• Title/Summary/Keyword: Field Construction Process

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The Neutralization Treatment of Waste Mortar and Recycled Aggregate by Using the scCO2-Water-Aggregate Reaction (초임계이산화탄소-물-골재 반응을 이용한 폐모르타르와 순환골재의 중성화 처리)

  • Kim, Taehyoung;Lee, Jinkyun;Chung, Chul-woo;Kim, Jihyun;Lee, Minhee;Kim, Seon-ok
    • Economic and Environmental Geology
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    • v.51 no.4
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    • pp.359-370
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    • 2018
  • The batch and column experiments were performed to overcome the limitation of the neutralization process using the $scCO_2$-water-recycled aggregate, reducing its treatment time to 3 hour. The waste cement mortar and two kinds of recycled aggregate were used for the experiment. In the extraction batch experiment, three different types of waste mortar were reacted with water and $scCO_2$ for 1 ~ 24 hour and the pH of extracted solution from the treated waste mortar was measured to determine the minimum reaction time maintaining below 9.8 of pH. The continuous column experiment was also performed to identify the pH reduction effect of the neutralization process for the massive recycled aggregate, considering the non-equilibrium reaction in the field. Thirty five gram of waste mortar was mixed with 70 mL of distilled water in a high pressurized stainless steel cell at 100 bar and $50^{\circ}C$ for 1 ~ 24 hour as the neutralization process. The dried waste mortar was mixed with water at 150 rpm for 10 min. and the pH of water was measured for 15 days. The XRD and TG/DTA analyses for the waste mortar before and after the reaction were performed to identify the mineralogical change during the neutralization process. The acryl column (16 cm in diameter, 1 m in length) was packed with 3 hour treated (or untreated) recycled aggregate and 220 liter of distilled water was flushed down into the column. The pH and $Ca^{2+}$ concentration of the effluent from the column were measured at the certain time interval. The pH of extracted water from 3 hour treated waste mortar (10 ~ 13 mm in diameter) maintained below 9.8 (the legal limit). From XRD and TG/DTA analyses, the amount of portlandite in the waste mortar decreased after the neutralization process but the calcite was created as the secondary mineral. From the column experiment, the pH of the effluent from the column packed with 3 hour treated recycled aggregate kept below 9.8 regardless of their sizes, identifying that the recycled aggregate with 3 hour $scCO_2$ treatment can be reused in real construction sites.

Evaluation of mechanical characteristics of marine clay by thawing after artificial ground freezing method (인공동결공법 적용 후 융해에 따른 해성 점토지반의 역학적 특성 평가)

  • Choi, Hyun-Jun;Lee, Dongseop;Lee, Hyobum;Son, Young-Jin;Choi, Hangseok
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.21 no.1
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    • pp.31-48
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    • 2019
  • The artificial ground freezing (AGF) method is a groundwater cutoff and/or ground reinforcement method suitable for constructing underground structures in soft ground and urban areas. The AGF method conducts a freezing process by employing a refrigerant circulating through a set of embedded freezing pipes to form frozen walls serving as excavation supports and/or cutoff walls. However, thermal expansion of the pore water during freezing may cause excessive deformation of the ground. On the other hand, as the frozen soil is thawed after completion of the construction, mechanical characteristics of the thawed soil are changed due to the plastic deformation of the ground and the rearrangement of soil fabric. This paper performed a field experiment to evaluate the freezing rate of marine clay in the application of the AGF method. The field experiment was carried out by circulating liquid nitrogen, which is a cryogenic refrigerant, through one freezing pipe installed at a depth of 3.2 m in the ground. Also, a piezo-cone penetration test (CPTu) and a lateral load test (LLT) were performed on the marine clay before and after application of the AGF method to evaluate a change in strength and stiffness of it, which was induced by freezing-thawing. The experimental results indicate that about 11.9 tons of liquid nitrogen were consumed for 3.5 days to form a cylindrical frozen body with a volume of about $2.12m^3$. In addition, the strength and stiffness of the ground were reduced by 48.5% and 22.7%, respectively, after a freezing-thawing cycle.

