• Title/Summary/Keyword: two-stage concrete

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Epistemological Obstacles in the Learning of Area in Plane Figures (평면도형의 넓이 학습에서 나타나는 인식론적 장애)

  • Park, Eun-Yul;Paik, Suck-Yoon
    • Journal of Educational Research in Mathematics
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    • v.20 no.3
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    • pp.305-322
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    • 2010
  • The epistemological obstacles in the area learning of plane figure can be categorized into two types that is closely related to an attribute of measurement and is strongly connected with unit square. First, reasons for the obstacle related to an attribute of measurement are that 'area' is in conflict. with 'length' and the definition of 'plane figure' is not accordance with that of 'measurement'. Second, the causes of epistemological obstacles related to unit square are that unit square is not a basic unit to students and students have little understanding of the conception of the two dimensions. Thus, To overcome the obstacle related to an attribute of measurement, students must be able to distinguish between 'area' and 'length' through a variety of measurement activities. And, the definition of area needs to be redefined with the conception of measurement. Also, the textbook should make it possible to help students to induce the formula with the conception of 'array' and facilitate the application of formula in an integrated way. Meanwhile, To overcome obstacles related to unit square, authentic subject matter of real life and the various shapes of area need to be introduced in order for students to practice sufficient activities of each measure stage. Furthermore, teachers should seek for the pedagogical ways such as concrete manipulable activities to help them to grasp the continuous feature of the conception of area. Finally, it must be study on epistemological obstacles for good understanding. As present the cause and the teaching implication of epistemological obstacles through the research of epistemological obstacles, it must be solved.

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Corrosion Monitoring of Reinforcing Bars in Cement Mortar Exposed to Seawater Immersion-and-dry Cycles (해수침지-건조 환경에 노출된 모르타르속 철근의 부식속도 평가)

  • Kim, Je-kyoung;Kee, Seong-Hoon;Yee, Jurng-Jae
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.4
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    • pp.10-18
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    • 2018
  • The primary purposes of this study are to understand a fundamental aspect of current uniformity around a reinforcing bar (rebar) in cement mortar, and to develop an accurate monitoring method in a wet-dry cycling process with the alternative current (AC) impedance method. Three cement mortar specimens with two embedded rebars were prepared in the laboratory. As a main variable, the distance between two rebars was designed to be 10, 20 and 30 mm with the same thickness of 20 mm. To simulate the corrosion of rebars in concrete structures in a marine environment, three cement mortar specimens were exposed to 15 wet-drying cycles (24-hour-immersion in seawater and 48-hour-drying in a room temperature) in the laboratory. It was observed that the potential level shifted to a noble value during corrosion potential monitoring, which is attributed to acceleration of dissolved oxygen diffusion at the drying process. AC impedance was measured in a frequency range from 100 kHz to 1 mHz on a wet-drying process. A theoretical model was proposed to explain the interface condition between the rebars and cement mortar by using the equivalent circuit consisting of a solution resistance, a charge transfer resistance and a CPE (constant phase element). It was observed that the diffusion impedance appeared in a low frequency range as corrosion of rebars progresses. At the drying stage of the wet-drying cycles, the currents line for monitoring tended to be non-uniform at the interface of rebar/mortar, being phase shift, ${\theta}$, close to $-45^{\circ}$.

Theory of moral leadership in the Great Learning (『대학(大學)』의 수신적(修身的) 지도자론(指導者論))

  • Seo, Eun-Sook
    • (The)Study of the Eastern Classic
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    • no.34
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    • pp.7-38
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    • 2009
  • This paper attempts to explore the theory of moral leadership in the Great Learning. There are two fundamental contents in the elements of moral leadership's human nature in the Great learning. These are meaning of general principle(綱領指趣) - studying, self cultivation and social authority from rectifying name, and category of concrete learning(學問綱目) - the scheme of manifesting original nature (明德之方) and the scheme of loving the people(親民之方). In this, there are two principles. One is the principle of stage. In the theory of moral leadership of the Great learning, there are stages from self-cultivation to making the world tranquil. The other is the principle of stop at the highest good in manifesting nature and loving the people. In the meaning of general principle, moral leader must have good nature that he or she preforms his or her original nature and accomplishes self-cultivation. For this he or she must learn and study, and endeavors self-polishing. In the category of concrete learning, at first, in the scheme of manifesting original nature, there are investigation things-extending knowledge and making the will sincere-rectifying the mind as the pre conditions of the self-cultivation, and moral leader must carry out harmonization peoples and accomplishing public morals as the result of self-cultivation. The harmonization people means that everyone has equal position and lives with each other in harmony In the scheme of loving the people, there are the connected ethics of self cultivation-regulating the family(修身齊家) and the connected ethics of regulating the family-ordering the state(齊家治國) by effect of self-cultivation.

