• Title/Summary/Keyword: 허용한계

Search Result 540, Processing Time 0.03 seconds

Estimation of Permanent Displacement of Gravity Quay Wall Considering Failure Surface under Seismic Loading (지진 시 파괴면을 고려한 중력식 안벽의 영구변위 평가)

  • Han, Insuk;Ahn, Jae-Kwang;Park, Duhee;Kwon, Osoon
    • Journal of the Korean Geotechnical Society
    • /
    • v.35 no.4
    • /
    • pp.15-26
    • /
    • 2019
  • The stability of the gravity quay wall against earthquakes is evaluated on the basis of the allowable displacement of the wall. To estimate the displacement caused by external forces, empirical equations based on the Newmark sliding block method or numerical analysis are widely used. In numerical analysis, it is possible to analyze precisely a complicated site and structure, but difficult to set the appropriate parameters and environments; there are limitations in obtaining reliable results, depending on one's level of expertise. The Newmark method, with only seismic motions, is widely used because it is simpler than numerical simulations when estimating permanent displacement. However, the empirical equations do not have any parameters for the response characteristics and sliding block of the structure, and sliding blocks being assumed as rigid bodies does not consider the nonlinear behavior of the soil and interaction with the structure. Therefore, in order to evaluate the seismic stability of the gravity quay wall, a newly-developed empirical equation is needed to overcome the above-mentioned limitations. In this study, numerical simulations are performed to analyze the response characteristics of the backfill of the structure, and to propose an optimal method of calculating the active area. For this purpose, finite element analyses were performed to analyze the response characteristics, and stress-strain relationships for various seismic motions. As a result, the response characteristics, sliding block, and failure surface of the backfill vary depending on the input seismic motions.

Enrichment of POI information based on LBSNS (위치기반 소셜 네트워크 서비스(LBSNS)를 이용한 POI 정보 강화 방안)

  • Cho, Sung-Hwan;Ga, Chil-O;Huh, Yong
    • Journal of Cadastre & Land InformatiX
    • /
    • v.48 no.2
    • /
    • pp.109-119
    • /
    • 2018
  • Point of interest (POI) of the city is a special place that has what importance to the user. For example, it is such landmark, restaurants, museums, hotels, and theaters. Because of its role in the social and economic life of us, these have attracted a lot of interest in location-based applications such as social networks and online map. However, while it can easily be obtained through the Web, the basic information of POI such as geographic location, another effort is required to obtain detailed information such as Wi-Fi, accepting credit cards, opening hours, romper room and the assessment and evaluation of other users. To solve these problems, a new method for correcting position error is required to link location-based social network service (LBSNS) data and POIs. This paper attempts to propose a position error correction method of POI and LBSNS data to enrich POI information from the vast information that is accumulated in LBSNS. Through this study, we can overcome the limitation of individual POI information via the information fusion method of LBSNS and POI, and we have discovered the possibility to be able to provide additional information which users need. As a result, we expect to be able to collect a variety of POI information quickly.

A study on the debate on traditional technique for Architectural Heritage conservation - Focusing on the dispute over the application of traditional technique for the restoration of the Sungnyemun gate - (건축문화유산 보존과 관련된 전통기술 논의 고찰 - 숭례문 복구에 있어서의 전통기술 적용 논란을 중심으로 -)

  • Kang, Hyun
    • Korean Journal of Heritage: History & Science
    • /
    • v.47 no.3
    • /
    • pp.208-223
    • /
    • 2014
  • Since the recent restoration of the Sungnyemun gate (South gate of Seoul) which was burnt down in 2008, there were dispute about the application of traditional technique for the conservation of cultural heritage. In this research, the definition of traditional technique for cultural heritage conservation is thought and mentioned. In general, the understanding of traditional technique is based on the idea of 'tradition'. Tradition is not defined as a 'eternal doctrine existence', but a 'development of succession' and a 'living existence'. Thus 'traditional performance and craft as intangible cultural heritage' is defined as 'intangible' which also makes it difficult to define the 'original form/state' from 'the conservation of the original form' which is a major principle of cultural heritage. In case of Korea, if the 'traditional technique as intangible cultural heritage' is put into application to cultural heritage conservation, the unclear definition will cause many problems in the restoration/conservation site. This is because the site will apply this technique without any discussion of the range and limitation of 'traditional technique'. This means there will be the lack of discussion for the conservation of the cultural heritage which will not have a strict criteria for the allowable range of usage for the 'traditional material' using the vaguely defined 'traditional technique'. In this study, these application issues of the traditional technique were also considerecl, comparing the development of international wnservation principles. As a result, the conservation of 'traditional technique as intangible cultural heritage' is important, but the 'technique left inside the tangible cultural heritage' which is the 'material which is carrying the technique when it was firstly built' has more importance to preserve and need to be in the major considerations.

