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云南白族头面部微机测量研究 总被引:2,自引:0,他引:2
白族是云南省特有少数民族之一,有关白族头面部器官全面系统的测量研究至今尚未见报道。本研究采用本课题组自行研制的头面部摄像-计算机测量系统,对云南大理白族自治州剑川县沙溪乡198名正常白族成人进行了头面部器官全面系统的测量研究,其中成年男性104人,成年女性94人,得出了白族成年男女两性头面部器官40个测量项目的正常值和17个头部指数的资料,并以5个头面部指数对头型、面型和鼻型进行了分类,该研究不仅对人类学、民族学等学科具有重要意义,而且对医学和工业等相关学科也有重要的参考价值。 相似文献
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河南新乡地区儿童头面部测量 总被引:4,自引:3,他引:1
本文对河南省新乡地区汉族儿童(4-13岁)头面部进行了测量,比较和分析了儿童体质发育与年龄增长的关系,据儿童头面部各指数数值大小分型,确定该地区汉族儿童面部的形态为:圆头型、高头型、狭头型、狭面型、狭鼻型。 相似文献
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本项目对1896例腊尔山区6~16岁苗族学生(男919例,女977例)进行了人体测量,测量了10项头面部形态指标,并根据公式计算13项头面部指数值。结果表明,苗族学生头面部各指标均值随年龄增长而增加,同年龄段头面部各指标均值男生一般高于女生,且多数年龄段差异有统计学意义;男性的头长宽的、形态面的、形态上面的、容貌面的、颧额宽的、容貌上面的和容貌上面高的指数以及女性的形态面的、形态上面的、容貌面的、颧下颌宽度的、容貌上面高的指数随年龄增长总体趋势是先增加后递减;男性头面高的以及女性的头长高的、头宽高的和头面宽的指数随年龄增长逐渐增加;男女性之间的头长高的、头宽高的和额顶宽的指数比较显示,多数年龄段差异有统计学意义;苗族学生头型以中头型、高头型、阔头型多见,面型以阔面型、阔上面型为主;相对于其他族群,腊尔山苗族男生面型短而宽,头型偏长,女生面型偏短,头型稍偏长而窄。腊尔山苗族学生头面部特征与融水苗族、土家族等族群较为接近,与哈萨克族、新乡汉族相距较远。 相似文献
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湖南侗族体质人类学初步研究 总被引:19,自引:6,他引:13
对湖南省通道侗族自治县575名侗族成年男(295)女(280)进行了活体测量,根据身高、头面部等测量结果,分析该民族的体质特征。 相似文献
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本文对传统的颅骨测量法与口腔医学上使用的X线头影测量法在测量标志点的选取定位及测量结果的差异方面进行了对比研究。测量标志点重叠对比显示颅骨测量中的大多数标志点在X线片上可以较为准确地定位。方差分析表明两种测量方法测量结果差异不显著(P>0.05)。本文就如何准确地在X线片上确定标志点以及测量数据的放大误差问题进行了讨论并提出了将放大率划分为三个等级计算X线头影片测量值的标准。作者认为采用X线头影测量方法进行人类学研究有着良好的应用前景。 相似文献
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本文对近年来测量的45254例(男19892例,女25362例)中国人的18项头面部测量数据,按地理分区进行统计与主成分分析,发现中国东北、华北人群男性耳较长,两眼外角距离较近、鼻较狭,头、面较宽;华南人群耳较短,眼、鼻较宽,头较狭,面较狭;东北、华北人群女性面较高,面较宽,两眼距离较大,耳较长;华南、西南人群女性面较低,面较狭,两眼距离较近,耳较短。对中国人群和外国人群头面部数据进行主成分分析和聚类分析,发现中国人群男性、女性头面部特征都相对接近于高加索人种的波斯人、北美白人,与尼格罗人种的非裔美国人差距较大,与南亚人差距也较大;中国男性容貌耳长,眼内角间宽、鼻宽、头宽、形态面高值多小于尼格罗人种的4个人群,形态面高值多小于高加索人种的波斯人;中国女性鼻宽、口宽值小于非裔美国人,容貌面高、眼内角间宽、面宽多大于北美白人、伊朗人。中国地理分区人群头面部特征的共性与人群间长期的融合、具有相似的遗传结构有关,环境因素是其存在差异的重要原因。 相似文献
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Charles Menzie Miranda Hope Henning Jerome Cura Kenneth Finkelstein Jack Gentile James Maughan 《人类与生态风险评估》1996,2(2):277-304
Weight‐of‐evidence is the process by which multiple measurement endpoints are related to an assessment endpoint to evaluate whether significant risk of harm is posed to the environment. In this paper, a methodology is offered for reconciling or balancing multiple lines of evidence pertaining to an assessment endpoint. Weight‐of‐evidence is reflected in three characteristics of measurement endpoints: (a) the weight assigned to each measurement endpoint; (b) the magnitude of response observed in the measurement endpoint; and (c) the concurrence among outcomes of multiple measurement endpoints. First, weights are assigned to measurement endpoints based on attributes related to: (a) strength of association between assessment and measurement endpoints; (b) data quality; and (c) study design and execution. Second, the magnitude of response in the measurement endpoint is evaluated with respect to whether the measurement endpoint indicates the presence or absence of harm; as well as the magnitude. Third, concurrence among measurement endpoints is evaluated by plotting the findings of the two preceding steps on a matrix for each measurement endpoint evaluated. The matrix allows easy visual examination of agreements or divergences among measurement endpoints, facilitating interpretation of the collection of measurement endpoints with respect to the assessment endpoint. A qualitative adaptation of the weight‐of‐evidence approach is also presented. 相似文献