A Study of Segmental and Syllabic Intervals of Canonical Babbling and Early Speech

  • Chen, Xiaoxiang;Xiao, Yunnan
    • Cross-Cultural Studies
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    • v.28
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    • pp.115-139
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    • 2012
  • Interval or duration of segments, syllables, words and phrases is an important acoustic feature which influences the naturalness of speech. A number of cross-sectional studies regarding acoustic characteristics of children's speech development found that intervals of segments, syllables, words and phrases tend to change with the growing age. One hypothesis assumed that decreases in intervals would be greater when children were younger and smaller decreases in intervals when older (Thelen,1991), it has been supported by quite a number of researches on the basis of cross-sectional studies (Tingley & Allen,1975; Kent & Forner,1980; Chermak & Schneiderman, 1986), but the other hypothesis predicted that decreases in intervals would be smaller when children were younger and greater decreases in intervals when older (Smith, Kenney & Hussain, 1996). Researchers seem to come up with conflicting postulations and inconsistent results about the change trends concerning intervals of segments, syllables, words and phrases, leaving it as an issue unresolved. Most acoustic investigations of children's speech production have been conducted via cross-sectional designs, which involves studying several groups of children. So far, there are only a few longitudinal studies. This issue needs more longitudinal investigations; moreover, the acoustic measures of the intervals of child speech are hardly available. All former studies focus on word stages excluding the babbling stages especially the canonical babbling stage, but we need to find out when concrete changes of intervals begin to occur and what causes the changes. Therefore, we conducted an acoustic study of interval characteristics of segments and words concerning Canonical Babble ( CB) and early speech in an infant aged from 0;9 to 2;4 acquiring Mandarin Chinese. The current research addresses the following two questions: 1. Whether decreases in interval would be greater when children were younger and smaller when they were older or vice versa? 2. Whether the child speech concerning the acoustic features of interval drifts in the direction of the language they are exposed to? The female infant whose L1 was Southern Mandarin living in Changsha was audio- and video-taped at her home for about one hour almost on a weekly basis during her age range from 0;9 to 2;4 under natural observation by us investigators. The recordings were digitized. Parts of the digitized material were labeled. All the repetitions were excluded. The utterances were extracted from 44 sessions ranging from 30 minutes to one hour. The utterances were divided into segments as well as syllable-sized units. Age stages are 0;9-1;0,1;1-1;5, 1;6-2;0, 2;1-2;4. The subject was a monolingual normal child from parents with a good education. The infant was audio-and video-taped in her home almost every week. The data were digitized, segments and syllables from 44 sessions spanning the transition from babble to speech were transcribed in narrow IPA and coded for analysis. Babble was coded from age 0;9-1;0, and words were coded from 1;0 to 2;4, the data has been checked by two professionally trained persons who majored in phonetics. The present investigation is a longitudinal analysis of some temporal characteristics of the child speech during the age periods of 0;9-1;0, 1;1-1;5, 1;6-2;0, 2;1-2;4. The answer to Research Question 1 is that our results are in agreement with neither of the hypotheses. One hypothesis assumed that decreases in intervals would be greater when children were younger and smaller decreases in intervals when older (Thelen,1991); but the other hypothesis predicted that decreases in intervals would be smaller when children were younger and greater decreases in intervals when older (Smith, Kenney & Hussain, 1996). On the whole, there is a tendency of decrease in segmental and syllabic duration with the growing age, but the changes are not drastic and abrupt. For example, /a/ after /k/ in Table 1 has greater decrease during 1;1-1;5, while /a/ after /p/, /t/ and /w/ has greater decrease during 2;1-2;4. /ka/ has greater decrease during 1;1-1;5, while /ta/ and /na/ has greater decrease during 2;1-2;4.Across the age periods, interval change experiences lots of fluctuation all the time. The answer to Research Question 2 is yes. Babbling stage is a period in which the children's acoustic features of intervals of segments, syllables, words and phrases is shifted in the direction of the language to be learned, babbling and children's speech emergence is greatly influenced by ambient language. The phonetic changes in terms of duration would go on until as late as 10-12 years of age before reaching adult-like levels. Definitely, with the increase of exposure to ambient language, the variation would be less and less until they attain the adult-like competence. Via the analysis of the SPSS 15.0, the decrease of segmental and syllabic intervals across the four age periods proves to be of no significant difference (p>0.05). It means that the change of segmental and syllabic intervals is continuous. It reveals that the process of child speech development is gradual and cumulative.

