• Title/Summary/Keyword: strength improvement

Search Result 2,912, Processing Time 0.029 seconds

Improvement of High Permittivity Pads for Areas with Generally Low Signal Sensitivity at 7T MRI (7T MRI에서 일반적으로 신호 감도가 낮은 영역에 대한 고유전율 패드 개선)

  • Yong-Tae, Kim;Hyeon-Man, Baek
    • Journal of the Korean Society of Radiology
    • /
    • v.16 no.6
    • /
    • pp.761-769
    • /
    • 2022
  • Pads with high dielectric materials have been used in a variety of applications to locally improve the field sensitivity and homogeneity of RF pulses in clinical MRI studies. In this study, we aimed to improve such pads in consideration of the practical problems associated with the application of actual clinical images. A high permittivity pad to increase the attenuated B1 field strength was fabricated and tested in 7T MRI. Sim4Life simulation and experimental results show stronger and relatively uniform B1 near field. In order to improve the image quality in the whole cerebellum, known as a region with low sensitivity, a guide was made to reduce the mechanical change of the pad. In order to improve the wearing comfort, the pad was designed by dividing it into upper and lower parts. The facial pad showed an overall signal increase effect in areas such as the turbinate in the nasal cavity. Signal increase was expected in areas such as the frontal lobe and eyes, but the effect was either insignificant or it was difficult to see the effect in the imaging protocol. In conclusion, this paper showed a cerebellar-optimized pad with an improved nasal signal while maintaining its effectiveness.

A Study on Drainage Capacity of PBD Installed in Deep Soft Ground (대심도 연약지반에 적용되는 PBD의 통수능에 관한 연구)

  • Byun, Yo-Seph;Ahn, Byung-Je;Chun, Byung-Sik
    • Journal of the Korean Geotechnical Society
    • /
    • v.25 no.9
    • /
    • pp.67-76
    • /
    • 2009
  • The problems of bearing capacity, settlement and shear deformation occur when constructing a structure such as harbor, airport and bridge on soft ground of marine clay, silty clay or sandy soil. Various ground improvement methods are applied to obtain preceding settlement of soft ground and strength increase. In this study, to analyze the applicability of PBD method in deep soft ground, the compound drainage capacity test was operated in comparison with SD. As a result of the test, a minimum drainage capacity of drain material was estimated to be more than $10\;cm^3/sec$ at a more than $400\;kN/m^2$ and less than $5\;cm^3/sec$ at a more than $500\;kN/m^2$ confining pressure in case of single core PBD. In case of double core PBD, it was estimated to be more than $10\;cm^3/sec$ at a more than $500\;kN/m^2$ confining pressure.

Effect of Viscosity and Clogging on Grout Penetration Characteristics (점도 변화와 폐색 현상을 고려한 그라우트재의 침투 특성)

  • Kim, Jong-Sun;Choi, Yong-Ki;Park, Jong-Ho;Woo, Sang-Baik;Lee, In-Mo
    • Journal of the Korean Geotechnical Society
    • /
    • v.23 no.4
    • /
    • pp.5-13
    • /
    • 2007
  • Many construction projects adopt grouting technology to prevent the leakage of groundwater or to improve the shear strength of the ground. Recognition as a feasible field procedure dates back to 1925. Since then, developments and field use have increased rapidly. According to improvement of grout materials, theoretical study on grout penetration characteristics is demanded. Fluid of grout always tends to flow from higher hydraulic potential to lower one and the motion of grout is also a function of formation permeability. Viscosity of pout is changed by chemical action while grout moves through pores. Due to the increment of viscosity, permeability is decreased. Permeability is also reduced by grout particle deposits to the soil aggregates. In this paper, characteristics of new cement grout material that has been developed recently are studied: injectable volume of new grout material is tested in two different grain sizes of sands; and the method to calculate injectable volume of grout Is suggested with consideration of change in viscosity and clogging phenomena. The calculated values are compared with injection test results. Viscosity of new grout material is found to increase as an exponential function of time. And lumped parameter $\delta$ of new grout material to be used for assessing deposition characteristics is estimated by comparing deposit theory with injection test results considering different soil types and different injection pressures. Injection test results show that grout penetration rate is decreased by the increase of grout viscosity and clogging phenomena.

Evaluation of Lateral Flow in Soft Ground under Embankment (성토하부 연약지반의 측방유동 평가)

  • Hong, Won-Pyo;Cho, Sam-Deok;Lee, Jae-Ho;Lee, Kwang-Wu
    • Journal of the Korean Geotechnical Society
    • /
    • v.22 no.10
    • /
    • pp.93-100
    • /
    • 2006
  • The lateral soil movement in soft grounds undergoing improvement with application of vertical drains is analyzed on the basis of monitoring data at three fields, in which fifty six monitoring sites are located. Based on the investigations, the criterions are suggested to predict the lateral soil movement. In order to predict the lateral soil movement in the improved soft grounds by using the dimensionless parameter R suggested by Marche & Chapuis (1974), it is desirable that the maximum lateral displacement in the soft ground below the toe of embankment should be applied to calculate R instead of the lateral displacement at the toe of embankment. The lateral soil movement may increase rapidly, if the safety factor of slope is less than 1.4 in case of high ratio of H/B (Thickness of soft ground/Embankment width) such as 1.15 or is less than 1.2 in case of low ratio of H/B such as 0.05. Also, the graph suggested by Tschebotarioff (1973), which illustrates the relationship between the maximum height of embankments and the undrained shear strength of soft grounds, can be applied to the evaluation for the possibility of the lateral soil movement due to embankments on soft grounds.