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脑血流量测量对于脑血管疾病、脑肿瘤诊断和疗效评估具有重要的临床价值。PET是基于正电子示剂技术无创性、精确测量脑血流量的方法,正日益广泛地应用于临床。按照PET测量脑血流量的方法和使用的正电子示踪剂不同,其测量方法分为平衡法、放射自显影法和动力学方法三种。18O-H2O示踪剂PET测量脑血流量被认为测量脑血流方法的"金标准"。随着PET设备分辨率提高、新的图像重建方法使用和PET与MRI图像融合技术不断成熟,18F-FDG首次通过、采用图像衍生动脉输入函数(imagederived arterial input function,IDAIF)替代动脉抽血样精确测量脑血量方法受到广泛重视,有可能逐步取代高成本的18O-H2O测量脑血流量。PET无创、方便和精确测量脑血流量的方法在临床应使用有助于脑血管性疾病、脑肿瘤和脑退行性病变早期诊断、鉴别诊断和个性化医疗。本文介绍PET脑血流量测量原理、方法和临床应用进展。 相似文献
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A W Smeulders L Dorst 《Analytical and quantitative cytology and histology / the International Academy of Cytology [and] American Society of Cytology》1985,7(4):242-249
Measurement is the instrument of morphometry. Several recurring issues of measurement are reviewed: types of measurement scales and their statistical consequences; types of measurement errors and their relationship to measurement scales; the differences between image resolution, digitization resolution and measurement resolution; and image measurement methods. The importance of formalized measurement protocols is illustrated with an example from daily morphometric practice. 相似文献
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This article presents measurement methods used to determine the human exposure to electromagnetic fields radiated from operating base stations. In Korea, when evaluating the human exposure to electromagnetic fields from operating base stations, the measurement procedure is different between the following cases: in situ measurement and electromagnetic environment measurement. When performing an in situ measurement, compliance with human exposure limits is determined by the spatially averaged field value obtained within the space occupied by humans at one arbitrary position, but when performing an electromagnetic environment measurement, it is determined by the maximum value at the highest field position selected from several places. 相似文献
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Gantzer ML Miller WG 《The Clinical biochemist. Reviews / Australian Association of Clinical Biochemists》2012,33(3):95-100
Clinical laboratory measurement results must be comparable among different measurement procedures, different locations and different times in order to be used appropriately for identifying and managing disease conditions. Harmonisation in the broad sense is the overall process of achieving comparability of results among clinical laboratory measurement procedures that measure the same measurand. The term standardisation is used when comparable results among measurement procedures are based on calibration traceability to SI using a reference measurement procedure of the highest available order. When there is no higher order reference measurement procedure available, and it is unlikely that one can be developed, the term harmonisation refers to any process for achieving comparable results among measurement procedures for an individual measurand.This review explains calibration traceability and focuses on the principles of harmonisation for those measurands for which a reference measurement procedure does not exist. We discuss the value of harmonisation, the importance of commutable reference materials, the barriers to harmonisation that exist today, and conclude with a discussion of a current global effort to improve the state of harmonisation. 相似文献