A Study on Spatial Changes around Jangseogak(Former Yi Royal-Family Museum) in Changgyeonggung during the Japanese colonial period (일제강점기 창경궁 장서각(구 이왕가박물관) 주변의 공간 변화에 관한 연구)

  • Yee, Sun
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.39 no.4
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    • pp.10-23
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    • 2021
  • During the Japanese colonial period, the palaces of Joseon were damaged in many parts. Changgyeonggung Palace is the most demolished palace with the establishment of a zoo, botanical garden, and museum. During the Japanese colonial period, the palaces of Joseon were damaged in many parts. This study examined the construction process of Jangseogak(Yi Royal-Family Museum), located right next to the Jagyeongjeon site, which was considered the most important space in the Changgyeonggung residential area of royal family zone, through historical materials and field research. Built in 1911, Jangseogak is located at a location overlooking the entire Changgyeonggung Palace and overlooking the Gyeongseong Shrine of Namsan in the distance. Changes in the surrounding space during the construction of Jangseogak can be summarized as follows. First, in the early 1910s, the topography of the garden behind Jagyeongjeon and part of the Janggo were damaged to create the site of Jangseogak. The front yard was built in the front of Jangseogak, and a stone pillar was installed, and a staircase was installed to the south. In the process, the original stone system at the rear of Yanghwadang was destroyed, and it is presumed that Jeong Iljae and other buildings were demolished. Second, in the 1920s, many pavilions were demolished and the zoo and botanical gardens and museums were completed through leveling. After the Jangseogak was completed, the circulation of the Naejeon and surrounding areas was also changed. Cherry trees and peonies were planted in the flower garden around the front yard of Jangseogak and the stairs, and a Japanese-style garden was created between Yanghwadang and Jibbokheon. Third, in the 1930s, the circulation around Jangseogak was completed in its present form, and the museum, Jangseogak, Zoological and Botanical Gardens, and Changgyeonggung, which became a cherry tree garden, were transformed into a Japanese-style cultural park. After that, the surrounding space did not change much until it was demolished. The restoration of the present palace is a long-term, national project of the Cultural Heritage Administration. The results of this study will provide important data for the restoration plan of Changgyeonggung Palace in the future, and it is expected that it will provide additional information to related researchers in the future.

Development of teaching-learning lesson plan untilizing TAI model based on module, used in survey subject of construction department - By applying standard-based assessment system for technical subject (건설계열 측량교과에서 활용할 모듈 기반의 TAI 모형 적용 교수-학습 과정안 개발 - 전문교과 성취평가제를 적용하여)

  • Lee, Ju-Min;Jang, Young-Il;Park, Wan-Shin
    • 대한공업교육학회지
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    • v.38 no.2
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    • pp.89-113
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    • 2013
  • The study started from the point that learners should be basically equipped to quickly respond to changes in demand for future human resources efficiently and effectively, and an attitude to take part in learning voluntarily should thus be cultivated. To this end, the author applied the TAI model based on a module as a class strategy to solve problems related to several classes occurred in specialized high schools. This application of the TAI model was also motivated by the necessity for designing an appropriate teaching-learning method that encourages improvement of self-learning capacity, consistent learning motivation, and willingness rather than external factors. Through this work, the author aims to heighten the interest of learners and improve endurance in learning. The study results are as follows. First, the learning unit was structuralized as a module and then learning stages were proceeded with so that capacity to adapt to learning would improve. The achievement standard (learning goal) was structuralized in a module type by analyzing and reorganizing the textbook considering the link between the actual practice field and a curriculum based on subject characteristics. Through the process of module type learning stages, the student's capacity to ascertain characteristics of units and to adapt to learning both improved. Second, through application of a TAI model based on a module, Self-Directed Learning capacity and capacity to adapt to a new field improved. By applying the module, Self-Directed Learning could be accomplished more effectively than in the existing passive learning environment. By grafting cooperative learning of the TAI model, students had greater interest and achievement in classes, self-confidence and community consciousness, and an opportunity to broaden their thinking. In particular, improvement of self-confidence is effective in cultivating the capacity required in industrial society to transcend the learning of simple functions and knowledge, as well as the capacity to adapt to new environments. Third, by solving tasks focused on fields related to industrial sites, not only actual survey capacity but also additional capacity to identify and solve tasks through various experiences improved. Furthermore, it was helpful for students to have interest and motivation about their own life and learning to cultivate the qualities and capacity to adapt to the working world where new knowledge and technology rapidly change. Fourth, by applying a standard-based assessment system for technical subjects introduced in 2012 to model design for learning plans, clearer and more objective assessment criteria were arranged, and individual learning through instruction at each achievement level could be accomplished. This improved achievement level of individual learners was helpful in reaching achievement goals at specific levels by overcoming the disadvantages of cooperative learning in each group.

