Vous avez cherché: each of which represents a distinct crystal s... (Anglais - Perse)

each of which reportedly contains .
هركدووم از محتويات گذارشي .

you can break up the material, for example, into these short, modular units of eight to 12 minutes, each of which represents a coherent concept.
می توانید مثلاً مطالب را به چند قسمت تقسیم کنید، به طوریکه قسمت های هشت تا ۱۲ دقیقه ای داشته باشید، که هر یک به طور منسجم موضوعی را عرضه می کنند.

**ellipse: the set of points for each of which the sum of the distances to two given foci is a constant.
* بیضی: مکان هندسی نقاطی که مجموع فواصل آنها از دو کانون برابر با عددی ثابت باشد.

each degree of longitude is sub-divided into 60 minutes, each of which is divided into 60 seconds.
هر درجه جغرافیایی معمولاً به ۶۰ دقیقه بخش می‌گردد و هر دقیقه نیز به همین ترتیب از ۶۰ ثانیه تشکیل شده‌است.

at the bottom, it is surrounded with 12 windows, each of which is about 1.25 m away from the ookoutside.
در حقیقت بنای اصلی آرامگاه حسین بن علی از آثار معماری آل بویه می‌باشد که بعدها از تعرض مغولان نیز در امان ماند.

its feasible region is a convex polytope, which is a set defined as the intersection of finitely many half spaces, each of which is defined by a linear inequality.
برنامه‌ریزی خطی، یا همان بهینه‌سازی خطی، روشی در ریاضیات است که به پیدا کردن مقدار کمینه یا بیشینه از یک تابع خطی روی یک چندضلعی محدب می‌پردازد.

new versions of the opengl specifications are regularly released by the khronos group, each of which extends the api to support various new features.
نسخه‌های جدید اوپن‌جی‌ال به طور منظم توسط khronos group منتشر می‌شوند که هر یک این رابط برنامه‌نویسی را برای حمایت از قابلیت جدید مختلفی گسترش می‌دهد.

choi and sweetmanoffer two alternative methods to compute the skewness and kurtosis, each of which can save substantial computer memory requirements and cpu time in certain applications.
choi و sweetman دو روش جایگزین برای محاسبه چولگی و کشیدگی پیشنهاد میدهند، که هر کدام میتواند مقدار قابل ملاحظه ای در حافظه مورد نیاز و زمان cpu در کاربردهای معینی، صرفه جویی کند.

on one end, the core of each fiber is etched to form a nano well that will accept 3-μm silica beads, each of which has been coated with several hundred thousand oligonucleotides of a particular sequence
هر کاوشگر قابل اجرا قبل از حمام کردن آرایه در محلولی از یک نوکلئوتید، به طور انتخابی "نقاب برداری" می شود، سپس یک واکنش پوشاننده انجام می شود و مجموعه بعدی کاوشگرها برای آماده شدن برای قرار گرفتن در معرض نوکلئوتید متفاوت، پوشش داده می شون

in this way, the output of a neuron may depend on the input of many different neurons, each of which may have a different degree of influence, depending on the strength and type of synapse with that neuron.
اگرچه تعداد بسیار زیادی سیناپس در مغز انسان وجود دارد، آنها می توانند در دو نوع دسته بندی شوند: الکتریکی و شیمیاییمنبع معمول این جریان، اختلاف پتانسیل تولید شده به صورت موضعی توسط پتانسیل کنش می‌باشد.

in computing, an address space defines a range of discrete addresses, each of which may correspond to a network host, peripheral device, disk sector, a memory cell or other logical or physical entity.
در رایانش، فضای آدرس محدوده‌ای از آدرس‌های گسسته را تعریف می‌کند که هر آدرس می‌تواند به یک میزبان شبکه، دستگاه جانبی، سکتور هارددیسک، خانه‌ای از حافظه یا به یک موجودیت منطقی یا فیزیکی دیگر اشاره کند.

american anthropology is organized into four fields, each of which plays an important role in research on culture: biological anthropology, linguistic anthropology, cultural anthropology, and archaeology.
انسان‌شناسی آمریکایی در چهار رشته (یا زمینه) سازماندهی شده‌است که هرکدام نقشی مهم در پژوهش فرهنگی ایفا می‌کند: انسان‌شناسی بیولوژیک، زبان‌شناسی، انسان‌شناسی فرهنگی و باستان‌شناسی.

