Infant life jacket donning trials using children and their parents: Comparison to the Canadian standard

IntroductionCanadian drowning rates for children are high and an increased demand for child flotation devices with novel designs is expected. This experiment was conducted to: 1) record the donning performance of life jackets on children/infants using the methods outlined in the Canadian standard; and 2) to compare the donning performance results to the previously reported results using a soft manikin.MethodFour different child life jackets were procured for evaluation. Adults and their children were recruited from the Halifax region to participate.ResultsFifty-five participants completed at least one donning trial with one of the four life jackets. Findings were in general agreement with the previous manikin study. Manikin testing showed consistent results with human testing for life jackets that are both well designed or poorly designed, but were not consistent for “mediocre” life jackets. Each sub-task added 10 s to the donning process. Incorrect donning was yet again caused by clips and ties that were not colour and/or size coded.Conclusions & recommendationsA manikin may be offered as an alternative for a human in the donning tests. For “mediocre” life jackets that fail the manikin test, a human test can always be used to clarify the situation.     

基于HSV颜色特征和轮廓面积的救生衣检测算法

目前国内外对渡口救生衣检测技术的研究还比较少,因此提出了复杂渡口环境下的一种能够识别救生衣的检测算法。统计救生衣的HSV颜色范围,用先验HSV颜色范围识别出待检测图像中的救生衣可能区域;通过边界跟踪得到图像中所有可能区域的轮廓,计算各个轮廓的面积来排除小面积区域的干扰;最终得到救生衣区域。实验表明,该方法能够比较准确地识别复杂环境下的渡口救生衣。     

Tympanic temperature and heart rate changes in firefighters during treadmill runs performed with different fireproof jackets

Six well-trained firefighters performed six treadmill runs at 70% of the velocity at VO2max (Maximal aerobic velocity MAV = 13.2+/-0.3 km h(-1)). A recovery time of 1 week was allowed between trials. The first session was performed by subjects wearing only shorts (i.e. no fire jacket, J0). A similar protocol was applied subsequently to test the physiological effects associated with the wearing of one of five different fire jackets: one leather (J1) and four textile-type jackets: VTN with membrane (J2), VTN without membrane (J3), Vidal with Kermel HTA (Haute Teneur en Aramide i.e. high density in Aramide) (J4); and Rolland with Kermel HTA (J5). All sessions were performed in a randomized order and in laboratory conditions. Exercise with the fireproof jackets resulted in higher tympanic temperature (Tty), heart rate (HR) and body mass loss (BML) changes compared to J0 (p<0.001). The magnitudes of these changes depended on the type of the jacket. Exercise in the leather jacket (J1) resulted in the highest Tty and HR, which differed significantly from values in all other conditions (p<0.001). The exercise-induced increases in Tty wearing jackets J3 and J5 were also significantly (p < 0.05) higher than those observed with jackets J2 and J4. In conclusion, textile jackets induced less HR and Tty stresses than the leather one. The magnitude of the physiological responses induced by textile jackets were correlated to jacket weight. J2 and J4 jackets were more effective in limiting hyperthermia and any potential detrimental effect on the exercise capacity.     

Tympanic temperature and heart rate changes in firefighters during treadmill runs performed with different fireproof jackets

Six well-trained firefighters performed six treadmill runs at 70% of the velocity at VO_2max (Maximal aerobic velocity MAV = 13.26±0.3 km h^-1). A recovery time of 1 week was allowed between trials. The first session was performed by subjects wearing only shorts (i.e. no fire jacket, J0). A similar protocol was applied subsequently to test the physiological eOEects associated with the wearing of one of five different fire jackets: one leather (J1) and four textile-type jackets: VTN^TM with membrane (J2), VTN^TM without membrane (J3), Vidal^TM with Kermel^® HTA (Haute Teneur en Aramide i.e. high density in Aramide) (J4); and Rolland^TM with Kermel^® HTA (J5). All sessions were performed in a randomized order and in laboratory conditions. Exercise with the fireproof jackets resulted in higher tympanic temperature (Tty), heart rate (HR) and body mass loss (BML) changes compared to J0 (p <0.001). The magnitudes of these changes depended on the type of the jacket. Exercise in the leather jacket (J1) resulted in the highest Tty and HR, which diOEered significantly from values in all other conditions (p<0.001). The exercise-induced increases in Tty wearing jackets J3 and J5 were also significantly (p<0.05) higher than those observed with jackets J2 and J4. In conclusion, textile jackets induced less HR and Tty stresses than the leather one. The magnitude of the physiological responses induced by textile jackets were correlated to jacket weight. J2 and J4 jackets were more effective in limiting hyperthermia and any potential detrimental effect on the exercise capacity.     

