• Title/Summary/Keyword: period-k component

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A Study on the Interface Micromotions of Cementless Artificial Hip Replacement by Three-Dimensional FEM (무시멘트형 인공고관절 대치술후 초기의 경계면 미세운동의 3차원 FEM 연구)

  • Kim, S.K.;Chae, S.W.;Choi, H.Y.
    • Proceedings of the KOSOMBE Conference
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    • v.1994 no.12
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    • pp.71-74
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    • 1994
  • In cementless total hip arthroplasty(THA), an initial stability of the femoral component is mandatory to achieve bony ingrowth and secondary long term fixation. Bone ingrowth depends strongly on relative micromotion and stress distributions at the interface. Primary stability of the femoral component can be obtained by minimizing the magnitude of relative micromotions at bone-prosthesis interface, Hence an accurate evaluation of interface behavior and stress/strain fields in the bone implant system may be relevant for better understanding of clinical situations and improving THA design. However, complete evaluation of load transfer in the bone remains difficult to assess experimentally, Hence, recently finite element method (FEM) was introduced in orthopaedic research field to fill the gap due to its unique capacity to evaluate stress in structure of complex shape, loading and material behavior. The authors developed the 3-dimensional numerical finite element model which is composed of totally 1179 elements off and 8 node blick. We also analyzed the micromotions at the bone-stem interface and mechanical behavior of existing bone prosthesis for a loading condition simulating the single leg stance. The result indicates that the values of relative motion for this well fit Multilock stem were $150{\mu}m$ in maximum, $82{\mu}m$ in minimum, and the largest relative motion developed in medial region of proximal femur with anterior-posterior direction. The proximal region of the bone was much larger in motion than the distal region and the stress pattern shows high stress concentration on the cortex near the tip of the stem. These findings indicates that the loading in the proximal femoral bone in the early postoperative situation can produce micromotions on the interface and clinically cementless TEA patient should not be allowed weight bearing strictly early in the postoperative period.

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Scent Analysis Using an Electronic Nose and Flowering Period of Potted Diploid and Tetraploid Cymbidium (심비디움 2배체, 4배체의 분화수명 조사 및 전자코를 이용한 향기패턴분석)

  • Hwang, Sook-Hyun;Kim, Mi-Seon;Park, Pue-Hee;Park, So-Young
    • Horticultural Science & Technology
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    • v.34 no.1
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    • pp.163-171
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    • 2016
  • We investigated the intensity and pattern of the scent produced by diploid and tetraploid Cymbidium flowers, using an electronic nose with 6 metal oxide sensors (MOS). The MOS responses were evaluated by principal component analysis, discriminant function analysis, and sensor data. These analyses revealed that tetraploid flowers had a stronger scent than diploid flowers in Cymbidium Golden Elf 'Sundust'. Furthermore, among the different flower parts-column, lip, and petals-the column produced the strongest scent. There was no significant difference between the flowering periods of diploid and tetraploid potted Cymbidium Golden Elf 'Sundust' and Cymbidium Elma 'Orient Toyo' grown in a greenhouse. Moreover, there were no significant differences between the number of flowers per flower stem and the length of flower stems on the diploid and tetraploid plants of these two Cymbidium cultivars. This study provides potentially useful information for the breeding of polyploidy Cymbidium in the floriculture industry.

Estimation of Applicability of Empirical Design Procedure for Predicting Seismic Response of Buried Gas Pipelines through 3D Time-history Analysis (3차원 시간이력해석을 통한 매설가스배관 종방향 지진응답 예측을 위한 경험적 설계법의 적용성 평가)

  • Kwak, Hyungjoo;Park, Duhee;Lee, Jangguen;Kang, Jaemo
    • Journal of the Korean Geotechnical Society
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    • v.31 no.9
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    • pp.53-68
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    • 2015
  • Longitudinal strain is an important component of seismic design for buried pipelines. A design procedure which determines the wavelength from site natural period and shear wave velocity of the soil layer and closed-form solutions of pipelines under a harmonic motion is typically used in design. However, the applicability of the procedure has not yet been thoroughly investigated. In this paper, displacement-time histories extracted from 1D site response analyses are used in 3D shell-spring model to accurately predict the response of pipelines. The results are closely compared to those from the design procedure. The area of interest is East Siberia. Performing a site response analysis to determine site specific displacement time history is highlighted. The site natural period may be used to predict the predominant period of the acceleration time history, but cannot be used to estimate the predominant period of the displacement time history. If an accurate estimate of the predominant period of the displacement time history is provided, it is demonstrated that the design equation can be successfully used to predict the response of pipelines.