for a simple compressible system, the work performed by the system may be written::formula_13where formula_14 is the pressure and formula_15 is a small change in the volume of the system, each of which are system variables.
بسیاری از فیزیک‌دانان آن زمان می‌دانستند که حتی در سیستم‌های با اصطکاک، قانون پایستگی تکانه با تعریف زیر برای تکانه برقرار است::formula_4=== نوشته‌های امروزی ===* goldstein, martin, and inge f., 1993.

=== protection keys ===a protection key mechanism divides physical memory up into blocks of a particular size (e.g., 4 kib), each of which has an associated numerical value called a protection key.
در این روش، حافظه فیزیکی به بلاکهایی با اندازه مشخص (مثلا ۴ کیلوبایتی) تقسیم می‌شود که هر بلاک دارای یک شماره عددی مخصوص می‌باشد که به آن کلید حفاظتی گفته میشود.

other research directions include the development of a covid-19 vaccine and convalescent plasma transfusion.sars-cov-2 has about 66 druggable proteins, each of which has multiple ligand binding sites.
از دیگر اهداف پژوهشی می‌توان به توسعه واکسن کووید-19 و انتقال پلاسمای فرد بهبودیافته اشاره کرد. sars-cov-2 دارای حدود 66 پروتئین دارویی است که هریک از آنها چندین محل اتصال لیگاند دارند.

(xiii) do not follow that of which you have no knowledge. surely the hearing, the sight, the heart - each of these shall be called to account.
از آنچه به آن آگاهی نداری، پیروی مکن، چرا که گوش و چشم و دل، همه مسؤولند.