Establishment and Application of Subway Line Chain OD Using SSA (SSA를 이용한 지하철 노선 Chain OD 구축 및 활용)

  • Lee, Mee Young;Nam, Doohee
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.18 no.5
    • /
    • pp.100-111
    • /
    • 2019
  • The existing selected station analysis (SSA) method analyzes the link transfer mode data between origin and destination of individuals passing through stations from a microscopic standpoint. As such, existing SSA is insufficient as it uses integrated analysis using macroscopic data such as subway lines. This research builds a line chain OD based on path search of individual passenger's movement through the subway, and explores means to utilize the findings. First, a method is proposed that searches the traversed subway path from the linked passage modes that the passenger uses and applies the results to SSA line analysis. Compared to the existing SSA, this method provides for analysis of commonly conflicting features such as the line on which the station is passed, and the stations included on the line thanks to the presence of complete information of the individual passenger's traversed path. It also allows for integrated observation of the line chain OD that approaches a certain station. For enhanced understanding, Seoul Metro Line 9 is used as a case study to demonstrate the integrated formulation concept of line chain OD centered around a certain station as well as the macroscopic features of the traversed path that approaches stations included on the line.

A Study for Improved Design Criteria of Composite Pile Joint Location based on Case Analysis (사례 분석을 통한 복합말뚝 이음위치의 설계 기준식 개선 연구)

  • Hwang, Uiseong
    • Journal of the Korean GEO-environmental Society
    • /
    • v.20 no.3
    • /
    • pp.21-30
    • /
    • 2019
  • Composite pile, which is composed of the steel pipe pile in which the large horizontal force acts and the PHC pile in which the small horizontal force acts by a special connecting devices, is being commercialized as a base material for civil engineering structures. The core of such a composite pile can be said to be a design criterion for estimating the joint position and stability of the connection device between steel pipe pile and PHC pile. In Korea, there is no precise specification for the location of composite pile joints. In the LH Design Department (Korea Land & Housing Corporation, 2009), "Application of composite pile design and review of design book marking" was made with reference to Road Design Practice Volume 3 (Korea Expressway Corporation, 2001). this is used as a basis of the design of the composite pile. It can not be regarded as a section change of the composite pile, so it has a limitation in application. Therefore, In this study, we propose a design criterion for the location of the section of the composite pile (joint of steel pipe pile and PHC pile) and evaluate the stability and economical efficiency of it by using experimental method and analytical method. Analysis of composite pile design data installed in 79 domestic bridges abutment showed that the stresses, bending moments, and displacements acting on the pile body and connection of the pile were analyzed. Through the redesign process, it was confirmed that the stresses generated in the connecting device occur within the allowable stress values of the connecting device and the PHC pile. In conclusion, the design proposal of composite pile joint location through empirical case study in this study is an improved design method considering both stability and economical efficiency in designing composite pile.

The Directive Writing in the Works of Joël Pommerat and Jean-Claude Grumberg : "le politique" of Fiction (조엘 폼므라와 장-끌로드 그룸베르그의 작품에서 나타나는 연출적 글쓰기 : 픽션의 정치)

