• 제목/요약/키워드: cast

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Characteristics of defect on segmental lining of TBM tunnel in operational subway (운용중인 국내 지하철 TBM터널의 세그먼트라이닝 결함특성 분석)

  • Choo, Jinho;Lee, DongHun;Noh, EunChul
    • Journal of Korean Tunnelling and Underground Space Association
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    • 제24권1호
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    • pp.109-128
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    • 2022
  • The precise inspection for safety and diagnosis (PISD) of tunnel has been conducted by the special act on safety control of public structures. However, the present assessment for the segmental lining of TBM tunnel has limitation such as: NDTs for integrity, segmental configuration for field inspection, and consideration for jacking system. Even if the number of TBM tunnel is less than 1% of enrolled facility in FMS, more attention to maintenance should be necessary due to its usage such as multi-use facility and national important facility. Compared to NATM tunnel, excavated by drilling and blasting and then installed lining by cast-in-place within 6~12 m, TBM tunnel is cut out ground by disk and cutter-bit and then assembled 7 pieces of precast segment, 1.2~1.4 m wide. Different features of design, construction, and maintenance should be considered to be more exact evaluation of TBM tunnel. The characteristics of defect is categorized and analyzed with 11 operational TBM tunnels in domestic subway. To be more comprehend various particular defects, foreign studies have been also adapted. Crack and leakage are categorized in 7 patterns. Breakage/spalling and corrosion are also grouped into 3 patterns. Patterned defects or damages are fed back in design, construction, and are useful guidelines for maintenance stage in future.

Estimation of Appropriate Reinforcement Length of Casing for the Pile of Pile Bent System through Numerical Analysis (수치해석을 통한 단일형 현장타설말뚝 외부강관의 적정 보강길이 산정)

  • Yang, Wooyeol;Kim, Wanho;Lee, Kangil
    • Journal of the Korean GEO-environmental Society
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    • 제22권6호
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    • pp.5-15
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    • 2021
  • One of the construction methods applied as a pier foundation type is a single type cast-in-place pile. In applying a pile bent system as a foundation type, the main concern in designing can be said to secure the lateral bearing capacity of pile structure in system. In addition, to increase the rigidity of the pile structure, a method of increasing the lateral bearing capacity by reinforcing the pile structure with a casing has been used. However, although the reinforcing effect and appropriate reinforcing length of casing may vary depending on the soil conditions, there is insufficient studies on this, and for this reason, the entire pile structure in a pile bent system is reinforced with a casing, in the field. In addition, if the length of the entire pile is reinforced with a casing, it may lead to delays in construction and increase in construction costs. That is, in order to more effectively reinforce the pile structure with a casing, it is necessary to study the lateral bearing characteristics of the reinforced pile structure in system. And it should be determined the appropriate reinforcing length of the casing from the evaluated bearing characteristics. Therefore, in this study, the lateral bearing characteristics of piles applied with the reinforcing length of casing for each condition were evaluated through a numerical analysis. And, based on the analysis results, the appropriate reinforcing length of casing was proposed. As a result of the study, it was found that in order to effectively increase the lateral bearing capacity of pile structure, the reinforcing length of casing should be applied twice the influence range of the bending behavior of the pile, 1/β.

A Study on Expression of the Film (2019) : Focusing on Genre-Shifting Characters and Actors' Acting (영화 <기생충>(2019)의 표현성 연구 : 장르를 변주하는 캐릭터와 배우의 연기를 중심으로)

  • Lee, A-Young
    • Journal of Korea Entertainment Industry Association
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    • 제14권6호
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    • pp.77-89
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    • 2020
  • The film "Parasite" portrays Korea's history and its present in a space that clearly represents the real world's hierarchy as a vertical structure. It demonstrates the problems of an insurmountable reality and the elements of various conflicts occurring below the surface of Korean society through a complex mix of human emotions and relationships. The most realistic yet unrealistic characters cross boundaries between being victims and perpetrators, defamiliarizing ordinary scenes from everyday life through their small mistakes, strange obsessions, bizarre behavior, anxious psychology, and desperate struggles. This study analyzes the expression of the film "Parasite" through its characters with the belief that the film expresses director Bong Joon-ho's consistent cinematic philosophy of taking reality beyond the traditional rules of film genres. By doing so, Bong creates a feature of the expression that shifts genres as the characters' personalities amplify related behaviors, conflicts and questions, and that this is the core of the unique nuance and distinct humor of this film. In addition, the personalities of the characters interact with all the film's elements (cinematic techniques, space, props, etc.), evoking effects of various meanings, which are transmitted through the actors'images and acting. In this respect, the study analyzes how the actors were cast in order to realistically reproduce the characters of the actors, how their acting was harmonized with the film's elements, and its features as well as how they were expressed.

