• Title/Summary/Keyword: Change of direction

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Shielding Design Optimization of the HANARO Cold Neutron Triple-Axis Spectrometer and Radiation Dose Measurement (냉중성자 삼축분광장치의 차폐능 최적화 설계 및 선량 측정)

  • Ryu, Ji Myung;Hong, Kwang Pyo;Park, J.M. Sungil;Choi, Young Hyeon;Lee, Kye Hong
    • Journal of Radiation Protection and Research
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    • v.39 no.1
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    • pp.21-29
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    • 2014
  • A new cold neutron triple-axis spectrometer (Cold-TAS) was recently constructed at the 30 MWth research reactor, HANARO. The spectrometer, which is composed of neutron optical components and radiation shield, required a redesign of the segmented monochromator shield due to the lack of adequate support of its weight. To shed some weight, lowering the height of the segmented shield was suggested while adding more radiation shield to the top cover of the monochromator chamber. To investigate the radiological effect of such change, we performed MCNPX simulations of a few different configurations of the Cold-TAS monochromator shield and obtained neutron and photon intensities at 5 reference points just outside the shield. Reducing the 35% of the height of the segmented shield and locating lead 10 cm from the bottom of the top cover made of polyethylene was shown to perform just as well as the original configuration as radiation shield excepting gamma flux at two points. Using gamma map by MCNPX, it was checked that is distribution of gamma. Increased flux had direction to the top and it had longer distance from top of segmented shield. However, because of reducing the 35% of the height, height of dissipated gamma was lower than original geometry. Reducing the 35% of the height of the segmented shield and locating lead 10cm from the bottom of the top cover was selected. After changing geometry, radiation dose was measured by TLD for confirming tester's safety at any condition. Neutron(0.21 ${\mu}Svhr^{-1}$) and gamma(3.69 ${\mu}Svhr^{-1}$) radiation dose were satisfied standard(6.25 ${\mu}Svhr^{-1}$).

CFD Analysis for Microclimate of Venlo Type Glasshouse with the Screen Height and Air-inflow Quantity (스크린설치높이·공기유입량 차이에 따른 벤로형 유리온실 미기상 CFD 유동해석)

  • Yang, Won Mo
    • Journal of Bio-Environment Control
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    • v.29 no.1
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    • pp.52-61
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    • 2020
  • The natural change of winter night temperature from 00:00 to 04:30 O'clock with the different height of thermal screen in a venlo type glasshouse (W59×L68×H5.9 m) was studied using computational fluid dynamics (CFD). At the early stage of CFD analysis, the room temperature decrease of glasshouse with the 5.9 m height of thermal screen were faster than it with the 4.1m height of thermal screen, but at 2 hr after analysis it was slower than in it with the 4,1m, the temperature difference was 0.6℃ after 4 hr. If we consider that turn on the heater when the temperature were decrease below 13℃ at 1hr after CFD analysis, it is good for energy saving in the glasshouse with the 4.1 m height of thermal screen rather than in it with the 5.9 m height, because of the temperature decrease were slow during 2 hrs after analysis. The airflow at the height of 2 m which were grown tomato were fast and wide in the glasshouse with the 5.9 m height thermal screen rather than in it with the 4.1 m, the speed difference was 0.034m·s-1 at 1hr after CFD analysis. The effect of temperature decrease in summer season were compared with the different height of shading screen from 12:00 to 14:30 O'clock. The height of shading screen were 5.7, 3.9 m, the gap of it were 30%. The air-inflow quantity by the fan with duct at lower part of venlo glasshouse was 0.67 ㎥·s-1 until 1hr and to increase 3 times of it from 1hr after analysis. The roof window were open 100%. Until 1hr of CFD analysis, the temperature in the 30% open of shading screen was 0.9℃ higher than in the none shading screen. From 13:00 O'clock when the air-inlet quantity to increase 3 times, the temperature in case 30% gap of shading screen were decreased compare with the none shading screen, the temperature difference was 0.5℃ at 14:30 O'clock. The temperature on the floor surface in case 30% gap of shading screen were lower with it's height increase, the temperature difference was 8℃ compare with none shading screen. The relative humidity difference were insignificant by the height and gap of shading screen.