Types and Historical Transition of Korean Traditional Seokgasan (한국 전통 석가산의 유형과 역사적 변천)

  • Yoon, Young-Jo;Yoon, Young-Hwal
    • Journal of the Korean Institute of Landscape Architecture
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    • v.38 no.3
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    • pp.83-97
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    • 2010
  • Seokgasan which is artificial rock mountain had been developed into one of the axes of traditional rock landscape of Goryo period and Joseon period as the central component of Korean traditional landscaping, but the legacy was cut off at the present. In the middle of the Goryo period, the Seokgasan made by piling rocks which were started from replicating miniature landscape has been developed into presenting the symbol and Seokgasan so it faced the new transition period of traditional rock garden culture. Seokgasan so it as small knoll, the Korean traditional Seokgasan was made differently the the surrounding landscape with big Seokgasan in China which overwhelms so it harmonize the surrounding landscape to build Korean style of the Seokgasan. This study is the objective investigation based on the old literature and the field remains, so it aims to so it comprehend the type of Seokgasan and developmental forms. At the result of investigation, 5 types of Seokgasan such as rocks piling on a pond, piling rocks, rocks in a pond, rocks on a ground, rock in a pot etc. has been developing in addition to the rocks which the oddly shaped rock is piled up as the basic framework. Among those, the piling rocks on a pond of Seokgasan which means water flows in Seokgasan is the representative Seokgasan which has been continued since the middle of the Goryo period until the end of the Joseon period. This study is expected to be the foundation which will succeed to legacy of Seokgasan tradition which was cut off and to develop by recovering historical landscaping value and identity of Seokgasan.

A Study on Constructability Estimation of Multi-component High Fluidity Concrete based on Mock-up Test (모의실험체에 의한 다성분계 고유동 콘크리트의 시공성능 평가에 관한 연구)

  • Kwon, Ki-Joo;Noh, Jea-Myoung
    • Journal of the Korea Institute of Building Construction
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    • v.10 no.4
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    • pp.75-82
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    • 2010
  • As structures become larger, taller, and more diverse, a high degree of technology and expertise are required in the construction industry. However, it has been becoming difficult to construct under severe conditions and to fulfill the high performance needs of structures due to a lack of skilled construction engineers. To compensate for these weak points, high-performance concrete and performance specifications have been developed. The application of reliable high-fluidity concrete, which is one of these efforts, is expected to be effective in terms of overcoming severe conditions, reducing the number of workers required, and shortening the construction period. In order to apply high fluidity concrete in the field, practical mock-up tests were carried out to estimate whether self-compaction concrete could satisfy constructability needs. From the results, it was verified that the multi-component high fluidity concrete has excellent flowability in practical structures. In addition, it was shown that the temperature distribution in the concrete due to hydration heat is satisfactory. As a result, it is judged that multi-component high fluidity concrete can be utilized as an effective building material for various structures, including structures related to the electric power industry.