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Lauer O Neubauer G Röösli M Riederer M Frei P Mohler E Fröhlich J 《Bioelectromagnetics》2012,33(1):75-85
Body-worn radiofrequency electromagnetic field (RF-EMF) personal exposure meters (PEMs) have been increasingly used for exposure assessment in epidemiological research. However, little research on the measurement accuracy of these devices is available. In this article a novel measurement setup and a measurement protocol are presented for characterizing and testing PEMs. The whole setup and procedure is tested using two EME SPY 120 devices. The performance of the PEM was analyzed for absolute measurements in an anechoic chamber. Modulated signals representing the different services as real signals generated by appropriate testers were used. Measurement results were evaluated with respect to a root mean square detector. We found that measurement accuracy depends strongly on the carrier frequency and also on the number of occupied time slots for Time Division Multiple Access (TDMA)-based services. Thus, correction factors can only be derived if the distribution of the network configuration over the measurement time for all measurement points is available. As a result of the simplicity of the measurement setup and the straightforward measurement protocol, the possibility of fast validation leads to a higher accuracy in the characterization and testing of PEMs. 相似文献
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与现代人工肩关节假体设计有关的各项解剖参数测量方法很多,包括标本解剖学测量、X线平片测量、CT测量等。由于测量方法及定义线的不一致,导致较多参数测值差别太大,给肩关节假体设计及手术带来不便。本文就盂肱关节骨性结构解剖参数的测量进行综述,提出测量方法应统一到CT或MRI三维重建测量上来,以满足现代肩关节假体设计解剖与解剖关系重建的核心理念。 相似文献
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Population abundances are rarely, if ever, known. Instead, they are estimated with some amount of uncertainty. The resulting measurement error has its consequences on subsequent analyses that model population dynamics and estimate probabilities about abundances at future points in time. This article addresses some outstanding questions on the consequences of measurement error in one such dynamic model, the random walk with drift model, and proposes some new ways to correct for measurement error. We present a broad and realistic class of measurement error models that allows both heteroskedasticity and possible correlation in the measurement errors, and we provide analytical results about the biases of estimators that ignore the measurement error. Our new estimators include both method of moments estimators and "pseudo"-estimators that proceed from both observed estimates of population abundance and estimates of parameters in the measurement error model. We derive the asymptotic properties of our methods and existing methods, and we compare their finite-sample performance with a simulation experiment. We also examine the practical implications of the methods by using them to analyze two existing population dynamics data sets. 相似文献
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本文简述了林木蒸腾耗水的概念、研究价值和研究进展,从实测法和估测法的角度,综述了林木蒸腾耗水量的主要测算方法,对比了各方法的优缺点、适用性、局限性、应用现状以及适用尺度。本研究认为: 实测法可应用于多种空间尺度耗水量的测定,估测法常应用于大空间尺度蒸散量的测算。实测法是估测法的基础,因此应对实测法的测定结果进行合理的质量控制与评价,为校正估测法的估算结果提供数据基础。不管是同一大空间尺度还是不同空间尺度,实测法和估测法的结合能够提高蒸散量测算结果的准确性。提升复杂下垫面和恶劣气候环境下大空间尺度林木蒸散量的测算精度将成为未来的研究热点与难点。随着科学技术的不断进步,现有的测定装置和测算方法将被改进,精确测定林木蒸腾耗水量的新方法也将随之诞生。 相似文献