Difference in the Set-up Margin between 2D Conventional and 3D CT Based Planning in Patients with Early Breast Cancer (조기유방암환자의 이차원치료계획과 삼차원치료계획의 방사선조사범위의 차이)

  • Jo, Sun-Mi;Chun, Mi-Son;Kim, Mi-Hwa;Oh, Young-Taek;Kang, Seung-Hee;Noh, O-Kyu
    • Radiation Oncology Journal
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    • v.28 no.3
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    • pp.177-183
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    • 2010
  • Purpose: Simulation using computed tomography (CT) is now widely available for radiation treatment planning for breast cancer. It is an important tool to help define the tumor target and normal tissue based on anatomical features of an individual patient. In Korea, most patients have small sized breasts and the purpose of this study was to review the margin of treatment field between conventional two-dimensional (2D) planning and CT based three-dimensional (3D) planning in patients with small breasts. Materials and Methods: Twenty-five consecutive patients with early breast cancer undergoing breast conservation therapy were selected. All patients underwent 3D CT based planning with a conventional breast tangential field design. In 2D planning, the treatment field margins were determined by palpation of the breast parenchyma (In general, the superior: base of the clavicle, medial: midline, lateral: mid - axillary line, and inferior margin: 2 m below the inframammary fold). In 3D planning, the clinical target volume (CTV) ought to comprise all glandular breast tissue, and the PTV was obtained by adding a 3D margin of 1 cm around the CTV except in the skin direction. The difference in the treatment field margin and equivalent field size between 2D and 3D planning were evaluated. The association between radiation field margins and factors such as body mass index, menopause status, and bra size was determined. Lung volume and heart volume were examined on the basis of the prescribed breast radiation dose and 3D dose distribution. Results: The margins of the treatment field were smaller in the 3D planning except for two patients. The superior margin was especially variable (average, 2.5 cm; range, -2.5 to 4.5 cm; SD, 1.85). The margin of these targets did not vary equally across BMI class, menopause status, or bra size. The average irradiated lung volume was significantly lower for 3D planning. The average irradiated heart volume did not decrease significantly. Conclusion: The use of 3D CT based planning reduced the radiation field in early breast cancer patients with small breasts in relation to conventional planning. Though a coherent definition of the breast is needed, CT-based planning generated the better plan in terms of reducing the irradiation volume of normal tissue. Moreover it was possible that 3D CT based planning showed better CTV coverage including postoperative change.

The Characteristic of Research Regulation in Recent Japanese Medical World (최근 일본의 의학계 연구규율의 특색)

  • Song, Young-mi
    • The Korean Society of Law and Medicine
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    • v.20 no.2
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    • pp.173-206
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    • 2019
  • This research examines the characteristic of regulation on Japanese clinical research in recent years. First, Japan has had a severe punishment policy on research misconduct like Korea, but, in recent days, Japan has changed the direction of research ethics policy from restriction to research publicness securement by educational training, in addition, Act of Clinical Research, effected April 2018, has recruited excellent researchers, and then integrated clinical research and medicine clinical trial through raising transparency of funding and integrating ethics screening by mandating announcement on funding information of clinical research. Second, Japan has integrated and organized ethics guideline from dual system that consists of ethics guideline on dynamic research(here after, referred to as 「dynamic guideline」) and ethics guideline on clinical research(here after, referred to as 「clinical guideline」) to ethics guideline on medical research aimed at human(here after, referred to as 「integrated guideline」), thus, it complements repetition and deficit of ethics guideline needed in clinical research and dynamic research, and it has risk evaluation system for protecting human subjects, and also it clarifies the concept of 「invasiveness」, a preliminary consideration of evaluation. 「Evaluation issue of risk and profit」, common contents of international regulation related clinical research, is the method to check whether the research is designed appropriately or not, this is the method for Institutional Review Board to decide whether the risk on human subjects could be justified, and also this is the important standard for future human subjects to participate in clinical trial. Therefore, it is meaningful to define 「invasiveness」 concept, a preliminary consideration of risk evaluation for human subjects. This research examines Japanese clinical trial focusing on change of awareness on prevention of research misconduct, efficiency improvement of research through research screening and integration of human subjects, and clarification and extension of range of 「invasiveness」 concept, a preliminary of risk evaluation to protect human subjects.