在线漏油报警器传感探头设计

在线漏油报警器能够及时报告封闭的冷却装置换热器中发生的漏油现象,这将成为石化企业快速处理漏油换热器,减少经济损失的重要手段。报警器的重要环节之一就是其传感器探头,它的性能好坏直接关系到报警器的可靠性和有效性,在本文中设计的传感探头,主要由超声波激振乳化器和光电检测器两个部分构成。文中叙述了其各部分的原理设计和基本结构。     

Stabilization of an unstable tubular reactor by nonlinear passive output feedback control

The multiple–input multiple–output (MIMO) output feedback (OF) control problem of an exothermic multi-jacket tubular open-loop unstable reactor is addressed. Over its axial length, the reactor has several equally sized cooling jackets. The controller must adjust the jacket temperatures on the basis of per jacket temperature measurements so that the closed-loop system is robustly stable. The problem is solved within a constructive framework, by combining notions and tools from chemical reactor engineering and partial differential equations (PDEs) control systems theory. The result is a MIMO nonlinear OF dynamic control design with (i) a decentralized MIMO passive state feedback (SF) controller implemented with a pointwise observer (PWO), (ii) closed-loop stability conditions in terms of sensor set and control gains, and (iii) efficient late lumping-based on-line implementation. The design is put in perspective with industrial PI and inventory control, and applied to a representative example through numerical simulation with favorable comparison against adaptive controllers.     

A Humanoid Neck System Featuring Low Motion-Noise

This paper presents our recently developed humanoid neck system that can effectively mimic motion of human neck with very low motion noises. The features of low motion noises allows our system to work like a real human neck. Thus the level of acoustic noises from wearable equipments, such as donning respirators or chemical-resistant jackets, induced by human head motion can be simulated and investigated using such a system. Our low motion-noise humanoid head/neck system is based on the spring structure, which can generate 1 degree of freedom (DOF) jaw movement and 3DOF neck movement. To guarantee the low-noise feature, no noise-makers like gear and electro-driven parts are embedded in the head/neck structure. Instead, the motion is driven by seven polyester cables, and the actuators pulling the cables are sealed in a sound insulation box. Furthermore, statics analysis and motion control design of the system have been presented. Experimental results clearly show that the head/neck system can greatly mimic the motion of human head with an A-weighted noise level of 30 dB or below.     

Subjective perceptual methods for comparing backpacks in the field

Subjective perceptual methods have provided useful information in the laboratory about small differences in backpack design when physiological and biomechanical comparisons are ineffective, but have never been used in the field. This study therefore evaluated, in a controlled field trial with 10 male participants, the suitability of quantitative and qualitative subjective perceptual approaches to distinguish between subtle design differences in two backpacks, each loaded to 15 kg. In addition, initial quantitative subjective impressions about the two backpacks during a 15 min simulated ‘in-shop’ trial were compared with post-field trial backpack preference. In the simulated ‘in-shop’ trial the participants ‘tried out’ the backpack in a manner that was very similar to the way that they would normally try out a backpack as if they were considering buying one in an ‘outdoor’ shop. It included donning and doffing the pack several times and walking around the room wearing the backpack. In the controlled field trial, participants carried the two backpacks for approximately 15 min around a 1313 m hilly outdoor track at a self-selected walking pace which elicited a moderate exercise intensity. Seven participants preferred backpack A. Three preferred backpack B. The qualitative approach, which required participants to provide free-format written responses to semi-structured open-ended questions immediately after the field trial, successfully identified specific reasons underlying participants' preferences. The main reasons for preferring backpack A were better balance, weight distribution, stability up and down hill and over obstacles, fewer pressure points on their back and easier strap location and adjustment. The quantitative approach, which involved participants responding to written post-field trial questions on visual analogue or category ratio rating scales, was generally unsuccessful in distinguishing between backpacks. Thus, qualitative subjective perceptual methods appeared to be more useful than quantitative ones in distinguishing between backpacks and in identifying positive and negative design features under controlled field conditions in which participants carry a backpack at a moderately intense self-selected exercise level. However, since the quantitative approach had been successful in distinguishing between backpacks in an earlier similar study, in which participants exercised more intensely by walking uphill on a treadmill at a fixed pace, it is possible that the quantitative subjective perceptual approach may be capable of distinguishing between backpacks in the field if a fixed pace eliciting higher exercise intensity were to be used. Finally, since quantitative responses to questions about the backpacks after a short simulated ‘in-shop‘ trial closely agreed with participants' post-field trial overall backpack preference, it is concluded that initial subjective impressions may be a good guide to backpack preference after limited field usage.     