12 chapter 1 n the human introduction this chapter is the first of four in which we introduce some of the ‘foundations’ of hci. we start with the human, the central character in any discussion of interactive systems. the human, the user, is, after all, the one whom computer systems are designed to assist. the requirements of the user should therefore be our first priority. in this chapter we will look at areas of human psychology coming under the general banner of cognitive psychology. this may seem a far cry from designing and building interactive computer systems, but it is not. in order to design something for someone, we need to understand their capabilities and limitations. we need to know if there are things that they will find difficult or, even, impossible. it will also help us to know what people find easy and how we can help them by encouraging these things. we will look at aspects of cognitive psychology which have a bearing on the use of computer systems: how humans perceive the world around them, how they store and process information and solve problems, and how they physically manipulate objects. we have already said that we will restrict our study to those things that are relevant to hci. one way to structure this discussion is to think of the user in a way that highlights these aspects. in other words, to think of a simplified model of what is actually going on. many models have been proposed and it useful to consider one of the most influential in passing, to understand the context of the discussion that is to follow. in 1983, card, moran and newell [56] described the model human processor, which is a simplified view of the human processing involved in interacting with computer systems. the model comprises three subsystems: the perceptual system, handling sensory stimulus from the outside world, the motor system, which controls actions, and the cognitive system, which provides the processing needed to connect the two. each of these subsystems has its own processor and memory, although obviously the complexity of these varies depending on the complexity of the tasks the subsystem has to perform. the model also includes a number of principles of operation which dictate the behavior of the systems under certain conditions. we will use the analogy of the user as an information processing system, but in our model make the analogy closer to that of a conventional computer system. information comes in, is stored and processed, and information is passed out. we will therefore discuss three components of this system: input–output, memory and processing. in the human, we are dealing with an intelligent information-processing system, and processing therefore includes problem solving, learning, and, consequently, making mistakes. this model is obviously a simplification of the real situation, since memory and processing are required at all levels, as we have seen in the model human processor. however, it is convenient as a way of grasping how information is handled by the human system. the human, unlike the computer, is also influenced by external factors such as the social and organizational environment, and we need to be aware of these influences as well. we will ignore such factors for now and concentrate on the human’s information processing capabilities only. we will return to social and organizational influences in chapter 3 and, in more detail, in chapter 13. 1.1 1.2 input–output channels 13 in this chapter, we will first look at the human’s input–output channels, the senses and responders or effectors. this will involve some low-level processing. secondly, we will consider human memory and how it works. we will then think about how humans perform complex problem solving, how they learn and acquire skills, and why they make mistakes. finally, we will discuss how these things can help us in the design of computer systems. input–output channels a person’s interaction with the outside world occurs through information being received and sent: input and output. in an interaction with a computer the user receives information that is output by the computer, and responds by providing input to the computer – the user’s output becomes the computer’s input and vice versa. consequently the use of the terms input and output may lead to confusion so we shall blur the distinction somewhat and concentrate on the channels involved. this blurring is appropriate since, although a particular channel may have a primary role as input or output in the interaction, it is more than likely that it is also used in the other role. for example, sight may be used primarily in receiving information from the computer, but it can also be used to provide information to the computer, for example by fixating on a particular screen point when using an eyegaze system. input in the human occurs mainly through the senses and output through the motor control of the effectors. there are five major senses: sight, hearing, touch, taste and smell. of these, the first three are the most important to hci. taste and smell do not currently play a significant role in hci, and it is not clear whether they could be exploited at all in general computer systems, although they could have a role to play in more specialized systems (smells to give warning of malfunction, for example) or in augmented reality systems. however, vision, hearing and touch are central. similarly there are a number of effectors, including the limbs, fingers, eyes, head and vocal system. in the interaction with the computer, the fingers play the primary role, through typing or mouse control, with some use of voice, and eye, head and body position. imagine using a personal computer (pc) with a mouse and a keyboard. the application you are using has a graphical interface, with menus, icons and windows. in your interaction with this system you receive information primarily by sight, from what appears on the screen. however, you may also receive information by ear: for example, the computer may ‘beep’ at you if you make a mistake or to draw attention to something, or there may be a voice commentary in a multimedia presentation. touch plays a part too in that you will feel the keys moving (also hearing the ‘click’) or the orientation of the mouse, which provides vital feedback about what you have done. you yourself send information to the computer using your hands, either by hitting keys or moving the mouse. sight and hearing do not play a direct role in sending information in this example, although they may be used to receive 1.2 14 chapter 1 n the human information from a third source (for example, a book, or the words of another person) which is then transmitted to the computer. in this section we will look at the main elements of such an interaction, first considering the role and limitations of the three primary senses and going on to consider motor control. 