  • Ha, Hyung-Ju
    • The Journal of the Korea Contents Association
    • /
    • v.19 no.5
    • /
    • pp.163-177
    • /
    • 2019
  • This study is concerned with "fiction" as a new form of writing over the limits of the post-modernist theater/arts. Fiction is not something illusory that demands the audience's empathy but something that unveils form's disinterest in content. Thus, in this paper, I examine a fiction as the opposition of any representational norm and words' old mimesis. Rebutting the crisis of post-modern art and the end of images, philosopher Jacque $Ranci{\grave{e}}re$ mentions the possibility of appropriating similarity in an imitative way by twisting Platonic mimesis. The image of this similarity wanders alongside the loss of signification, unmasking the form's indifference to content. These wandering words represent their own truth "in a way fossils or grooved stones encapsulate histories" as hieroglyphics. This "fiction" as an alternative of post-modernist plays is not any confrontation of reality but the "movement of thinking" that allows the human spirit to play in a way of shaping "some substantiality." In this sense, I examines works by two French writers, $Jo{\ddot{e}}l$ Pommerat (1963~) and Jean-Claude Grumberg (1939~ ) who have carried out their writing practices of appropriating similarity that dissolves any simple "immediate reflection" for non-intermediate relations between the producing and the produced. Their writing is a cross of literary creation and "le politique" as a new aesthetic practice of writing and reveals the movement of thinking, departing from the preexisting concept of fiction.

Color Distribution Analysis of Maxillary Primary Central Incisors using a Spectrophotometer (분광광도계를 이용한 상악 유중절치의 부위에 따른 색조 분포 연구)

  • Yi, Seoksoon;Jang, Jihye;Lee, Daewoo;Yang, Yeonmi;Kim, Jaegon
    • Journal of the korean academy of Pediatric Dentistry
    • /
    • v.46 no.1
    • /
    • pp.93-100
    • /
    • 2019
  • The objective of this study was to analyze the color distribution of the maxillary primary central incisors and the relationship between the color of each tooth region by dividing tooth into incisal, middle and cervical region using a spectrophotometer. The subjects were 105 sound maxillary primary central incisors from 3 to 6 years old children. Color measurements were performed by one dentist using same protocol. CIE $L^*$, $a^*$, $b^*$, $C^*$, $h^*$ data and the best matched shades with coverage error were obtained for each region and whole labial surface. There was a significant difference in CIE $L^*$, $a^*$, $b^*$ according to regions and the difference in color between each region was more than the clinical acceptance. By correlating the relationship between the color of each region with $L^*$, $a^*$, $b^*$ values, it is possible to extrapolate the color of other region with one color or to be used as data for making restorative materials and prostheses that are more aesthetically pleasing for primary teeth.

A Scope of Work of Radiological Technologists for Ultrasound Examinations (초음파검사에 대한 방사선사 업무범위의 법적 고찰)

  • Lim, Chang Seon;Jin, Gye Hwan
    • Journal of the Korean Society of Radiology
    • /
    • v.15 no.4
    • /
    • pp.481-490
    • /
    • 2021
  • There is no qualification system for sonographers in Korea. But the MEDICAL SERVICE TECHNOLOGISTS, ETC. ACT stipulates that radiological technologists can handle ultrasound equipment. However, there is controversy about the scope of the work allowed for radiological technologists to perform ultrasound examinations. Accordingly, the authoritative interpretation of the Ministry of Health and Welfare of Korea, the adjudication of administrative judgment, and the judgment of the courts were analyzed. As a result, the authoritative interpretation expresses that when a radiological technologist performs an ultrasound examination, a diagnosis and specific guidance should be made in real time while the doctor simultaneously watches the radiological technologist's images. In the adjudication of administrative judgment, it was decided that the handling of ultrasound-related equipment was the work of the radiological technologist. The court ruled that it was illegal for a radiological technologist to make a medical judgment on ultrasound examination. In the United States, Canada, etc., the sonographer independently conducts ultrasound examination according to the doctor's prescription, prepares a summary of what they saw and this is passed on to the doctor. Therefore, in Korea, there is a need for institutional improvement so that radiological technologists can perform ultrasound examinations according to doctors' prescriptions without real-time guidance.

A review on the previously performed hydraulic experiments of bank protection materials (기 수행된 호안재료 수리 검토 실험에 관한 고찰)

