• 제목/요약/키워드: contact point

검색결과 1,218건 처리시간 0.213초

자율주행자동차 정면충돌평가방안 마련을 위한 국내 정면충돌사고 심층분석 연구 (An In-depth Analysis of Head-on Collision Accidents for Frontal Crash Tests of Automated Driving Vehicles)

  • 박요한;박원필;김승기
    • 자동차안전학회지
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    • 제15권4호
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    • pp.88-94
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    • 2023
  • The seating postures of passengers in the automated driving vehicle are possible in atypical forms such as rear-facing and lying down. It is necessary to improve devices such as airbags and seat belts to protect occupants from injury in accidents of the automated driving vehicle, and collision safety evaluation tests must be newly developed. The purpose of this study is to define representative types of head-on collision accidents to develop collision standards for autonomous vehicles that take into account changes in driving behavior and occupants' postures. 150 frontal collision cases remained by filtering (accident videos, images, AIS 2+, passenger car, etc…) and random sampling from approximately 320,000 accidents claimed by a major insurance company over the past 5 years. The most frequent accident type is a head-on collision between a vehicle going straight and a vehicle turning left from the opposite side, accounting for 54.7% of all accidents, and most of these accidents occur in permissive left turns. The next most common frontal collision is the center-lane violation by drowsy driving and careless driving, accounting for 21.3% of the total. For the two types above, data such as vehicle speed, contact point/area, and PDOF at the moment of impact are obtained through accident reconstruction using PC-Crash. As a result, two types of autonomous vehicle crash safety test scenarios are proposed: (1) a frontal oblique collision test based on the accident types between a straight vehicle and a left-turning vehicle, and (2) a small overlap collision test based on the head-on accidents of center-lane violation.

The effect of in-situ stress parameters and metamorphism on the geomechanical and mineralogical behavior of tunnel rocks

  • Kadir Karaman
    • Geomechanics and Engineering
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    • 제37권3호
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    • pp.213-222
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    • 2024
  • Determination of jointed rock mass properties plays a significant role in the design and construction of underground structures such as tunneling and mining. Rock mass classification systems such as Rock Mass Rating (RMR), Rock Mass Index (RMi), Rock Mass Quality (Q), and deformation modulus (Em) are determined from the jointed rock masses. However, parameters of jointed rock masses can be affected by the tunnel depth below the surface due to the effect of the in situ stresses. In addition, the geomechanical properties of rocks change due to the effect of metamorphism. Therefore, the main objective of this study is to apply correlation analysis to investigate the relationships between rock mass properties and some parameters related to the depth of the tunnel studied. For this purpose, the field work consisted of determining rock mass parameters in a tunnel alignment (~7.1 km) at varying depths from 21 m to 431 m below ground surface. At the same excavation depths, thirty-seven rock types were also sampled and tested in the laboratory. Correlations were made between vertical stress and depth, horizontal/vertical stress ratio (k) and depth, k and Em, k and RMi, k and point load index (PLI), k and Brazilian tensile strength (BTS), Em and uniaxial compressive strength (UCS), UCS and PLI, UCS and BTS. Relationships were significant (significance level=0.000) at the confidence interval of 95% (r = 0.77-0.88) between the data pairs for the rocks taken from depths greater than 166 m where the ratio of horizontal to vertical stress is between 0.6 and 1.2. The in-situ stress parameters affected rock mass properties as well as metamorphism which affected the geomechanical properties of rock materials by affecting the behavior of minerals and textures within rocks. This study revealed that in-situ stress parameters and metamorphism should be reviewed when tunnel studies are carried out.

Efficacy of plasma treatment for surface cleansing and osseointegration of sandblasted and acid-etched titanium implants

  • Gang-Ho Bae;Won-Tak Cho;Jong-Ho Lee;Jung-Bo Huh
    • The Journal of Advanced Prosthodontics
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    • 제16권3호
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    • pp.189-199
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    • 2024
  • PURPOSE. This study was conducted to evaluate the effects of plasma treatment of sandblasted and acid-etched (SLA) titanium implants on surface cleansing and osseointegration in a beagle model. MATERIALS AND METHODS. For morphological analysis and XPS analysis, scanning electron microscope and x-ray photoelectron spectroscopy were used to analyze the surface topography and chemical compositions of implant before and after plasma treatment. For this animal experiment, twelve SLA titanium implants were divided into two groups: a control group (untreated implants) and a plasma group (implants treated with plasma). Each group was randomly located in the mandibular bone of the beagle dog (n = 6). After 8 weeks, the beagle dogs were sacrificed, and volumetric analysis and histometric analysis were performed within the region of interest. RESULTS. In morphological analysis, plasma treatment did not alter the implant surface topography or cause any physical damage. In XPS analysis, the atomic percentage of carbon at the inspection point before the plasma treatment was 34.09%. After the plasma treatment, it was reduced to 18.74%, indicating a 45% reduction in carbon. In volumetric analysis and histometric analysis, the plasma group exhibited relatively higher mean values for new bone volume (NBV), bone to implant contact (BIC), and inter-thread bone density (ITBD) compared to the control group. However, there was no significant difference between the two groups (P > .05). CONCLUSION. Within the limits of this study, plasma treatment effectively eliminated hydrocarbons without changing the implant surface.