A Study on Various Sizes and Volumes of the Palate among the Korean Population in Mixed Dentition (한국 인구집단에서 부정교합 환아의 구개의 크기 및 용적에 관한 연구)

  • Jimyung, Choi;Jisun, Shin;Miran, Han;Junhaeng, Lee;Jongsoo, Kim;Jongbin, Kim
    • Journal of the korean academy of Pediatric Dentistry
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    • 제49권3호
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    • pp.329-339
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    • 2022
  • The purpose of this study was to compare the palatal dimensions (volume, width, length, and height) in different malocclusions (Class I, II, and III) in mixed dentition using a three-dimensional digital scanner. The study was performed on 30 selected casts from 1400 casts that were taken at the Department of Pediatric Dentistry at Dankook University. Casts consisted of Class I, II, and III malocclusion groups in Hellman's dental age IIIA. The mean age was 8 years and 6 months ± 11 months. Each cast was scanned by three-dimensional digital scanner, Medit T710 (Medit, Seoul, Korea), and shaped into the three-dimensional image and calculated palatal dimensions using the Plan T program (SMD solution, Seoul, Korea). The values were statistically compared and evaluated by Kruskal-Wallis followed by the Mann-Whitney test. According to our results, subjects with Class II malocclusion showed lower palatal width and longer palatal length compared to those with Class I and Class III. For palatal height, Class III malocclusion subjects in mixed dentition exhibited a larger number than Class II and Class I. Lastly, for palatal volume, compared to other malocclusions, Class III showed higher results; however, there were no significant differences. The form of the palate differs in types of malocclusions and understanding of these differences is important in clinical significance. Based on this study, the understanding of the relationship between the shape of the palate and the skeletal pattern provides useful information about orthodontic treatment plans, early diagnosis of malocclusion, and morphological integration mechanisms. Orthopedic treatment in the maxilla should be performed during early and intermediate mixed dentition to enhance treatment efficiency.

A Study on the Field Application of High Strength Joint Buried Pile Retaining Wall Method (고강도 결합 매입말뚝 흙막이 공법의 현장적용성 검토에 관한 연구)

  • Lee, Gwangnam;Kim, Daehyeon
    • The Journal of Engineering Geology
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    • 제32권4호
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    • pp.671-684
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    • 2022
  • This study verified the stability of a high-strength combined buried pile retaining wall and its applicability in the field. A cast-in-place (C.I.P) retaining wall and the high-strength combined embedded pile retaining wall were compared and analyzed numerically. The numerical analysis assessed the ground behavior and stability (and thus field applicability) of a high-strength combined buried pile retaining wall using data measured in the field. The experimental results showed that the cross-sectional force and displacement of the high-strength bonded pile retaining wall were reduced by 13.6~19.7%, the shear force increased by 0.7~4.7%, and the bending moment increased by 4.5~8.8% relative to the values for the C.I.P retaining wall. Examination of the amount of subsidence in the ground around the excavation showed that the maximum settlement of the C.I.P retaining wall was 46.89 mm and that at the high-strength combined buried pile retaining wall was 39.37 mm. Overall, designing a high-strength combined embedded pile retaining wall by applying the maximum bending moment and shear force calculated using the elastic beam method to the site ground was shown to achieve the safety of all members, as member forces were generated within the elastic region.

On-Site Construction Method for U-Girder with Pre-tension and Verification of Analytical Performance of Anchoring Block (프리텐션 U형 거더 현장 제작 방법 및 정착 블록 해석적 성능 검증)

  • Park, Sangki;Kim, Jaehwan;Jung, Kyu-San;Seo, Dong-Woo;Park, Ki-Tae;Jang, Hyun-Ock
    • Journal of Korean Society of Disaster and Security
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    • 제15권3호
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    • pp.67-77
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    • 2022
  • In South Korea, U-type girder development was attempted as a means to increase the length of I-type girder, but due to the large self-weight according to the post-tension method, the application of rail bridges of 30m or less is typical. There are not many examples of application of pre-tension type girder. This study does not limit the post-tension method, but applies the pre-tension method to induce a reduction in self-weight and materials used due to the reduction of the cross-section. In addition, we intend to apply the on-site pre-tensioning method using the internal reaction arm of the U-type girder. The prestressed concrete U-type girder bridge is composed of a concrete deck slab and a composite section. Compared to the PSC I-type, which is an open cross-section because the cross section is closed, structural performance such as resistance and rigidity is improved, the safety of construction is increased during the manufacturing and erection stage, and the height ratio is reduced due to the reduction of its own weight. Therefore, it is possible to secure the aesthetic scenery and economical of the bridge. As a result, it is expected that efficient construction will be possible with high-quality factory-manufactured members and cast-in-place members. In this paper, the introduction of the pre-tension method on-site and the analytical performance verification of the anchoring block for tension are included.