Infant feeding in an emergency: An oversight in United Kingdom emergency planning

Following the finding of the World Breastfeeding Trends Initiative 2016 assessment that infant feeding is not mentioned in United Kingdom emergency planning guidance, in 2017 information was sought about Local Resilience Forum (LRF) planning. This research covered both guidance for parents on LRF websites and local planning. Considerable variation between areas and a dependence on the existing knowledge and experience of frontline staff was found. In 2020−2022 LRF websites in England and Wales were revisited and information requested about rest centre facilities, procurement of items needed by evacuated parents, provision of skilled support and staff training. Twenty-nine of the 42 LRFs replied, partially or fully, directly or through their local authorities. The variation between areas found in 2017 was confirmed. Areas endeavour to provide for the needs of families but specific training in infant feeding was lacking, although several requested relevant resources or responded that the lack of training would now be reviewed. A short leaflet was produced and circulated to LRFs that had responded to aid training. Using established international guidance to include infant feeding in United Kingdom emergency planning guidance, implemented by national coordinators, would improve consistency between LRFs and better protect infant, child and maternal health and well-being.     

Subjective perceptual methods for comparing backpacks in the field

Subjective perceptual methods have provided useful information in the laboratory about small differences in backpack design when physiological and biomechanical comparisons are ineffective, but have never been used in the field. This study therefore evaluated, in a controlled field trial with 10 male participants, the suitability of quantitative and qualitative subjective perceptual approaches to distinguish between subtle design differences in two backpacks, each loaded to 15 kg. In addition, initial quantitative subjective impressions about the two backpacks during a 15 min simulated 'in-shop' trial were compared with post-field trial backpack preference. In the simulated 'in-shop' trial the participants 'tried out' the backpack in a manner that was very similar to the way that they would normally try out a backpack as if they were considering buying one in an 'outdoor' shop. It included donning and doffing the pack several times and walking around the room wearing the backpack. In the controlled field trial, participants carried the two backpacks for approximately 15 min around a 1313 m hilly outdoor track at a self-selected walking pace which elicited a moderate exercise intensity. Seven participants preferred backpack A. Three preferred backpack B. The qualitative approach, which required participants to provide free-format written responses to semi-structured open-ended questions immediately after the field trial, successfully identified specific reasons underlying participants' preferences. The main reasons for preferring backpack A were better balance, weight distribution, stability up and down hill and over obstacles, fewer pressure points on their back and easier strap location and adjustment. The quantitative approach, which involved participants responding to written post-field trial questions on visual analogue or category ratio rating scales, was generally unsuccessful in distinguishing between backpacks. Thus, qualitative subjective perceptual methods appeared to be more useful than quantitative ones in distinguishing between backpacks and in identifying positive and negative design features under controlled field conditions in which participants carry a backpack at a moderately intense self-selected exercise level. However, since the quantitative approach had been successful in distinguishing between backpacks in an earlier similar study, in which participants exercised more intensely by walking uphill on a treadmill at a fixed pace, it is possible that the quantitative subjective perceptual approach may be capable of distinguishing between backpacks in the field if a fixed pace eliciting higher exercise intensity were to be used. Finally, since quantitative responses to questions about the backpacks after a short simulated 'in-shop' trial closely agreed with participants' post-field trial overall backpack preference, it is concluded that initial subjective impressions may be a good guide to backpack preference after limited field usage.     

Strength limitations to proper child safety seat installation: implications for child safety

A majority of child safety restraints are misused in some manner, often leading to an increased risk of serious injury or death. It is possible that at least some instances of misuse are the result of biomechanical limitations during the installation process. Twenty-seven adult participants were trained and then monitored in three stages of child safety seat installation. All installations were done with an identical restraint system in the rear bench seat of a mocked-up minivan. EMG of 10 muscles, as well as trunk, shoulder, and wrist postures were analyzed. Peak maximum efforts were often required of the trunk extensor, forearm, and anterior shoulder muscles during the installation process. Routing and tightening of the seatbelt, as well as placing and securing the child into the seat were observed to be particularly difficult tasks. Many portions of the child safety seat installation process were found to be very physically demanding; some individuals may not be capable of performing these tasks correctly, thereby putting the child at greater risk in the motor vehicle.     