A numerical study of pillar reinforcing effect in underground cavern underneath existing structures (지하공간하부 지하저류공동에서의 필라 보강효과에 관한 수치해석적 연구)

  • Seo, Hyung-Joon;Lee, Kang-Hyun;Han, Shin-In;Lee, In-Mo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.14 no.5
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    • pp.453-467
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    • 2012
  • Usage of underground space is increasing at metropolitan city. More than 90% of flood damages have occurred at downtown of metropolitan cities. In order to prevent and/or minimize the flood-induced damage, an underground rainwater detention cavern was proposed to be built underneath existing structures. As for underground caverns to be built for flood control, multi-caverns will be mostly adopted rather than one giant cavern because of stability problem. Because of the stress concentration occurring in the pillars between two adjacent caverns, the pillar-stability is the Achilles' heel in multi-caverns. So, a new pillar-reinforcing technology was proposed in this paper for securing the pillar-stability. In the new pillar-reinforcing technology, reinforced materials which are composed of a steel bar and PC strands are used by applying pressurized grouting, and then, by applying the pre-stress to the PC strands and anchor body. Therefore, this new technology has an advantage of utilizing most of the strength that the in-situ ground can exert, and not much relying on the pre-cast concrete structure. The main effect of the pressurized grouting is the increase of the ground strength and more importantly the decrease of stress concentration in the pillar; that of the pre-stress is the increase of the ground strength due to the increase of the internal pressure. In this paper, ground reinforcing effects were verified the stress change in pillar is obtained by numerical analysis at each construction stage. From these results, the effects of pressurized grouting and pre-stress are verified.

Assessment of Variable Characteristics in Water Quality of the Supply Systems in the Building (건축물내 급수설비의 수질변화 특성과 영향력 평가)

  • Lee, H.D.;Hwang, J.W.;Bae, C.H.;Kim, S.J.
    • Journal of Korean Society on Water Environment
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    • v.20 no.4
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    • pp.313-320
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    • 2004
  • In this study, variable characteristics of drinking water and the influences on underground water reservoirs, rooftop water tanks, and service water pipes in the building were assessed. The influence of underground water reservoir material and water capacity on water quality also were assessed. The results are the following as; First of all, the drinking water passing through underground water reservoirs or service water pipes in the building, averagely metal component concentration more increased from percent of 41.3 to percent of 74.2 totally than other items of water quality. On the other hand, both residual chlorine and total solid highly decreased 65.6 percent and 35.3 percent, respectively. Therefore, it was thought that water quality could be getting worse for microorganism re-growth by residual chlorine reduction, and total solid also could be a cause for extraneous matters accumulated in water reservoir. Secondly, the variations on water quality of each stage for water supply system in the building were higher in water service pipes connected from rooftop water tanks to the tap than in underground water reservoirs. In addition to, among of twelve items on water quality, ten items on water quality except dissolved oxygen and residual chlorine increased. Therefore, it was thought that the influence of water service pipes connected from rooftop water tanks to the tap on water quality were higher than other stages of water supply system in the building. Thirdly, in case of materials of underground water reservoir, it was likely that the variation on water quality by stainless steel and concrete materials got some similar. In case of water capacity, the variations on water quality of underground water reservoirs over $1,000m^3$ higher than those under $1,000m^3$. That reasons was likely that the retention time(49.72 hours averagely) of underground water reservoirs over $1,000m^3$ was two times longer than it of those under $1,000m^3$(23.37 hours). Therefore, it was thought that the influence on water quality by materials were some similar, but in case of water capacity, the influence of underground water reservoirs were higher.