Mantle Source Lithologies of Late Cenozoic Basaltic Rocks and Two Varieties of Enriched Mantle in the Korean Peninsula (한반도 신생대 후기 현무암의 근원 맨틀 암상과 두 종류의 부화 맨틀)

  • Choi, Sung Hi
    • Korean Journal of Mineralogy and Petrology
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    • v.35 no.3
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    • pp.183-197
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    • 2022
  • Geochemical data, including Sr-Nd-Pb-Mg-Zn isotopes, reported on the late Cenozoic intraplate basaltic rocks in the Korean Peninsula (Mt. Baekdu, Jeongok, Baengnyeong Island, Pyeongtaek, Asan, Ganseong, Ulleung Island, Dok Island, and Jeju Island) are summarized to constrain their mantle source lithologies, and the nature of mantle end-members required. In the Sr-Nd isotope correlation diagram, Jeju basalts plot in the field of EM2-type oceanic island basalts (OIB), while the other basalts fall in the EM1-type OIB field. In Pb-Pb isotope space, Jeju basalts show a mixing array between Indian MORB and EM2 component, whereas the other basalts display an array with EM1 component. The Korean basalts were derived from a hybrid source of garnet lherzolite and recycled stagnant slab materials (eclogite/pyroxenite, pelagic sediments, carbonates) in the mantle transition zone. The EM1 component could be ancient (~2.0 Ga) K-hollandite-bearing pelagic sediments that were isolated for a long period in the mantle transition zone due to their neutral buoyancy. The EM2 component might have been relatively young (probably Pacific slab) and recently recycled clay-rich pelagic sediments. Eclogite and carbonates are unlikely to account for the EM components, but they are common in the mantle source of the Korean basalts.

A Study on Fisheries Business Trends during the Period of Japanese Colonial Rule in Tongyeong based on Fisheries Status, Catches and Issues (통영지역의 일제강점기 수산관련 주요 동향에 대한 분석 -어업현황, 어획고, 주요 이슈 등을 중심으로-)

  • Lee, Dong-Ho
    • The Journal of Fisheries Business Administration
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    • v.46 no.2
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    • pp.75-92
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    • 2015
  • Generally, the outcomes of the historical study in some domain would be a most fundamental and basic reference for understanding the essential and core component of them. Specially in case of social science, the importance of historical research much more emphasized that would be divided into independent academic field. In Korean history including fisheries business and industry, the most remarkable historic event would be the period of Japanese colonial rule that one of the most obstacle should overcome. Though the fisheries business and industry of Korea have considerable own history, the research and study of that not so much have been performed or investigated including the period of Japanese colonial rule. Most of the existing research of fisheries history have merely focused on partial topics like 'Fishermen's Association', 'Fisheries Industry Despoliation'. And the historical study of fisheries business and industry's overall status and trend in local area except Pusan also not enough. The aims of this study are exploring the fisheries trends and status during the period of Japanese colonial rule in Tongyeong and finding out the overall major fisheries business issues that would be a better understanding the Korean fisheries industry. Achieving that Objectives, over 800 articles of media, the Japanese government-general of Korea, and other historical data were gathered, refined and analyzed. This paper focused on of major fisheries topics and issues that including overall fisheries status, trends, fisheries catches, local fisheries cooperatives and fisheries exhibition during the period of Japanese colonial rule in Tongyeong. The result of this study shows that the status of fisheries in Korea had been deteriorated for exploitation of Japanese imperialism and Japanese fisheries capitalist during that period. Though the level of Tongyeong in fisheries was very high in terms of catches ratio and population of fisherman, the distribution networks of fishermen's association was not good enough. And the Tongyeong fisheries exhibition in 1922 has positive aspects for considering both composition of organization and educational activity. Even though the results and findings would be a helpful guidelines for understanding the fisheries business trends and status under the rule of Japanese imperialism, more research and study of that should be accomplished.

A Study on Temporal Variations of Geomagnetic Transfer Functions and Polarization Values Obtained at Cheongyang Geomagnetic Observatory (청양 지자기관측소에서 획득된 지자기전달함수와 분극값의 시간변동성에 대한 연구)

  • Yang, Jun-Mo;Lee, Heui-Soon;Oh, Seok-Hoon
    • Journal of the Korean earth science society
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    • v.30 no.7
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    • pp.824-833
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    • 2009
  • We analyzed a total of six months of geomagnetic data obtained at Cheonyang observatory, which is operated by Korean Meteorological Administration, to monitor earthquake precursors. Geomagnetic transfer functions (GTFs) and polarization values, which reflect the time-variations of the resistivity of subsurface, were estimated from 3-component geomagnetic data. The time-variant fluctuations were compared with the earthquake events occurred in the same period. Now that the daily GTFs show fairly irregular variations, we can not identify any correlation with the already occurred earthquakes and Kp index. On the other hand, we detect clear increases of the Ultra-Low-Frequency (ULF) band polarization values before the earthquakes, but the similar features are also observed even though the earthquake did not occur. This result may indicate that these time-variations are not just due to the earthquake precursor. For further understanding about these results, we need to investigate the relationship between the previous earthquake events and the geomagnetic data of other observatories.