Selection of Artificial Sand Suitable for Manufacturing Steel Castings through Evaluation of Various Foundry Sand Properties (각종 주물사의 특성과 주강품 주조에 적합한 인공사 선택)

  • Gwang-Sik Kim;Jae-Hyung Kim;Myeong-Jun Kim;Ji-Tae Kim;Ki-Myoung Kwon;Sung-Gyu Kim
    • Journal of Korea Foundry Society
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    • 제43권3호
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    • pp.107-136
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    • 2023
  • Natural silica sand was commonly used for sand casting of cast steel products, and chromites sand was used to suppress seizure defects due to the lack of thermal properties of silica sand. However there are disadvantages such as deterioration by repeated use, system sand mixing problem, difficulty separating and removing, increased during mold according to high density and to being waste containing chrome. Recently, industrial waste reduction and atmospheric environment improvement have been highlighted as important tasks in the casting industry. In order to solve the problems that occur when using foundry Sand and to improve the environment of casting factories, various artificial sands that can be applied instead of natural silica sand have been developed and introduced. Artificial sands can be classified into artificial sand manufactured by the electric arc atomization or gas flame atomization, artificial sand manufactured by the spray drying & sintering process, artificial sand manufactured by the sintering & crushing process and exhibit different physical properties depending on the type of raw-minerals and manufacturing method. In this study, comparative evaluation tests were conducted on the physical properties of various foundry sands, mold strength, physical durability, thermal durability, and casting test pieces. When comprehensively considering the actual amount of molding sand used according to density, the mold strength according to the shape of sand, the physical and thermal durability of foundry sand, and the heat resistance characteristics of foundry sand, 'Molten artificial sand A1' or 'Molten artificial sand B' is judged to be the most suitable spherical artificial sand for casting of heavy steel castings.

Studies on the Contemporary Trends of Utilitarianism (현대 공리주의 동향에 대한 연구)

  • Kang, Joonho
    • Journal of Korean Philosophical Society
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    • 제93호
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    • pp.175-199
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    • 2011
  • The development of contemporary utilitarianism can be taken to be an aggregation of many attempts to surmount the limitations of classical utilitarianism. In these attempts, contemporary utilitarianism suggests alternatives to 'hedonism' and 'act-utilitarianism' which have been regarded as the common essential elements of classical utilitarianism. First, contemporary utilitarianism replaces the concept of 'happiness' or 'pleasure' in the classical utilitarianism with that of 'desire-fulfillment' or 'preference-satisfaction'. Through this replacement, contemporary utilitarianism tries to avoid the skeptical challenge to the mental state theory inherent in the classical concept of utility, and also to provide a more extensive conception of utility for a more satisfactory explanation of human welfare. Second, the development of rule-utilitarian theories which can evade the criticisms about 'counter-productivity' and 'counter-intuitiveness' of act-utilitarianism constitutes another important trend of contemporary utilitarianism. Characteristically, rule-utilitarian theories developed in the contemporary utilitarianism grope for some utilitarian system that can embrace socially accepted general norms. Lastly, contemporary utilitarianism responds to the criticisms related the problem of justice by reinterpreting the first principle of utilitarianism. This reinterpretation is an attempt to explain the egalitarian basis of utilitarianism through Bentham's dictum 'everyone counts for one, none for more than one'. It seems true that many influential criticisms in the latter half of 20th century cast a deep shadow on utilitarianism. But through the above attempt, contemporary utilitarianism proceeds to a better explanation of human welfare.

