
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• pp.104-110
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• 2009

In this driving simulation study, the impairing effects of various types of electronic devices usage(i. e., destination search by using in-vehicle navigation system, TV watching and dialing cellular phone) during driving on front-to-rear-end collision avoidance were investigated. Percentage of collisions, driving speeds when the drivers collided, and initial reaction time for collision avoidance were analyzed and compared as the dependent measures. The results indicated that (1) any types of electronic devices usage during driving induced more serious collision-related impairment than control condition where no additional task was required, and (2) in general, destination search task appeared to impair drivers collision avoidance performance more than the other task requirements in terms of percentage of collisions and initial reaction time for collision avoidance, but TV watching induced most serious collision impact. These results suggested that any types of electronic device usage could distract drivers attention from the primary task of driving, and be resulted in serious outcome in potentially risky situation of front-to-rear-end collision. In particular, mandatory use of eye-hand coordination and receiving feedback seemed to one of essential factor leading the drivers visual attentional distraction.

• 대한교통학회:학술대회논문집
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• 대한교통학회 2000년도 제37회 학술발표회논문집
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• pp.25-47
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• 2000

In route guidance systems fastest-path routing has typically been adopted because of its simplicity. However, empirical studies on route choice behavior have shown that drivers use numerous criteria in choosing a route. The objective of this study is to develop computationally efficient algorithms for identifying a manageable subset of the nondominated (i.e. Pareto optimal) paths for real-time vehicle routing which reflect the drivers' preferences and route choice behaviors. We propose two pruning algorithms that reduce the search area based on a context-dependent linear utility function and thus reduce the computation time. The basic notion of the proposed approach is that ⅰ) enumerating all nondominated paths is computationally too expensive, ⅱ) obtaining a stable mathematical representation of the drivers' utility function is theoretically difficult and impractical, and ⅲ) obtaining optimal path given a nonlinear utility function is a NP-hard problem. Consequently, a heuristic two-stage strategy which identifies multiple routes and then select the near-optimal path may be effective and practical. As the first stage, we utilize the relaxation based pruning technique based on an entropy model to recognize and discard most of the nondominated paths that do not reflect the drivers' preference and/or the context-dependency of the preference. In addition, to make sure that paths identified are dissimilar in terms of links used, the number of shared links between routes is limited. We test the proposed algorithms in a large real-life traffic network and show that the algorithms reduce CPU time significantly compared with conventional multi-criteria shortest path algorithms while the attributes of the routes identified reflect drivers' preferences and generic route choice behaviors well.

• 한국산업보건학회지
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• 제31권1호
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• pp.31-37
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• 2021

Objectives: The purpose of this study was to evaluate the level of workplace violence experienced by taxi drivers and identify the affected factors. Methods: Two hundred twelve taxi drivers were investigated for general characteristics and workplace violence was evaluated using K_WVSⓇ13. The data was collected from July to October 2020 through questionnaires. It was analyzed using t-test and ANOVA with SPSS WIN23.0. Results: Most of the taxi drivers were elderly and suffered from long hours of labor and low wages. After evaluating four sub-factors of workplace violence, 'psychological and sexual violence from customers', 'psychological and sexual violence from customers, supervisors, and coworkers' and 'physical assault from customers/supervisors/coworkers' were judged as risks. For 'psychological and sexual violence from customers, supervisors, and coworkers', the mean score by age was significantly higher for workers in their 70s or older and those with 30 years of experience compared to other age groups. In the case of 'psychological and sexual violence from customers', sales taxis were significantly higher than private taxis. Conclusions: It is necessary to develop a workplace violence prevention program suitable for the characteristics of taxi drivers in order to manage their physical and mental health. When establishing such a program, business type, age, and experience must be considered.