Paleomagnetic Study of the Lower Ordovician Formations in the North Eastern Okcheon Zone (옥천대 북동부에 분포하는 하부 고생대층에 대한 고지자기 연구)

  • Min, Kyung Duck;Lee, Youn Soo;Hwang, Suk Yeon
    • Economic and Environmental Geology
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    • v.26 no.3
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    • pp.395-401
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    • 1993
  • Lower Ordovician rock samples were collected from 23 sites located at the Okcheon non-metamorphic zone, near Taeback and Yeongweol areas, southern part of the Korean Peninsula. A characteristic magnetic component was obtained from four sites. This stable direction ($Dm=-19.4^{\circ}$, $Im=24.1^{\circ}$) which is carried by hematite of very high temperature $679^{\circ}C$), successfully pass both of reversal test and paleopole reliability test, and is regarded as a primary direction. The remagnetized components can be divided into three on the basis of their characteristic directions and magnetic minerals. The first which is carried by hematite, magnetite and pyrrhotite, is widely found at the whole sites. It shows syn- or post-tectonic remagnetization according to strongly negative fold test and distribution between Mesozoic and present field directions. The second, in situ, is distinguishable from the present field direction. After bedding correction, it is identical to Late Triassic to Early Jurassic direction. Its magnetic carrier is considered to be a single component hematite, which may be acquired by pre-tectonic CRM in the Okcheon orogenic zone. The third, which is carried by magnetite and hematite, is characterized by stable reversed direction. These minerals may be acquired by the thermal or chemical process in unknown period. Paleopole position is $169.2^{\circ}E$ in longitude and $59.9^{\circ}S$ in latitude, which indicates that the study area was located at $12.6^{\circ}S$ in paleo-latitude and belonged to northern end of the Gondwana in Early Ordovician.

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Exploring Chemotherapy-Induced Toxicities through Multivariate Projection of Risk Factors: Prediction of Nausea and Vomiting

  • Yap, Kevin Yi-Lwern;Low, Xiu Hui;Chan, Alexandre
    • Toxicological Research
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    • v.28 no.2
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    • pp.81-91
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    • 2012
  • Many risk factors exist for chemotherapy-induced nausea and vomiting (CINV). This study utilized a multivariate projection technique to identify which risk factors were predictive of CINV in clinical practice. A single-centre, prospective, observational study was conducted from January 2007~July 2010 in Singapore. Patients were on highly (HECs) and moderately emetogenic chemotherapies with/without radiotherapy. Patient demographics and CINV risk factors were documented. Daily recording of CINV events was done using a standardized diary. Principal component (PC) analysis was performed to identify which risk factors could differentiate patients with and without CINV. A total of 710 patients were recruited. Majority were females (67%) and Chinese (84%). Five risk factors were potential CINV predictors: histories of alcohol drinking, chemotherapy-induced nausea, chemotherapy-induced vomiting, fatigue and gender. Period (ex-/current drinkers) and frequency of drinking (social/chronic drinkers) differentiated the CINV endpoints in patients on HECs and anthracycline-based, and XELOX regimens, respectively. Fatigue interference and severity were predictive of CINV in anthracycline-based populations, while the former was predictive in HEC and XELOX populations. PC analysis is a potential technique in analyzing clinical population data, and can provide clinicians with an insight as to what predictors to look out for in the clinical assessment of CINV. We hope that our results will increase the awareness among clinician-scientists regarding the usefulness of this technique in the analysis of clinical data, so that appropriate preventive measures can be taken to improve patients' quality of life.