  • Chanjoo Lee;Myeonghwan Kim;Sungjung Kim;Muyoung Na
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2023.05a
    • /
    • pp.297-297
    • /
    • 2023
  • 최근 친수성, 경관, 생태계 보전 등을 위해 다양한 호안블록의 시공이 이루어지고 있어 호안블록의 수리적 안정성에 관한 관심이 증가하고 있다. 이러한 배경 하에 한국건설기술연구원 안동하천실험센터(이하 센터)에서는 2019년부터 실규모 수로를 이용하여 여러 건의 호안블록 실규모 수리검토 실험을 실시한 바 있다. 본 연구는 그간의 실험 결과를 종합적으로 고찰하고 수리 검토 실험의 현황과 한계점, 그리고 개선 방향을 제언하는데 그 목적이 있다. A1 수로(급경사수로, 하상경사 1/70)에서는 7건(21회), B1 수로(고유속수로, 하상경사 1/7)에서는 2건(6회)의 실험이 수행되었다. A1 수로 실험의 유량-소류력 관계는 1.0 m3/s에서 약 20 N/m2이며, 1.0 m3/s 증가당 약 11 N/m2이 증가하는 관계를 나타낸다. 7건의 실험 결과 30분 이상 지속된 최대 실험 유량은 6~7 m3/s 정도이며, 이는 A1 최대 공급 유량의 75 % 정도로서 안정적인 수준이라고 판단된다. 이 때의 최대 소류력은 75 N/m2 정도로 나타났다. B1 수로는 5 m/s 이상의 고유속 흐름을 발생시킬 수있으며, 2건의 실험 결과 0.5 m3/s에서 약 100 N/m2, 최대 4.5 m3/s에서 330 N/m2까지 소류력을 제공하여 실험을 수행한 바 있다. 따라서 A1, B1 수로를 통해 제공할 수 있는 소류력 범위는 10~330 N/m2이지만, 75~100 N/m2는 실험에서 제공된 바 없었다. 한편, 토양유실의 경우 수준측량에 의해 측정되는데, 대부분의 실험에서 Clopper의 토양손실 지수(1.27 cm) 미만의 결과가 발생하였다. 이는 시험체에 따라 여건이 다르기는 하지만, 수리 검토 실험시 3회 실험을 기본으로 하고 있고 호안재료의 침식이 기준 이하로 유지되면서 최대한의 성능을 발휘할 수 있는 소류력 조건을 얻으려는 실험 목적에 부합하도록 조절된 것으로 볼 수 있다. 이러한 실험 결과를 토대로 고려해볼 수 있는 개선 방향은 다음과 같다. 강성 재료가 아닌 연성 또는 친환경적 호안재료의 허용 소류력 범위를 보다 넓게 평가하기 위해 A1 수로가 제공하는 최대 소류력을 높일 필요가 있다. 이를 위해 기본 3회의 실험 외에 추가로 호안블록이 파괴되거나 토양유실 임계치를 초과할 수 있는 실험을 수행함으로써 각 제품의 한계 성능을 평가하는 것이 필요할 것으로 보인다.

  • PDF

Levels of sulfonamides for animals in food (식품 중 설폰아마이드계 동물용의약품의 잔류실태)

  • Jeong, Jiyoon;Hong, Mooki;Choi, Dongmi
    • Analytical Science and Technology
    • /
    • v.20 no.1
    • /
    • pp.84-90
    • /
    • 2007
  • To determine levels of 11 sulfonamides for animals in food, simultaneously, a selective method of high performance liquid chromatography with UV detector has been applied. The targets were sulfachlorpyridazine (SCP), sulfadiazine (SDZ), sulfadimethoxine (SDM), sulfisoxazole (SSX), sulfamerazine (SMZ), sulfamethazine (SMT), sulfamethoxazole (SMX), sulfamethoxypyridazine (SMP), sulfamonomethoxine (SMM), sulfaquinoxaline (SQX) and sulfathiazole (STZ). Food samples were beef, pork, chicken, milk and whole egg that were collected at the main 6 cities in Korea as Seoul, Busan, Daejon, Incheon, Mokpo and Gangneung. After homogenizing food samples with sodium phosphate solution and acetonitrile, it was extracted with n-hexane. The mobile phase gradient was a mixture of 5 mM potassium phosphate (pH 3.25) and methanol with a gradient ratio from 100:0 to 30:70. The UV wavelength was 270 nm. The overall recoveries were ranged from 75% to 95% and the limit of detection was minimum 0.004 mg/kg for SMT, and 0.007 mg/kg for STZ at signal/noise > 3, respectively. As results, sulfonamide drugs were not detected in most of the selected food samples, however, sulfamonomethoxine was detected in meat. The determined level of sulfamonomethoxine were 0.03 and 0.06 mg/kg for beef that were below the MRLs.