경기ㆍ인천지역 학교급식 조리종사원의 스마트 HACCP 사용의 직무수행도, 직무만족도, 및 직무스트레스에 미치는 요인 분석 (Analysis of Factors Affecting Smart HACCP Utilization: Job Performance, Job Satisfaction, and Job Stress among School Food Service Employees in Gyeonggi-do and Incheon)

  • 박소연;박찬윤
    • 대한영양사협회학술지
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    • 제30권2호
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    • pp.95-111
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    • 2024
  • The Smart Hazard Analysis Critical Control Point (HACCP) management system, which integrates information technology (IT) to automate and analyze big data, has been introduced into school food services. This study investigated the job performance, job satisfaction, and job stress of employees in school food services using Smart HACCP. Data were collected via questionnaires from 350 employees in school food services who utilized Smart HACCP and worked in Gyeonggi-do or Incheon. The questionnaire included general information, workplace characteristics, HACCP education status, job performance, and job satisfaction according to the use of Smart HACCP, and general job stress. The responses showed that 92.3% of the participants had received HACCP education in the workplace, and 66.6% understood the content of the education. Among the HACCP process stages, CCP2 (Food Handling and Cooking) and CCP3 (Cooking Completion and Distribution) were the stages at which all participants were using Smart HACCP. CCP3 had the highest percentage (61.4%) of participants who experienced feeling the maximum reduction in their tasks by using Smart HACCP. The Smart HACCP job performance at CCP1 (Inspection) and Smart HACCP job satisfaction were higher in workplaces with 6~10 employees, compared to those with 10≤ employees (both P<0.05). The Smart HACCP job performances at of CP1 (Refrigeration and Freezer Temperature Management) and CP2 (Cleaning and Disinfection of Food Contact Surfaces) were significantly affected by the work area. General job stress was significantly higher in cooks than in cook practitioners, higher in employees with cook certification than in those without it, and higher in employees with work experience (<1 year), compared to those with 5~10 years or 10~15 years' experience. In conclusion, employees' job performance and satisfaction with Smart HACCP need to be enhanced to improve hygiene in school food service. This requires the effective management of their job stress.

PVT 공법의 공정 변수가 고순도 반절연 SiC 단결정의 저항에 미치는 영향 (The effect of PVT process parameters on the resistance of HPSI-SiC crystal)

  • 나준혁;강민규;이기욱;최예진;박미선;정광희;이규도;김우연;이원재
    • 한국결정성장학회지
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    • 제34권2호
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    • pp.41-47
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    • 2024
  • 본 연구에서는 SiC(Silicon Carbide) 분말의 순도와 결정 성장 후 냉각 속도를 제어하여 PVT(Physical Vapor Transport) 방법으로 성장한 4인치 HPSI(High-Purity Semi-Insulating)-SiC 단결정의 저항 특성을 조사하였다. 순도가 다른 2개의 β-SiC 분말을 사용하였고, 성장 후 냉각 속도를 조절하여 다양한 저항값을 얻었다. 성장된 결정의 투과/흡수 스펙트럼 및 결정 품질은 각각 UV/VIs/NIR 분석과 XRD Rocking curve 분석을 이용하였으며, 비접촉 비저항 분석을 통해 전기적 특성을 조사하여 비저항 특성에 우세한 영향을 미치는 주요 요인을 확인하였다.

한국 문화 산업의 글로벌 생산 네트워크에 관한 연구 (Research on Korean Cultural Industry Based on Global Production Networks Theory )

  • 진자량;줄리안 슈와베;이승철
    • 한국경제지리학회지
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    • 제26권4호
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    • pp.408-420
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    • 2023
  • 문화산업은 일반인에게 가장 밀접한 산업이기 때문에 대중들이 비교적 쉽게 접근할 수 있는 산업이다. 최근 인터넷의 발달로 다양한 국가의 사람들이 긴밀하게 연계되고 있으며, 생산 네트워크도 글로벌 수준에서 상호 연계될 수 있게 되었다. 본 연구는 문화 산업 관련 데이터와 사례 연구를 통해 글로벌 생산 네트워크가 문화 산업을 발전시키는 방식과 메커니즘을 규명하고자 하였다. 본 연구는 한국 영화 및 비디오 산업과 음악 산업의 발전 모델을 네 단계로 구분하여 한국 문화산업의 발전 모델을 구축하였다. 이를 통해 본 연구는 한국 영화 및 비디오 산업과 음악 산업이 아웃소싱 전략을 기반으로 규모가 확장되고 있으며, 대규모 글로벌 협력 기반의 생산 네트워크에 의존하여 대중성과 부가가치가 향상되고 있음을 밝혔다.