The Study for the Psychological Functioning of Casual Leisure: Compared with Serious Leisure (일상적 여가의 심리적 기능성에 대하여: 진지한 여가와의 비교를 중심으로)

  • Oh, Sae-Sook;Sohn, Young-Mi;Shin, Kyu-Lee;Oh, Kyung-A
    • 한국체육학회지인문사회과학편
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    • 제51권3호
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    • pp.273-284
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    • 2012
  • There is a large body of literature that studies serious leisure participants in a wide range of activities. By comparison, casual leisure has received scant attention, bearing few empirical studies. And serious leisure is often cast in an superior role in comparison with casual leisure for optimally healthy or beneficial leisure. The purpose of this study is to investigate the psychological functioning of 'casual leisure-serious leisure'. Especially, we pay more attention to reveal the positive functioning of casual leisure. It draws findings from the data of 291 university students. The results are as follows. First, in comparison with 'casual leisure group', 'serious leisure group' was showed a higher significant increase in leisure related functioning(leisure satisfaction and leisure benefits such as physical health, relationship and self-controlibility). However, There is no significant inter-group differences in 'self-life functioning variables(positive·negative self-esteem, happiness, quality of life)'. It implies even though serious leisure has more relation to positive leisure experiences, people maintain and enhance their self-esteem and experience satisfaction and happiness of their entire lives through casual leisure participation as much as serious leisure.

Kangjeungsan(姜甑山)'s Embracement of Chinese Myth and It's Meaning (강증산(姜甑山)의 중국신화 수용과 그 의미)

  • Jung, Jae-seo
    • Journal of the Daesoon Academy of Sciences
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    • 제25_1집
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    • pp.1-22
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    • 2015
  • This paper took Jeonkyeong (典經) of Daesunjinrihoe(大巡眞理會) as the basic text and studied how Kangjeungsan(姜甑山), the Sangje (上帝), had embraced Chinese myth in process of formation of his religious thought focusing on Yan Emperor(炎帝) Shennong(神農) myth and Shanrangang(禪讓) myth (namely Danchu myth). First when we examine the myth surrounding Kangjeungsan's birth, it deeply emraced a feeling-birth myth(感生神話), we could realize that this is a universe motif through myth of hero birth in East Asia. Further judging from the analysis of geographic space of Kangjeungsan's activity, it included a variety of mythical and Daoist related place names. I think this is because of the fact that birth place of Kangjeungsan and the surrounding area is the locality of Xian(仙) tradition where major characters of Danhak sect(丹學派) have been turned out, and that Korean way of Xian suppressed by the regulatory system has been widely rooted in the public. Especially it's interesting that Jeungsan, the pen name of Kangjeungsan, ambiguously connotes Siru mountain(甑山), a place of his training, and the spiritual realm of the 『Zhouyicantongqi(周易參同契)』. Then I examined the God of fire Shennong myth which has been actively admitted and embraced by Kangjeungsan. Kangjeungsan put the root of his pedigree on Shennong and there is a close affinity between Shennong and Dongyi(東夷) such as Buyeo(夫餘), Goguryeo(高句麗), etc. These Dongyi spirits are losers against the Chinese major myth and beings of ressentiment. At the same time the predecessor of Jiutianyingyuanleishengpuhuatianzun(九天應元雷聲普化天尊) who shares mythical characteristics with the God of fire Shennong was a formerly Taishi(太師) Wenzhong(聞仲) of Yin(殷) dynasty. He was defeated and died by Zhou(周) dynasty, and was deified. The fact that Kangjeungsan regarded himself as a descendent of Shennong and possessed divinity of Jiutianyingyuanleishengpuhuatianzun connotes that he represents all beings of ressentiment such as family of Yin and Dongyi. However, Kangjeungsan set a religious milestone by turning revenge for such ressentiment at tribe level into religious sublimation. At the end Shanrang myth which has been critically embraced by Kangjeungsan was reviewed. According to the existing Shanrang myth, Danchu(丹朱) was unworthy and not succeeded in the succession to the throne. Then good natured Emperor Shun(舜) succeeded to the throne from Emperor Yao(堯). However, the reality of Shanrang myth was a violent change of sovereign power and Danchu was a victim in the process of such violent change. Kangjeungsan shrewdly grasped the reality of ancient China and cast light on presence of Danchu. And he emphasized the need of religious sublimation of revenge, Haewon(解冤). His such awareness of culture had a close relation with revisionist standpoint of independent Danhak sect expressing a skeptical glance at systematic, commensurate and authentic historical view of Chinese civilization. And further Kangjeungsan cosmologically and causationally reinterpreted revenge of Danchu. He established a universal salvation theology which has a corresponsive connotation in regard to embracement of Shennong myth. In conclusion, embracement of Chinese myth by Kangjeungsan was a creative work of reinterpretation resulting in an inherent religious connotation through a process of appropriation, that is independent and selective introjection.