Change of Perception and New Methodology of Korean Cartoon Exhibition (한국만화전시의 인식변화와 새로운 방법론)

  • Kim, Jeung-Yeun
    • Cartoon and Animation Studies
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    • s.39
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    • pp.413-450
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    • 2015
  • Although cartoons have been recognized for their great potential and value, they have failed to bloom in Korea. This is because wrong perception and irregular distribution of cartoons have been repeated for the last several years. Presently, however, cartoons are escaping from chronic problems they have had for long and welcoming splendid chances now. From the mid- and late-1990's, there have been large-scale events having cartoons as their theme, and social recognition on cartoons is becoming more and more positive. Their contents are diversified, readers are increased, and they are escaping from stereotypes through harmony with other media. Lately, either large or small exhibitions for cartoons are being planned, and Korean cartoons are going overseas and producing exhibitions there. Particularly, visitors' appreciative eye is getting keener, and they begin to see them not as a genre underestimated as low culture like in the past but as a kind of art on which independent research is being actively conducted. One of the biggest factors that have allowed cartoons to be positioned as visual art is the form of exhibitions that combine them with other genres artistically. Especially the cartoon exhibitions being held these days are aggressively introducing various elements of the cartoon genre through the medium of exhibitions not just as a mere tool of seeing to help understand cartoon writers or works. The genre of cartoons is now regarded as an active subject that can reflect its own unique essence in this rapidly changing cultural environment and extend the range of it itself. The latest cartoon exhibitions are characterized by trans-genre and complex aspects in terms of their direction or organization according to the contents, space, or theme. This trend of cartoon exhibitions implies that they are subdividing, analyzing, and planning various factors not in a horizontal way that was centered around image as in the past. It means that cartoon exhibitions are evolving as a form of mobilizing, combining, and reproducing various methods. Although a number of cartoon exhibitions are being held with a variety of themes, there is still lack of research on cartoon exhibitions concerning their forms and contents. Therefore, this researcher sees cartoon exhibitions as a factor that allows cartoons to escape from negative recognition and examines various cartoon exhibitions, from Seoul International Cartoon Animation Festival to the ones that are recently held, to figure out the meaning of Korean cartoon exhibitions. Furthermore, this researcher will find out the factors of planning and popularity in international exhibitions or personal cartoon exhibitions being presently held and figure out new directions and potentials for Korean cartoon exhibitions based on that. To meet the needs of visitors whose expectations have become even higher, it is needed to try not just previous methods but experimental and original planning as well constantly. To realize that, it is necessary to keep providing a field of opportunity where cartoon works, cartoon writers, and visitors can communicate as in an exhibition. It is expected that this study will trigger research on cartoon exhibitions to be performed multilaterally and produce new discourse on cartoon exhibitions afterwards.

A Case Study on the UK Park and Green Space Policies for Inclusive Urban Regeneration (영국의 포용적 도시재생을 위한 공원녹지 정책 사례 연구)

  • Kim, Jung-Hwa;Kim, Yong-Gook
    • Journal of the Korean Institute of Landscape Architecture
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    • v.47 no.5
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    • pp.78-90
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    • 2019
  • The purpose of this study is to explore the direction of developing policies for parks and green spaces for inclusive urban planning and regeneration. By reviewing the status, budget, and laws pertaining to urban parks in Korea, as well as assessing the inclusivity of urban parks, this study revealed the problems and limitations in Korea as follows. First, the urban park system, which takes into account indicators such as park area per capita and green space ratio, is focused only on quantitative expansion. Second, the distribution of urban parks is unequal; hence, the higher the number of vulnerable residents, the lower the quality of urban parks and green spaces. Moreover, this study focused on the UK central government, along with the five local governments, including London, Edinburgh, Cardiff, Belfast, and Liverpool. Through an analysis of the contexts and contents establishing UK park and green space policies that can reduce socioeconomic inequalities while at the same time increase inclusiveness. This study discovered the following. The government's awareness of the necessity of tackling socioeconomic inequalities to make an inclusive society, the change in the urban regeneration policies from physical redevelopment to neighborhood renewal, and the survey and research on the correlation of parks and green spaces, inequality, health, and well-being provided the background for policy establishment. As a result, the creation of an inclusive society has been reflected in the stated goals of the UK's national plan and the strategies for park and green space supply and qualitative improvement. Deprived areas and vulnerable groups have been included in many local governments' park and green space policies. Also, tools for analyzing deficiencies in parks and methods for examining the qualitative evaluation of parks were developed. Besides, for the sustainability of each project, various funding programs have been set up, such as raising funds and fund-matching schemes. Different ways of supporting partnerships have been arranged, such as the establishment of collaborative bodies for government organizations, allowing for the participation of private organizations. The study results suggested five policy schemes, including conducting research on inequality and inclusiveness for parks and green spaces, developing strategies for improving the quality of park services, identifying tools for analyzing policy areas, developing park project models for urban regeneration, and building partnerships and establishing support systems.