The effect of load mass and its placement on postural sway

The purpose of this study was to investigate the effects of increasing load on postural sway in two different carrying positions: backpack and waist jacket. Potential differences between males and females were additionally evaluated. 60 young college students participated in this study, and were assigned to backpack and waist jacket groups. The loads in both groups were 12, 21 and 30 kg. Stabilometry was used to assess the amount of postural sway. The medio-lateral and antero-posterior mean sway, mean velocity, medio-lateral and antero-posterior path length and sway area of the centre of pressure position were calculated.In the backpack group all analyzed sway parameters linearly increased with additional load, the differences were significant at p < 0.001. However no significant change of the analyzed parameters was found when the subjects carried additional load in the waist jacket.Our results indicate that postural sway depends on the amount of the load carried in a backpack. Additionally, the position of the load is of significant importance. Carrying weight in a backpack increases postural sway with increasing weight whereas carrying weight in a waist jacket does not influence the amount of postural sway. There are no significant differences in the response to the amount and configuration of the load between male and female subjects.     

Design and evaluation of user’s physical experience in an Ambient Interactive Storybook and full body interaction games

The paper presents the design and evaluation of an original Ambient Interactive Storybook (AIS) for children, including its platform, the background story, and 10 full body interactive games. The evaluation, which focused on the user’s physical experience and elements important to the designer, has been methodologically derived from the Kroflič’s and Laban’s framework Body, Space, Time and Relationship, and additionally supported by sport science measurements. An experiment with 8 participants playing 10 games for 20 min was conducted and recorded to a digital video. Participants’ physical experience was evaluated through the analysis of postures, the quality of the movement, the body parts used in the interaction, the playing area, the direction of movement, direction of gaze, tempo, dynamics and the quantity of motion (QoM). Results of the experiment are discussed in relation and with implications for game design. Conclusions are drawn with the summary of main findings, to better understand the mechanisms and principles involved the design of user’s physical activity in full body interactive games for children. The theoretical work of Laban and Kroflič proved to be useful for interaction and games design in the transition from desktop to full body interactive games.     

Experimental Evaluations of the Twiddler One-Handed Chording Mobile Keyboard

The HandyKey Twiddler? is a one-handed chording mobile keyboard that employs a 3 × 4 button design, similar to that of a standard mobile telephone. We present a longitudinal study of novice users' learning rates on the Twiddler. Ten participants typed for 20 sessions using 2 different text entry methods. Each session was composed of 20 min of typing with multitap and 20 min of one-handed chording on the Twiddler. We found that users initially had a faster average typing rate with multitap; however, after 4 sessions the difference became negligible, and by the 8th session participants typed faster with chording on the Twiddler. Five participants continued our study and achieved an average rate of 47 words per minute (wpm) after approximately 25 hr of practice in varying conditions. One participant achieved an average rate of 67 wpm, equivalent to the typing rate of the 2nd author, who has been a Twiddler user for 10 years.We analyze the effects of learning on various aspects of chording, provide evidence that lack of visual feedback does not hinder expert typing speed, and examine the potential use of multicharacter chords (MCCs) to increase text entry speed. Finally, we explore improving novice user's experience with the Twiddler through the use of a chording tutorial.     

Determining temperature ratings for children's cold weather clothing

This study examined the physical and physiological differences between children and adults that affect body heat generation and losses and then developed a heat loss model for determining the temperature ratings of cold weather clothing designed for use by children of various ages. The thermal insulation values of selected jackets were measured using a heated manikin dressed in two base ensembles, and the temperature ratings were calculated using the model. The results indicated that the type of garments used in the base ensemble had a major effect on jacket ensemble insulation and the predicted comfort temperature. For a given level of insulation, the temperature rating decreased as the wearer's age and activity level increased. This is probably because children have a higher surface area per unit mass ratio than adults, and they lose heat faster. However, this effect is partially offset by their higher metabolic rates.     