A study on the traditional salt-making of the Joolpo inlet area during the 18th and 19th century (18~19世紀 茁浦灣의 煮鹽 - 鹽場의 分布와 煮鹽法을 중심으로 -)

  • ;Hong, Keum-Soo
    • Journal of the Korean Geographical Society
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    • v.29 no.1
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    • pp.46-64
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    • 1994
  • Among every civilized people salt has been recognized as an essential foodstuff to the human society without which even man's survivor is unthinkable. The cultural-anthropological meaning of salt is estimated highly as well, and in geographical perspective salt itself symbolize regional interrelationship. Playing a decisive role in freeing innermost settlement from isolation, salt aiso made a contribution to expanding human habitats. This study tries to reconstruct historica geography of 18th and 19th century surrounding traditional salt-roasting (chayeom). The Joolpo Inlet area which is located on the mid-western coast in Honem Region is selected for study area. Established on the basis of optimum physical geographical conditions such as topography, climate and vegetation, salt-making of Joolpo Inlet area was run dynamically with the sudden turn of events in the 18-19th century which was chacterized as an age of transition from medieval society to modern one. In this paper the writer attempts to clarify mainly following three points: physical conditions and socio-economic background leading to the initiation and later development of roasting of salt in Joolpo Bay; distribution of saltworks; methods of saltmaking. Main points drawn from these analyses can be summarized as follows: of iron pan and cow-drawn tools rendered labour-saving and output growth. 1, Saltworks of Joolpo Inlet area in the 18-19th century were distributed evenly over Kobu, Puan, Mujang and Heungduck counties among which Kobu's was located in Puanmyon - a sort of exclave. All saltworks belonging to above four counties were clasified as most lucrative ones in Honam Region on government archives. In particular, Gumdang saltwork which belongs to Mujang county is noteworthy in that it was first introduced by one Paekje priest in 6th century and therefore it provides a clue to examine the history of salt-roasting of Joolpo Inlet area. In light of the fact that temple or monastery economy, regardless of East and West, has been closely connected with traditional industry, the case of Gumdang is not unusual. 2. The process of saltmaking follows this order: harrowing of salt field exposed to solar heat; construction of saltern mound with saline earth; acquiring of brine by leaching saline earth; roasting of salt. Salterns (saltworks) are consisted with various salt making facilities such as roasting shed, saltern mound, salt field, salt well) salt pit or brine pit) and seawater reservoir. Among them roasting shed which is constructed chiefly with hundreds of pieces of pine tree as a frame and with straw as roof and wall is customarily considered as an unit of saltwork. And inside it is saltpan made of two kinds of materials, that is iron pan or plaster pan. The area attached to one unit of roasting shed is approximately 1 ha, and that of saltern mound is a tenth of it.

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Clustering-based Hierarchical Scene Structure Construction for Movie Videos (영화 비디오를 위한 클러스터링 기반의 계층적 장면 구조 구축)

  • Choi, Ick-Won;Byun, Hye-Ran
    • Journal of KIISE:Software and Applications
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    • v.27 no.5
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    • pp.529-542
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    • 2000
  • Recent years, the use of multimedia information is rapidly increasing, and the video media is the most rising one than any others, and this field Integrates all the media into a single data stream. Though the availability of digital video is raised largely, it is very difficult for users to make the effective video access, due to its length and unstructured video format. Thus, the minimal interaction of users and the explicit definition of video structure is a key requirement in the lately developing image and video management systems. This paper defines the terms and hierarchical video structure, and presents the system, which construct the clustering-based video hierarchy, which facilitate users by browsing the summary and do a random access to the video content. Instead of using a single feature and domain-specific thresholds, we use multiple features that have complementary relationship for each other and clustering-based methods that use normalization so as to interact with users minimally. The stage of shot boundary detection extracts multiple features, performs the adaptive filtering process for each features to enhance the performance by eliminating the false factors, and does k-means clustering with two classes. The shot list of a result after the proposed procedure is represented as the video hierarchy by the intelligent unsupervised clustering technique. We experimented the static and the dynamic movie videos that represent characteristics of various video types. In the result of shot boundary detection, we had almost more than 95% good performance, and had also rood result in the video hierarchy.