병원코디네이터에 대한 지각된 진정성과 공감 및 커뮤니케이션 만족도와 재방문의도와의 관계 (The Relationship between Perceived Authenticity and Empathy and Communication Satisfaction and Revisit Intention for Hospital Coordinators)

  • 윤두윤
    • 한국응용과학기술학회지
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    • 제41권1호
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    • pp.107-118
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    • 2024
  • 본 연구는 의료미용을 위한 상담 시 병원코디네이터와 만나는 접점에서 지각된 진정성이 공감과 커뮤니케이션, 재방문 의도에 미치는 효과를 검증하는데 목적이 있다. 자료수집은 상담을 경험한 고객을 선정하여 설문조사를 실시하였고, 통계분석은 SPSS 21.0을 사용하였다. 연구 결과는 첫째, 병원코디네이터에 대한 지각된 진정성은 공감과 커뮤니케이션 만족도에 긍정적인 영향을 미쳤으며, 공감은 커뮤니케이션 만족도에 정의 영향을 주었다. 둘째 공감과 커뮤니케이션 만족도는 재방문 의도에 정의 영향을 주는 것으로 나타났다. 병원코디네이터의 진정성 있는 상담은 공감을 형성하여 커뮤니케이션 만족도가 높아지고 병원을 다시 방문하는 결과로 이어진다. 따라서 단순히 매출 향상이나 직무에 의해 만들어진 상담이 아니라 고객을 배려한 진정성과 공감을 통한 커뮤니케이션이 이루어진다면 신뢰를 형성할 수 있으며 장기적으로 의료미용 기관의 성과에도 기여할 수 있을것이다.

일학습병행 재직자학위연계 교육과정 참여학생의 학습성과와 대학측 대응 노력 간의 연관성 고찰 (An Examination of the Relationship between Learning Outcomes of Employees Participating in Work-Study Integrated Degree Programs and University Efforts in Response)

  • 최성연
    • 공학교육연구
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    • 제27권1호
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    • pp.3-12
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    • 2024
  • The degree-linked programs for employees, operated by joint training centers in specialized universities that have implemented work-study integrated programs, are educational programs that require an annual government budget of around 80 billion KRW. However, the 70+ universities running these programs face issues such as a decline in academic achievement and an increase in dropout rates among students. In this paper, I conducted multiple regression analysis based on observed and measured information to examine whether the participating students in these programs are achieving an appropriate level of academic performance and to identify the factors that universities need to invest in to achieve that level. To do this, I hypothesized a causal relationship between the university's input factors and students' academic achievement, and used the SPSS program to analyze the statistical data, confirming the validity of the hypothesis. The collected data for the study were obtained through a survey developed using a Likert 4-point scale, which quantified the distribution of grades among students enrolled in IT-related departments offering the degree-linked programs for employees and the emotional contact efforts made by the universities to motivate them for academic success. Particularly, through the results of multiple regression analysis, it was confirmed that these input factors, unlike those for students in general education programs, require more personalized and frequent interactions.

한국(韓國).몽고복식(蒙古服飾)의 상관성(相關性) 연구(硏究)(II) - 고려시대(高麗時代)의 몽고침략기(蒙古侵略期)를 중심(中心)으로 - (A Study On Interrelationship Between Korean And Mongolian Costume Laying Emphasis On The Age Of Mongolia's Invasion Upon Corea)