Interpretation on Making Techniques of Some Ancient Ceramic Artifacts from Midwestern Korean Peninsula: Preliminary Study (한반도 중서부 출토 일부 고대 세라믹 유물의 제작기술 해석: 예비 연구)

  • Lee, Chan Hee;Jin, Hong Ju;Choi, Ji Soo;Na, Geon Ju
    • Journal of Conservation Science
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    • v.32 no.2
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    • pp.273-291
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    • 2016
  • Some ceramic artifacts representing time-wise from comb pattern pottery in the Neolithic Age to white porcelain in Joseon Dynasty were selected from 7 sites in the north and south area of Charyeong Mountain Range in order to making techniques interpretation and development process of ancient ceramics through physicochemical and mineralogical quantitative analysis. Studied pottery samples in the Prehistoric times showed trace of ring piling in soft-type, and pottery in the Three Kingdoms Period had both soft and hard-type but kettle-ware and storage-ware were made with ring piling, but table-ware was made by wheel spinning. Different from pottery after the Three Kingdom Period when refinement of source clay was high, pottery in the Neolithic Age and in the Bronze Age exhibited highly mineral content in sandy source clay, which showed a lot of larger temper than source clay. Groundmass of celadon and white porcelain almost did not reveal primary minerals but had high content of minerals by high temperature firing. Ceramic samples showed some different in major and minor elements according to sites irrespective of times. Geochemical behaviors are very similar indicating similar basic characteristics of source clay. However, loss-on-ignition showed 0.01 to 12.59wt.% range with a large deviation but it rapidly decreased moving from the Prehistoric times to the Three Kingdom Period. They have correlation with the weight loss due to firings, according to burning degree of source clay and detection of high temperature minerals, estimated firing temperatures are classified into 5 groups. Pottery in the Neolithic Age and in the Bronze Age belongs from 750 to $850^{\circ}C$ group; pottery in the Three Kingdom Period are variously found in 750 to $1,100^{\circ}C$ range of firing temperature; and it is believed celadon and white porcelain were baked in high temperature of 1,150 to $1,250^{\circ}C$. It seems difference between refinement of source clay and firing temperature based on production times resulted from change in raw material supply and firing method pursuant to development of production skill. However, there was difference in production methods even at the same period and it is thought that they were utilized according to use purpose and needs instead of evolved development simply to one direction.

Building a Korean Sentiment Lexicon Using Collective Intelligence (집단지성을 이용한 한글 감성어 사전 구축)

  • An, Jungkook;Kim, Hee-Woong
    • Journal of Intelligence and Information Systems
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    • v.21 no.2
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    • pp.49-67
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    • 2015
  • Recently, emerging the notion of big data and social media has led us to enter data's big bang. Social networking services are widely used by people around the world, and they have become a part of major communication tools for all ages. Over the last decade, as online social networking sites become increasingly popular, companies tend to focus on advanced social media analysis for their marketing strategies. In addition to social media analysis, companies are mainly concerned about propagating of negative opinions on social networking sites such as Facebook and Twitter, as well as e-commerce sites. The effect of online word of mouth (WOM) such as product rating, product review, and product recommendations is very influential, and negative opinions have significant impact on product sales. This trend has increased researchers' attention to a natural language processing, such as a sentiment analysis. A sentiment analysis, also refers to as an opinion mining, is a process of identifying the polarity of subjective information and has been applied to various research and practical fields. However, there are obstacles lies when Korean language (Hangul) is used in a natural language processing because it is an agglutinative language with rich morphology pose problems. Therefore, there is a lack of Korean natural language processing resources such as a sentiment lexicon, and this has resulted in significant limitations for researchers and practitioners who are considering sentiment analysis. Our study builds a Korean sentiment lexicon with collective intelligence, and provides API (Application Programming Interface) service to open and share a sentiment lexicon data with the public (www.openhangul.com). For the pre-processing, we have created a Korean lexicon database with over 517,178 words and classified them into sentiment and non-sentiment words. In order to classify them, we first identified stop words which often quite likely to play a negative role in sentiment analysis and excluded them from our sentiment scoring. In general, sentiment words are nouns, adjectives, verbs, adverbs as they have sentimental expressions such as positive, neutral, and negative. On the other hands, non-sentiment words are interjection, determiner, numeral, postposition, etc. as they generally have no sentimental expressions. To build a reliable sentiment lexicon, we have adopted a concept of collective intelligence as a model for crowdsourcing. In addition, a concept of folksonomy has been implemented in the process of taxonomy to help collective intelligence. In order to make up for an inherent weakness of folksonomy, we have adopted a majority rule by building a voting system. Participants, as voters were offered three voting options to choose from positivity, negativity, and neutrality, and the voting have been conducted on one of the largest social networking sites for college students in Korea. More than 35,000 votes have been made by college students in Korea, and we keep this voting system open by maintaining the project as a perpetual study. Besides, any change in the sentiment score of words can be an important observation because it enables us to keep track of temporal changes in Korean language as a natural language. Lastly, our study offers a RESTful, JSON based API service through a web platform to make easier support for users such as researchers, companies, and developers. Finally, our study makes important contributions to both research and practice. In terms of research, our Korean sentiment lexicon plays an important role as a resource for Korean natural language processing. In terms of practice, practitioners such as managers and marketers can implement sentiment analysis effectively by using Korean sentiment lexicon we built. Moreover, our study sheds new light on the value of folksonomy by combining collective intelligence, and we also expect to give a new direction and a new start to the development of Korean natural language processing.