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A Study on the Welding Amount Estimation System combined with 3D CAD Tool (3차원 CAD 통합형 용접물량 산출 시스템에 관한 연구)

  • Ruy, Won-Sun;Kim, Ho-Kyeong;Ko, Dae-Eun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.7
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    • pp.3184-3190
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    • 2013
  • These days, the great part of design processes in the field of ship or offshore manufacturing are planed and implemented using the customized CAD system for each ship-building companies. It means that all information for design and production could be extracted and reused at the useful other area cost considerable time and efforts. The representative example is the estimation of welding length and material amount which is demanded during the construction of ship or offshore structures. The proper estimation of welding material to be used and the usage of them at the stage of schedule planning is mostly important to achieve the seamless process of production and expect the costing in advance. This study is related to the calculation of welding length and needed material amount at the stage of design complete utilizing the CAD system. The calculated amount are classified according to welding position, stage, block, bevel and welding type. Moreover it is possible to predict the working time for welding operation and could be used efficiently for the cost management using the results of this research.

A Tracer Experiment of Sediment Transport Path Using Fluouescent-Tagged Sands (형광사를 이용한 표사이동경로 추적 실험)

  • Jeong, Sin-Taek;Jo, Hong-Yeon;O, Yeong-Min;Kim, Chang-Wan
    • Journal of Korea Water Resources Association
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    • v.32 no.5
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    • pp.547-555
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    • 1999
  • The economical manufacturing process of fluorescent sediments (FS) which makes use of the understanding of coastal sediment path has been suggested with respect to the Lagrangian viewpoint. First, the fluorescent liquids were made by the mixing of the fluorescent materials, acetone, and xylene. Second, the sediments collected in Gamami beach were desalinized by the freshwater washing, dried indoors to protect the fine-sediment scattering, and classified by the sieve analysis. Finally, the FS which have seven different colors were manufactured by the mixing of fluorescent liquids and prepared sediments. The FS were used to figure out the major sediment supply routes of the intake channel in the YoungKwang nuclear power plant. From the field experiments, it was shown that the sediments were suspended and dispersed by the strong seasonal NW wind and the tide, and the sediments in suspension were flowing into the intake channel due to very strong suction speed. All the FS injected in stations were detected in the channel sampling points, thus we concluded that the sediments in suspension and dispersion were flowing into the intake channel from all directions in adjacent coastal zone.

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A Study on the Experience Design Construction and Its Application Model (경험디자인의 구성과 적용 모형에 관한 연구)

  • 윤세균;김태균;채승진
    • Archives of design research
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    • v.16 no.4
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    • pp.289-298
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    • 2003
  • The 21st century could be called the age of Experience Economy associated with the importance to external and internal experience of product users. It needs the understanding of customer's needs in new point of view. In the area of design development, it requires the extensive application of experience from traditional method that was based on the style and usability to more advanced concept. To correspond to these changes, we need to explore new customer's value system for knowledge-information design and systematic approaches to experience system. The purpose of this research is to define the concept of 'experience' newly in the importance side of customer's life, form a clear definition of experience design and present the model of application system. Theoretical frameworks of this research are based on the Empiricism and John Dewey's theory. By applying these frameworks make dear the concept of experience concept and reanalysis the meaning and style in the perspective of design. In this process, we can extract the main factors that inducing the experience, create new application system and model again to the field of design. Application model can creates various experiences through supplying different experience style and factors for customer, make customer realize experience object. Experience designs offer optimal experience to users by making a plan and design experience to user's goal.

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Store Module Case Study of Traditional Market (전통시장 점포모듈 사례분석 연구)

  • Lee, Kyung-Sik;You, Yen-Yoo;Kim, Jung-Ryol
    • Journal of the Korea Convergence Society
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    • v.8 no.8
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    • pp.255-265
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    • 2017
  • The study analyzed previous studies on traditional markets and market modernization projects to analyze research trends and content related to traditional markets. Next, the study selected 4 traditional markets throughout the nation where there was promotion of market modernization projects to conduct field research and interviews about store modules, line of flow, facility configuration, and types of businesses. Empirical comparative analysis was conducted on construction hardware status through measurement and observation and data was collected on business environment and requirement characteristics by business type through interviews with merchant associations of the corresponding markets. Consistent standard was applied as much it was possible to comparatively analyze the 4 market modernization cases and on the unique characteristics of individual markets, the cause was determined in conjunction to the history of the business promotion process and regional characteristics. After the study, basic data to suggest guidelines in store modules by business type in traditional markets could be acquired and the study identified the facilities equipment standards that must be considered in future market modernization projects. Through this it will be possible to derive policy implications to minimize trial and error and guarantee business efficiency in future market modernization projects.