1.2.1 vision human vision is a highly complex activity with a range of physical and perceptual limitations, yet it is the primary source of information for the average person. we can roughly divide visual perception into two stages: the physical reception of the stimulus from the outside world, and the processing and interpretation of that stimulus. on the one hand the physical properties of the eye and the visual system mean that there are certain things that cannot be seen by the human; on the other the interpretative capabilities of visual processing allow images to be constructed from incomplete information. we need to understand both stages as both influence what can and cannot be perceived visually by a human being, which in turn directly affects the way that we design computer systems. we will begin by looking at the eye as a physical receptor, and then go on to consider the processing involved in basic vision. the human eye vision begins with light. the eye is a mechanism for receiving light and transforming it into electrical energy. light is reflected from objects in the world and their image is focussed upside down on the back of the eye. the receptors in the eye transform it into electrical signals which are passed to the brain. the eye has a number of important components (see figure 1.1) which we will look at in more detail. the cornea and lens at the front of the eye focus the light into a sharp image on the back of the eye, the retina. the retina is light sensitive and contains two types of photoreceptor: rods and cones. rods are highly sensitive to light and therefore allow us to see under a low level of illumination. however, they are unable to resolve fine detail and are subject to light saturation. this is the reason for the temporary blindness we get when moving from a darkened room into sunlight: the rods have been active and are saturated by the sudden light. the cones do not operate either as they are suppressed by the rods. we are therefore temporarily unable to see at all. there are approximately 120 million rods per eye which are mainly situated towards the edges of the retina. rods therefore dominate peripheral vision. cones are the second type of receptor in the eye. they are less sensitive to light than the rods and can therefore tolerate more light. there are three types of cone, each sensitive to a different wavelength of light. this allows color vision. the eye has approximately 6 million cones, mainly concentrated on the fovea, a small area of the retina on which images are fixated. 1.2 input–output channels 15 although the retina is mainly covered with photoreceptors there is one blind spot where the optic nerve enters the eye. the blind spot has no rods or cones, yet our visual system compensates for this so that in normal circumstances we are unaware of it. the retina also has specialized nerve cells called ganglion cells. there are two types: x-cells, which are concentrated in the fovea and are responsible for the early detection of pattern; and y-cells which are more widely distributed in the retina and are responsible for the early detection of movement. the distribution of these cells means that, while we may not be able to detect changes in pattern in peripheral vision, we can perceive movement. visual perception understanding the basic construction of the eye goes some way to explaining the physical mechanisms of vision but visual perception is more than this. the information received by the visual apparatus must be filtered and passed to processing elements which allow us to recognize coherent scenes, disambiguate relative distances and differentiate color. we will consider some of the capabilities and limitations of visual processing later, but first we will look a little more closely at how we perceive size and depth, brightness and color, each of which is crucial to the design of effective visual interfaces. perceiving size and depth imagine you are standing on a hilltop. beside you on the summit you can see rocks, sheep and a small tree. on the hillside is a farmhouse with outbuildings and farm vehicles. someone is on the track, walking toward the summit. below in the valley is a small market town. even in describing such a scene the notions of size and distance predominate. our visual system is easily able to interpret the images which it receives to take account of these things. we can identify similar objects regardless of the fact that they appear to us to be of vastly different sizes. in fact, we can use this information to judge distances. so how does the eye perceive size, depth and relative distances? to understand this we must consider how the image appears on the retina. as we noted in the previous section, reflected light from the object forms an upside-down image on the retina. the size of that image is specified as a visual angle. figure 1.2 illustrates how the visual angle is calculated. if we were to draw a line from the top of the object to a central point on the front of the eye and a second line from the bottom of the object to the same point, the visual angle of the object is the angle between these two lines. visual angle is affected by both the size of the object and its distance from the eye. therefore if two objects are at the same distance, the larger one will have the larger visual angle. similarly, if two objects of the same size are placed at different distances from the eye, the 1.2 input–output channels 17 furthest one will have the smaller visual angle. the visual angle indicates how much of the field of view is taken by the object. the visual angle measurement is given in either degrees or minutes of arc, where 1 degree is equivalent to 60 minutes of arc, and 1 minute of arc to 60 seconds of arc. so how does an object’s visual angle affect our perception of its size? first, if the visual angle of an object is too small we will be unable to perceive it at all. visual acuity is the ability of a person to perceive fine detail. a number of measurements have been established to test visual acuity, most of which are included in standard eye tests. for example, a person with normal vision can detect a single line if it has a visual angle of 0.5 seconds of arc. spaces between lines can be detected at 30 seconds to 1 minute of visual arc. these represent the limits of human visual acuity. assuming that we can perceive the object, does its visual angle affect our perception of its size? given that the visual angle of an object is reduced as it gets further away, we might expect that we would perceive the object as smaller. in fact, our perception of an object’s size