• 대한치과보철학회지
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• 제52권1호
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• pp.34-41
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• 2014

연구 목적: 임플란트의 종류가 다양해짐에 따라 임플란트 드라이버의 호환성에 대한 연구가 필요하여 임플란트 제품별 드라이버의 형태를 분류하고 직경을 측정하여 비교 분석하였다. 연구 재료 및 방법: 단국대학교 부속치과병원에서 사용 중인 12개회사[Nobel Biocare (Nobel), Institute Straumann (Straumann), Zimmer Dental (TSV), Shinhung (Luna), Astra Tech Dental (Astra), Dentium (Dentium), Osstem Implant (Osstem), DIO Implant (DIO), BIOMET 3i (3i), NeoBiotech (Neo), Megagen Implant (Megagen), SNUCONE (SNUCONE)] 임플란트 제품 드라이버를 연구대상으로 하였으며 임플란트 드라이버의 형태를 분류하고 이 중 호환이 가능한 Hexagon과 torx에 해당하는 드라이버들의 유효길이, 유효길이별 상단, 중단, 하단의 직경을 각각 10개씩 측정하였다. 각 직경의 측정값을 호환성 분석공식에 대입하여 호환성을 산출하였다. 결과: 분석결과, 유효길이 상단에서는 Neo, 3i, Megagen, DIO, SNUCONE, Luna들은 같은 직경(1.20 mm)을 가졌으며 Osstem (1.17 mm)은 호환 가능한 범위에 있었다. Dentium, Astra는 같은 직경(1.25 mm)을 가지며 TSV (1.23 mm) 가 이들과 호환 가능하였다. 유효길이 중단에서는 Dentium과 Astra가 같은 직경(1.35 mm)을 가졌고 3i, DIO, Osstem, TSV도 1.25 mm의 동일한 직경을 가졌다. Neo와 Megagen은 가장 작은 직경(1.22 mm)로 나머지와 호환되었다. 유효길이 하단에서는 일부 드라이버에 호환성이 확인되었으나 대부분 나사의 연결부 깊이가 2 mm 이내인 점을 감안하면 유효하지 않은 결과로 판단되었다. Nobel은 Straumann에 사용할 수 있는 것으로 나타났으며 대부분의 hexagon driver를 trox에 사용할 수 있었다. 결론: 임플란트 드라이버의 각 부위별 직경을 측정한 결과 임플란트 제품간의 호환성이 존재한다는 것을 알 수 있었다. 그러나 호환성이 있는 드라이버의 반복적인 사용이 임플란트 나사와 드라이버에 미치는 영향에 대한 연구가 아직 부족하므로 응급상황 시에만 제한적으로 사용할 것을 권장하며 이에 대한 추가적인 연구가 필요할 것으로 사료된다.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2008년도 추계학술대회 및 정기총회
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• pp.218-233
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• 2008

This study reveals how corporate CRM activities can influence organizational performance by integrating CRM process with customer equity drivers, which have been regarded as independent research areas. The results show that the customer equity drivers including value, brand, and relationship equity mediate between CRM processes and organizational performance. In more detail, customer acquisition, retention, and expansion have positive relationships with brand, relationship, and value equity, respectively. Moreover, even though all customer equity drivers influence organizational performance positively, our analysis suggests that relationship equity has the strongest effect on it.

• JSTS:Journal of Semiconductor Technology and Science
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• 제2권1호
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• pp.82-86
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• 2002

It is demonstrated that the conventional current-pulse laser drivers are not adequate in driving VCSELs operating at multi-Gb/s speeds. Simulation results, including the bonding parasitics, show that high-performance VCSELs are more efficiently driven using voltage-pulse mode of operation. The optical output power is almost doubled in the voltage-mode of operation, while the total electrical power consumption of the transmitter decreases by 20%.

• 융합신호처리학회 학술대회논문집
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• 한국신호처리시스템학회 2003년도 하계학술대회 논문집
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• pp.161-164
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• 2003

This research presents the parallel control scheme of PID servo-driver for shaping of the curved glass. The designed system consists of a PC, main controller and 11 servo-drivers. Each elements are connected by using RS-232C and 8-bit bus communication. In order to guarantee the stability and the control performance, we use the LM629, a precision PID motion controller, and LMD18200, a H-bridge on the servo-drivers. PC calculates position values of 11 DC motors by using the pre-determined curvature value and offers the user interface environment operator.

• 한국자동차공학회논문집
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• 제17권2호
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• pp.90-97
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• 2009

One of the most important factors that affect a person's risk of injury in a motor vehicle crash is the age of the person. This study investigates the characteristics of crash injuries among young, middle-aged and older drivers and occupants. Based on the comprehensive claim data from automobile insurance from 2000 to 2007, this study examines in great detail the drivers and occupants injury body regions and severity by age in car-to-car frontal crashes. It has been shown that elderly drivers and occupants suffer more injuries at a chest region compared to the middle-aged group. This research calls attention to the need for design to make vehicles more protective for older drivers in car-to car frontal crashes.