A Study on the Female Adolescent's Experiences with Traumatic Domestic Violence (청소년기 여성의 가족폭력 피해에 관한 연구)

  • Kim, Kyung Hee;Kwon, Hye Jin;Choi, Mi Hye;Chung, Yeon Kang
    • Journal of the Korean Society of School Health
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    • v.9 no.2
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    • pp.205-221
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    • 1996
  • This study is designed to contribute to the intervention of adolescent domestic violence by understanding the experience of the victims, better. The data were collected through a series of interviews with 3 subjects singled out at each stage of research. With the permission of the subjects, the interviews were recorded and transcribed. The interviews lasted from two and a half to 8 hours. The data were analyzed in the framework of grounded theory as mapped out by Strauss & Corbin (1990). The major findings of this research are as follows : The core category was found to be the adaptation of "Jitnulim" or "Being suppressed". The sub-categories identified in the process of grounded data analysis were 'roughness', 'wildness', 'driving', 'challenging', 'being strapped', 'being pressed', 'erupting', 'being horrified', 'being hardened', 'being connected', 'being seen', 'being helpful', being led', 'sprouting', 'being off', 'being cast out', 'shaking off', 'getting out', 'covering-up', 'waiting', 'ruling', 'common placeness', 'overcoming', 'getting united', 'fa11ing behind', 'falling in', 'being mixed up', 'ruthlessness', 'estrangement', 'difficulty', 'being overwhelmed', 'feeling regreful', 'being pressed', 'hesitating', and 'shying off'. These categories were again grouped into 11 categories including 'threatening', 'straightjacketing', 'alliance', 'phenomenon', 'pattern of support', 'system of support', 'challenging', 'calming-down', 'being relieved', 'being hardened and entangled', 'being entangled'. The following four theses were confirmed on the basis of the repetitive relation: 1) If the episodes of violence are frequent and serious, with the resulting straightjacketing being stronger the victim's family relations are coherent and the subject's support pattern is highly mature. Concrete the responses to the straighjacketing resulted in a'calming-down' which gradually relieved. 2) If the episodes of violence were frequent and serious, with the resulting straightjacketing being strong the victim's family relations and incoherent and the subjects supporter is immature but strong the support type is superficial and the responses to the straightjacketing result in a bouncing-off which gets entangled with the passage of time. 3) If the episodes of the violence are frequent and serious, the straighljacketing is strong, but the family relations are and the subject's support system is mature and strong the responses to the straightjacketing result in a calming-down which gets partly relieved but partly entangled. 4) If the episodes of the violence are frequent and serious with the resulting straightiacketing being strong, the victim's family relations are incoherent, the subject's support system is immature, and the support type is immature the responses to the straightjacketing result in a 'bouncing-off' which gets entangled and partly hardened with time.

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International Cooperation Plan for DMZ World Peace Park: Focusing on NGO's international solidarity and support (DMZ 세계평화공원 조성을 위한 국제공조 방안: NGO의 국제연대 활동과 지원을 중심으로)

  • Suh, Kyung-Do
    • Journal of Digital Convergence
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    • v.14 no.12
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    • pp.645-655
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    • 2016
  • The purpose of this study is to analyze the roles and functions of NGO 's International Solidarity in the establishment of' DMZ World Peace Park ', the mechanism of operation, and the policy formation of NGO' s international solidarity. The establishment of the DMZ World Peace Park is a matter that can be achieved as a result of dialogue efforts between the two parties based on the agreement between the DPRK and the ROK government, but should take a more relaxed approach to the process issues in order to achieve such results And should be done in a long-term, step-by-step plan. In the process of realizing this, South Korea's own efforts alone are difficult, and it is necessary to seek various channels of dialogue with the international community so that North Korea can have dialogue negotiations. This will be the role of NGO, It should be noted. As a result, in order to establish 'DMZ World Peace Park', it is necessary to establish concrete road map of DMZ World Peace Park. In the first stage, it is necessary to organize and operate 'DMZ World Peace Park Promotion Committee' under the directorship of the President or Prime Minister, It is necessary to select candidates, to appeal to North Korea and to support the international community, and to participate voluntarily by the private sector. Phase 2 requires final settlement. Phase 3 will require a step-by-step road map, such as rapid construction of the Peace Park, expansion of peaceful use of the DMZ, and expansion of ecology, history and cultural tourism in the DMZ border area.