remains constant even if its visual angle changes. so a person’s height is perceived as constant even if they move further from you. this is the law of size constancy, and it indicates that our perception of size relies on factors other than the visual angle. one of these factors is our perception of depth. if we return to the hilltop scene there are a number of cues which we can use to determine the relative positions and distances of the objects which we see. if objects overlap, the object which is partially covered is perceived to be in the background, and therefore further away. similarly, the size and height of the object in our field of view provides a cue to its distance. figure 1.2 visual angle 18 chapter 1 n the human a third cue is familiarity: if we expect an object to be of a certain size then we can judge its distance accordingly. this has been exploited for humour in advertising: one advertisement for beer shows a man walking away from a bottle in the foreground. as he walks, he bumps into the bottle, which is in fact a giant one in the background! perceiving brightness a second aspect of visual perception is the perception of brightness. brightness is in fact a subjective reaction to levels of light. it is affected by luminance which is the amount of light emitted by an object. the luminance of an object is dependent on the amount of light falling on the object’s surface and its reflective properties. luminance is a physical characteristic and can be measured using a photometer. contrast is related to luminance: it is a function of the luminance of an object and the luminance of its background. although brightness is a subjective response, it can be described in terms of the amount of luminance that gives a just noticeable difference in brightness. however, the visual system itself also compensates for changes in brightness. in dim lighting, the rods predominate vision. since there are fewer rods on the fovea, objects in low lighting can be seen less easily when fixated upon, and are more visible in peripheral vision. in normal lighting, the cones take over. visual acuity increases with increased luminance. this may be an argument for using high display luminance. however, as luminance increases, flicker also increases. the eye will perceive a light switched on and off rapidly as constantly on. but if the speed of switching is less than 50 hz then the light is perceived to flicker. in high luminance flicker can be perceived at over 50 hz. flicker is also more noticeable in peripheral vision. this means that the larger the display (and consequently the more peripheral vision that it occupies), the more it will appear to flicker. perceiving color a third factor that we need to consider is perception of color. color is usually regarded as being made up of three components: hue, intensity and saturation. hue is determined by the spectral wavelength of the light. blues have short wavelengths, greens medium and reds long. approximately 150 different hues can be discriminated by the average person. intensity is the brightness of the color, and saturation is the amount of whiteness in the color. by varying these two, we can perceive in the region of 7 million different colors. however, the number of colors that can be identified by an individual without training is far fewer (in the region of 10). the eye perceives color because the cones are sensitive to light of different wavelengths. there are three different types of cone, each sensitive to a different color (blue, green and red). color vision is best in the fovea, and worst at the periphery where rods predominate. it should also be noted that only 3–4% of the fovea is occupied by cones which are sensitive to blue light, making blue acuity lower. finally, we should remember that around 8% of males and 1% of females suffer from color blindness, most commonly being unable to discriminate between red and green. 1.2 input–output channels 19 the capabilities and limitations of visual processing in considering the way in which we perceive images we have already encountered some of the capabilities and limitations of the human visual processing system. however, we have concentrated largely on low-level perception. visual processing involves the transformation and interpretation of a complete image, from the light that is thrown onto the retina. as we have already noted, our expectations affect the way an image is perceived. for example, if we know that an object is a particular size, we will perceive it as that size no matter how far it is from us. visual processing compensates for the movement of the image on the retina which occurs as we move around and as the object which we see moves. although the retinal image is moving, the image that we perceive is stable. similarly, color and brightness of objects are perceived as constant, in spite of changes in luminance. this ability to interpret and exploit our expectations can be used to resolve ambiguity. for example, consider the image shown in figure 1.3. what do you perceive? now consider figure 1.4 and figure 1.5. the context in which the object appears 20 chapter 1 n the human allows our expectations to clearly disambiguate the interpretation of the object, as either a b or a 13. however, it can also create optical illusions. for example, consider figure 1.6. which line is longer? most people when presented with this will say that the top line is longer than the bottom. in fact, the two lines are the same length. this may be due to a false application of the law of size constancy: the top line appears like a concave edge, the bottom like a convex edge. the former therefore seems further away than the latter and is therefore scaled to appear larger. a similar illusion is the ponzo illusion (figure 1.7). here the top line appears longer, owing to the distance effect, although both lines are the same length. these illusions demonstrate that our perception of size is not completely reliable. another illusion created by our expectations compensating an image is the proofreading illusion. read the text in figure 1.8 quickly. what does it say? most people reading this rapidly will read it correctly, although closer inspection shows that the word ‘the’ is repeated in the second and third line. these are just a few examples of how the visual system c
مقدمه این فصل اول از چهار فصل است که در آن برخی از "مبانی" hci را معرفی می کنیم. ما با انسان شروع می کنیم، شخصیت اصلی در هر بحث از سیستم های تعاملی. در نهایت، انسان، کاربر، کسی است که سیستم های کامپیوتری برای کمک به او طراحی شده اند. بنابراین نیازهای کاربر باید اولویت اول ما باشد. در این فصل به حوزه‌هایی از روان‌شناسی انسان می‌پردازیم که تحت عنوان کلی روان‌شناسی شناختی قرار دارند. این ممکن است بسیار دور از d به نظر برسد