  • 손경자
    • 복식
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    • 제16권
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    • pp.15-42
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    • 1991
  • A nation's culture isn't consisted by the characteristics of the nation only, but it is greatly affected by the geographical features and natural conditions, and it could be also dominated by the continual effect through mutual contact on economic exchange or social problem and political interests with neighboring countries. It is a well known fact that the contact of culture between Korea and Mongolia established under the special political situation that Corea was invaded by Won. But more basically, the Nomad including Mongolia had influenced upon neighboring countries, therefore, our country was also greatly influenced on consisting of our own culture by them. Moreover. the fact that our language belongs to their language's category(mostly Tweigru and Mongolian language) proves that the origin of our culture was deeply related with Mongolia. Accordingly, we could not limit the cultural relation between Korea and Mongolia within a special era. But especially, since unification of China by Mongolia, Won which appeared as a new great nation had dominated Corea for one hundred years, and the Corea's costume culture had a point of conversion to the mongolian. Therefore, this study expects to comment upon the relations of costume between Corea and Mongolia from a view point of Corea's tribute and royal gifts gifts by Mongolia written on the reference literatures. 1) From the ancient times, between our country and Mongolia there has been a direct or indirect exchange caused by the people's movement or invasion due to very closed neighboring. The relations between Corea and Mongolia have started from the mongolia's requests of tribute for the reason why they helped Corea against the Keoran's invasion, and these relation had continued by King Kongmin's age. 2) Mongolia had plundered a tribute such as dress, cereals, horses, military supplies, soldiers, maiden and little girls etc. from Corea, and therefore, a great confusion occurred on political, economic and social fields. And since King Chungyoul of Corea got married with a Princess of Won, the Corea's position was placed as the Buma nation(nation of son in law) and then high class people of Corea preferred to follow the mongolian costume such as Byunbal (pigtail), Ho dress (mongolian dress), Rouges, Chockturi (a kind of formal cap) and Doturak pigtail ribbon, and some have been applied up to date. On the other hand, the custom of Corea had transmitted to the Mongolian nobility, they called it "Corea Yang(style)". 3) The costume of Corea could be divided into three different periods, the first is the period influenced by Tang and Song's regime, the second is affected by the Won's costume and the third is applying the Myung's regime in the end of Corea. The Mongolian dress was based on the Ho dress form and it has been developed through compounding artistic traditional fields and foreign customs in long history. And Mongolia is composed of various tribes, therefore, they have their own dress for each tribe. Our country and Mongolia had a similar dress form based on Ho dress and both used the Chacksukunggo (jacket with small sleeves and slacks) and Seon(line). And the ornaments of costume such as Chockturi, Doturak pigtail ribbon and Rouges had transmitted and fixed down as a traditional wedding garment, but the Rouges has been used by noble women from the ancient times in our country. Since a member of the Society of Korean Costume has visited Mongolia in August 1990 for the first time, I really recognized the neccesity of more detailed study on the costume relation between Korea and Mongolia, and I will proceed with the study on various fields of costume under cooperation of Institute of Oriental Academy of Mongolia.

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가축분뇨 호기적 퇴.액비화시 발생하는 기체 중의 황 화합물과 암모니아에 대한 오존처리 효과 (Effect of Ozone Application on Sulfur Compounds and Ammonia Exhausted from Aerobic Fertilization System of Livestock Manure)

  • 정광화;황옥화;;이동현;최동윤;유용희
    • 유기물자원화
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    • 제20권4호
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    • pp.118-126
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    • 2012
  • 본 연구를 위한 실험 장치는 하루에 100톤 규모의 돼지분뇨를 퇴비화와 액비화 하는 방식으로 처리하는 시설에 설치되었다. 액비조의 경우 폭기되는 분뇨의 상층부에 흡입부를 설치하고 기체를 빨아들이는 방식으로 실험용 기체시료를 포집하였다. 포집된 시료는 오존이 존재하는 2 종류의 반응조에 유입된 후 오존과 접촉하는 방식으로 처리되었다. 처리효율 분석은 처리시설 유입부 배관에서 채취한 시료와 오존과 반응한 후 배출되는 배관에서 채취한 시료의 성분함량을 비교하여 결정하였다. 퇴비사의 시료는 교반 후 발생하는 기체를 흡입한 후 액비조에서와 같은 방식으로 처리하고 그 효율을 분석하였다. 오존접촉에 의한 반응효과는 암모니아보다는 황 화합물에서 더 크게 나타났다. 암모니아의 경우 오존접촉 방법에 관계없이 10% 내외의 감소효과를 보였다. 반면에 황 화합물은 오존 처리에 의해 상당량 감소하는 결과를 나타냈다. 액비화 시설로부터 발생된 시료의 경우, 유입부에서 50.091, 4.9089, 27.8109, 0.4683 ppvs 의 농도를 보였던 $H_2S$, MM, DMS, DMDS가 반응 후 유출부에서는 각각 1.2317, 0.3839, 14.7279 0.3145 ppvs 수준으로 감소하였다. 같은 조건으로 호기적 퇴비화 과정에서 발생한 시료를 처리한 결과 $H_2S$, MM, DMS, DMDS 농도는 40.6682, 1.3675, 24.2458, 0.8289 ppvs에서 3.013, 불검출, 8.8998, 0.3651 ppvs 수준으로 감소하였다. 액비화 시설에서 발생하는 시료에 또 다른 형태의 오존을 적용한 결과 $H_2S$, MM, DMS, DMDS가 43.397, 1.4559, 3.6021, 0.4061 ppvs 농도 수준에서 각각 불검출, 불검출, 불검출, 0.2185 ppvs 수준으로 감소하였다.