A Study on the Installation of Groyne using Critical Movement Velocity and Limiting Tractive Force (이동한계유속과 한계소류력을 활용한 수제 설치에 관한 연구)

  • Kim, Yeong Sik;Park, Shang Ho;An, Ik Tae;Choo, Yeon Moon
    • Journal of Wetlands Research
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    • v.22 no.3
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    • pp.194-199
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    • 2020
  • Unlike in the past, the world is facing water shortages due to climate change and difficulties in simultaneously managing the risks of flooding. The Four Major Rivers project was carried out with the aim of realizing a powerful nation of water by managing water resources and fostering the water industry, and the construction period was relatively short compared to the unprecedented scale. Therefore, the prediction and analysis of how the river environment changes after the Four Major Rivers Project is insufficient. Currently, part of the construction section of the Four Major Rivers Project is caused by repeated erosion and sedimentation due to the effects of sandification caused by large dredging and flood-time reservoirs, and the head erosion of the tributaries occurs. In order to solve these problems, the riverbed maintenance work was installed, but it resulted in erosion of both sides of the river and the development of new approaches and techniques to keep the river bed stable, such as erosion and excessive sedimentation, is required. The water agent plays a role of securing a certain depth of water for the main stream by concentrating the flow so much in the center and preventing levee erosion by controlling the flow direction and flow velocity. In addition, Groyne products provide various ecological environments by forming a natural form of riverbeds by inducing local erosion and deposition in addition to the protection functions of the river bank and embankment. Therefore, after reviewing the method of determining the shape of the Groyne structure currently in use by utilizing the mobile limit flow rate and marginal reflux force, a new Critical Movement Velocity(${\bar{U}}_d$) and a new resistance coefficient formula considering the mathematical factors applicable to the actual domestic stream were developed and the measures applicable to Groyne installation were proposed.

Interface Reaction of Molten Converter Slag and Sintered CaO Pellet (용융 전로슬래그와 소결 CaO 펠렛 사이의 계면반응)

  • Kim Yaung-Hwan;Ko In-Yang
    • Resources Recycling
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    • v.13 no.1
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    • pp.47-53
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    • 2004
  • As a basic study of the re-using molten converter slag as an ordinary portland cement by conversion process, molten slag and sintered CaO pellet was reacted each other. The dissolution rate of the sintered CaO pellet into the molten slag was measured and the changes of the reaction layer was also investigated. The converter slag reagent-grade $SiO_2$ added was melted and hold for 30 minutes in MgO crucible between $1350∼1500 ^{\circ}C$. Then sintered CaO pellet heated at the same temperature was dipped into the molten slag and hold for 10∼30 min. After the reaction, the crucible was cooled in air and the specimen was cut off to the horizontal direction of the crucible. The dissolution rate of CaO pellet was measured by the change of the radius of sintered CaO pellet and the interface layer was observed by SEM/EDX and XRD. The dissolution rate of sintered CaO pellet contacted with the slag of basicity 1 was 9.8 $\mu\textrm{m}$/min at $1350^{\circ}C$ and increased to 18.0 $\mu\textrm{m}$/min at $1500^{\circ}C$. The rate was slightly decreased to 7.6 $\mu\textrm{m}$/min at $1350^{\circ}C$ and 15.0 $\mu\textrm{m}$/min at $V^{\circ}C$ in the slag of basicity 2. The dissolution rate of CaO in converter slag was followed to the rule of Arrhenius' temperature dependency, and the apparent activation energy of the dissolution of CaO was 36 kcal/mole. In case of the slag basicity of 1, the thickness of $C_2$S layer was 64-118 $\mu\textrm{m}$ and the thickness of $C_3$S was 28∼90 $\mu\textrm{m}$ for 10∼30 minutes at $1500^{\circ}C$. And the thickness of the $C_3$S layer was 90∼120 $\mu\textrm{m}$ at the same conditions in the slag basicity of 2.