Fast quantum codes based on Pauli block jacket matrices

Jacket matrices motivated by the center weight Hadamard matrices have played an important role in signal processing, communications, image compression, cryptography, etc. In this paper, we suggest a design approach for the Pauli block jacket matrix achieved by substituting some Pauli matrices for all elements of common matrices. Since, the well-known Pauli matrices have been widely utilized for quantum information processing, the large-order Pauli block jacket matrix that contains commutative row operations are investigated in detail. After that some special Abelian groups are elegantly generated from any independent rows of the yielded Pauli block jacket matrix. Finally, we show how the Pauli block jacket matrix can simplify the coding theory of quantum error-correction. The quantum codes we provide do not require the dual-containing constraint necessary for the standard quantum error-correction codes, thus allowing us to construct quantum codes of the large codeword length. The proposed codes can be constructed structurally by using the stabilizer formalism of Abelian groups whose generators are selected from the row operations of the Pauli block jacket matrix, and hence have advantages of being fast constructed with the asymptotically good behaviors.     

吉村顺三和他的轻井(泽)山庄设计

本文试图透过轻井山庄的设计,探讨吉村生活的时代,个人成长经历,设计之路选择。以及日后其风格确立,国际影响等,折射出日本现代建筑成功的内在原因,这种思考有助于今日的我们。     

A public procurement combinatorial auction mechanism with quality assignment

This article focuses on mechanism design for quality assignment combinatorial procurement auctions. We model how the participants can maximize social surplus, the difference between gross utility and total cost in electronic procurement, while selecting appropriate quality standards for the procured items. In typical forward combinatorial auctions, the goal is to maximize the sum of all buyers' valuations. In our setting, however, to achieve high buyer utility with low supplier cost, the selected quality levels for the procured items from the suppliers must exceed some predetermined minimum threshold. So the identification of capable suppliers and the corresponding quality assignments are crucial, since buyer utility and supplier cost will be affected by the buyer's quality choice. We develop a novel mechanism to balance the interests of buyers and sellers. Our proposed quality assignment Vickrey-Groves-Clarke (QA-VCG) mechanism is incentive-compatible, provides constraints on partial participation, and is efficient in quasi-linear preferences. In consideration of the perspective of the buyer as a government auctioneer, we also propose a revised mechanism to implement the goal of achieving minimal procurement costs, and appropriate benefits for participating suppliers. We provide a numerical illustration of our QA-VCG mechanism, and an extension that addresses an iterative combinatorial auction mechanism design in our context.     

A study on local cooling of garments with ventilation fans and openings placed at different torso sites

The aim of the study was to examine the various design features of ventilated garments on cooling performance. Five jackets with small ventilation units and closable openings were designed. The ventilation units with a flow rate of 12 l/s were placed at five different torso sites. They were examined on a sweating thermal manikin in four clothing opening conditions in a warm environment (T_a = T_manikin = 34 °C, RH = 60%, V_a = 0.4 m/s). Total torso cooling was increased by 137–251%, and clothing total dynamic evaporative resistance was decreased by 43–69%. Neither the ventilation location nor the opening design had a significant difference on total torso cooling. The ventilation location had a significant difference on localized intra-torso cooling, but not the opening design. When the ventilation units were placed at the local zone where it was ventilated, that zone underwent the highest cooling than other local zones. The study indicated that the ventilation units should be placed at the region where it required the most evaporative cooling, e.g. along the spine area and the lower back. The openings could be adjusted (closed or opened) to make comfortable air pressure for the wearers but without making significant difference on the whole torso cooling under this flow rate.Relevance to industryHeat strain is frequently reported in hot environments, especially for those industries, such as construction, mining and steel. Clothing equipped with the small ventilation units could circulate the ambient air around the body and thus decrease heat strain and improve productivity.     

Shape of progress bar effect on subjective evaluation,duration perception and physiological reaction

Progress indicators act as a status indicator for the visual response process, which in turn has a significant impact on human-computer interaction. We often see ring type and bar type progress indicators in our daily life, but how does one choose the appropriately shaped design? This study uses two experiments to answer the above question, with the aim of maximizing the quality of the user experience. Thirty-six participants were asked to estimate the duration and to evaluate their preferences. The physiological data were collected in real time. The results show that shape affects women's preferences and speed perception for progress indicators. Under the condition of a long waiting time, the waiting experience is better when using the ring type design for all subjects. The quality of the user experience increased when using a progress indicator design that included percentage of task completion. In addition, we provide a reference for the user-friendliness design of progress indicators.