Quantification of the CO2 Footprint in Residential Construction

  • Don Mah;Juan D. Manrique;Haitao Yu;Mohamed Al-Hussein;Reza Nasseri
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.525-536
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    • 2009
  • The current residential process adheres to a traditional method of construction involving wood framing on-site on poured concrete foundations which has been widely applied in North America. A conventional residential construction process can include seventeen distinct stages ranging from stake-out to pre-occupancy inspection. The current practice possesses short comings including high construction material wastes, long scheduling timelines, adverse weather conditions, poor quality, low efficiencies and negative environmental impacts from transportation and equipment use. Over CAN $5 billion dollars was spent in the construction sector during 2007 in Canada. Previous findings in CO2 emissions during the construction process of a conventional dwelling emphasize more than 45 tonnes of CO2 emissions. Hence, in Alberta alone during 2007, almost 50,000 residential units would release more than two million tonnes of CO2. These numbers demonstrate the economical and environmental impact in building construction and its relationship with CO2 emissions. The aim of this paper is to quantify the CO2 emissions from the current residential construction process in order to establish the baseline for CO2 emission reduction opportunities. The quantification collection methodology will be approached by identifying the seventeen various stages of construction and quantifying the contributions of CO2 from specific activities and their impacts of work for each stage. The approach of separating these into separate stages for collection will allow for independent opportunities for analysis from various independent contractors from the entire scope of work. The use of BIM will be implemented to efficiently quantify CO2 emissions. Based on the CO2 quantification baseline, emission reduction opportunities such as an industrialized construction process will be introduced that allows homebuilders to reduce the environmental and economical impact of home construction while enabling them to produce higher quality, more energy efficient homes in a safer and shorter period of time.

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The Effects of Sex Education on the Primary Schooler's Knowledge and Attitude about Sex (성교육이 국민학생의 성지식과 성태도에 미치는 효과)

  • Kim, Jin-Son
    • Women's Health Nursing
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    • v.1 no.2
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    • pp.200-221
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    • 1995
  • The confusion of the sense of value on sex is increasing because of the rapid change in social-cultural environment. Also due to a rise in the standard of living, the age of adolescence is getting lower, and so the second sexual marks appear to primary schoolers. At this time in the aspect of the education for the whole man, it's very important for primary schoolers to acquire right knowledge and desirable attitude on sex so that can overcome psychological instability caused by physical growth, be responsible for their behaviors and lead happy lives. This study was made to find out the effects of sex education for the primary schoolers' knowledge and attitude about sex. The study was designed as simulated control group pretest-posttest design, which only pretest was practiced to control group and after sex education only posttest was practiced to experimental group. The data was collected for 18 days from March 13, 1995 to March 31, 1995. The subjects of this study were 130 six-graders in a private primary school in seoul. The control group and experimental group were composed of 65 pupils, each. Sex education consisted of lecture and discussion and the materials were this researcher's own made, 'How do I grow? and related OHP film and video. This education was practiced 40 minutes at a time, at intervals of 2-4 days' six times during 3weeks. For sex knowledge tools, 20 item questionaries on the base of related reference books and contents of this study were used. For sex attitude tools, this researcher's own made 13 item questionaries were used which were revised and complemented and laying stress on the reference books. The data was analyzed through pc-SAS program. The homogeneity test in terms of the general characteristics of experimental and control group was analyzed through $x^2$-test and t-test. And the difference in the primary schoolers' score on knowledge and attitude about sex before and after the sex education was analyzed through t-test and ANCOVA. The results of this study are as follows : 1. The result of the homogeneity test in terms of the general characteristics of the experimental and control group showed that there were significant differences in economic standard($x^2$=2.92, P=0.052) and brotherly ties($x^2$=3.78, P=0.052). 2. Hypothesis 'After sex education, the score of primary schoolers' sex knowledge will be higher than before. 'showed statistically significant difference.(t=11.99, P=.0001) Sex education was practiced under control over subjective view of economic standard and brotherly ties which showed significant difference at the homogeneity test in terms of the general characteristics between the two groups. After this education, the results of comparing the score of primary schoolers' sex knowledge also showed significant difference between the two groups. So hypothesis I was supported since primary schoolers to have education showed noticeable results in the sex knowledge score. (F=16.52, P=.0001) 3. Hypothesis 'After sex education, primary schooler's sex attitude score will be higher than before' showed statistically significant(t=5.08, P=.0001) Sex education was practiced, too, under control over subjective view of economic standard and brotherly ties which showed significant difference at the homogeneity test in terms of the general characteristics between the two groups. Bat this time the results of comparing the primary schoolers' sex attitude showed no significant difference between the two groups. So hypothesis II was rejected since for primary schoolers to have sex education showed no noticeable results in sex attitude score. (F=3.52, P=.0628) These results of the study show that sex education gives affirmative change to the primary schooler's sex knowledge, bat short periods' sex education doesn't give any change to the sex attitude. For the establishment of the pupils' desirable sex attitude, systematic and concrete sex education fit for the pupils' developing stage should be practiced over a long period of time.

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