Effect of convergence body stabilization exercise on the visual response speed and functional movement, balance, and vital capacity of High School Football Players. (융복합적 신체안정화운동이 고등학교 축구선수의 시각반응속도와 기능적 움직임, 균형 및 폐활량에 미치는 영향)

  • Seo, Yeon-Soon;Song, In-Young;Yoon, Jong-Hyuk
    • Journal of Digital Convergence
    • /
    • v.20 no.1
    • /
    • pp.191-202
    • /
    • 2022
  • The purpose of this study is to examine the effect of a 10-week body stability exercise program, which was conducted on 24 male football players. The result of the Visual Response Speed Test using BlazePod, showed a significant increase of the upper arms, left foot and right foot for 15 second in number of reactions and reaction time (p<0.001). As a result of evaluating whether or not 7 functional movements were improved in order to evaluate the functional movement screen, Hurdle Step (p=0.001) and Active Straight Leg Rise (p=0.022) movements were significantly improved. significantly improved. As a result of measuring the y-balance Test in order to evaluate the balance ability, composite score(p<0.001) of both sides was significantly improved. The result of evaluating vital capacity, which was conducted to evaluate mobility and muscle endurance, showed a significant improvement in Forced vital capacity(p<0.001) and Forced expiratory volume in 1.0(p=0.003). In conclusion, a 10-week BSE program intervention in high school period, which can most improve the technical fitness necessary for the game in power, agility, leg strength, leg stability, mobility, and muscle endurance, will improve overall technical fitness, prevent football players from being injured and enhance their performance.

A Study on the Suggestion of Community Facilities Model in Multi-Family Housing Complexes (공동주택단지 커뮤니티 시설 모델제안 연구)

  • Park, Hoon
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
    • /
    • v.8 no.7
    • /
    • pp.929-943
    • /
    • 2018
  • Together with the increase of public housing complex, the issues of community following residential environment under contemporary society has become an important issue and the collapse of traditional community has long been emerged as an important social issue. In order to facilitate communities within the public housing complex, various discussions have been continued, and for addressing such an issue under this study, the public housing complexes n Seoul, the capital region and other major cities have been surveyed and analyzed to draw following conclusion as the design-type study to propose a model of community facilities. It displays that there is certain limitation with respect to the diversity of programs when comparing the community facility standard defined under the public housing related laws and regulations. This is attributable to the fact that it is a limitation to satisfy the level of satisfaction for residents that expect the improvement in quality of leisure life, and the facility standard that is standardized around the physical facility environment has certain limitations to enhance the level of satisfaction for residents when the demand has been on the rise with respect to quality. For this fact, the approach in consideration of diversity for the facility standard has to be made in advance. As the utility of external space for the public housing is increased, it is reasonable to consider the plan to secure environment through the architectural factors, and it has the strength in enhancing the utility of internal and external space of the community facilities.

Effectiveness of NQ-E index-based individual nutrition counseling for community-care elderly: an intervention study on improving nutritional status, complex chronic diseases, and quality of life (커뮤니티케어 대상 노인의 NQ-E 지수 기반 개별영양상담 효과성: 복합만성질환과 삶의 질 개선에 관한 중재 연구)

  • Yoonjeong Choi;Jihyun Lee;Heesook Lim;Yoo Kyoung Park
    • Korean Journal of Community Nutrition
    • /
    • v.28 no.6
    • /
    • pp.480-494
    • /
    • 2023
  • Objectives: This study sought to assess the effectiveness of community-based nutrition counseling on improving nutritional status, managing complex chronic diseases, and enhancing the quality of life for elderly individuals with chronic conditions, particularly in older adults with high levels of food insecurity and multiple chronic illnesses. Methods: Thirty elderly subjects with diabetes and hypertension who were registered at local Senior Welfare Center received individualized nutrition counseling, based on their Nutrition Quotient for the Elderly (NQ-E) index. Over a 16-week period, they received tailored counseling and underwent various health and nutritional assessments. The final analysis included 28 participants after two dropped out. Data analysis was conducted using the SPSS v28.0. Results: The subjects were over 70, with multiple chronic diseases including diabetes and hypertension and predominantly female. After 16 weeks, significant improvements were observed in the subjects' grip strength, and HbA1c levels, as well as in their NQ-E scores, indicating improved dietary balance and diversity. There were no significant improvements in the 'Moderation' subdomain of the NQ-E index, suggesting that this aspect requires further attention in nutritional counseling. The subjects' nutritional risk scores (NSI) were also significantly decreased, indicating less nutritional risk. Lastly, as measured by the SF-36K, the subjects' quality of life showed significant improvement in several domains including physical role performance and social function. Conclusions: This study demonstrates that tailored nutrition counseling, based on the NQ-E index, can improve elderly health, manage chronic diseases, and enhance quality of life. This approach potentially broadens the scope of community nutritionists' roles within an aging society. However, additional research is necessary to evaluate these interventions' long-term effects and sustainability.

Small-cell Resource Partitioning Allocation for Machine-Type Communications in 5G HetNets (5G 이기종 네트워크 환경에서 머신타입통신을 위한 스몰셀 자원 분리 할당 방법)

  • Ilhak Ban;Se-Jin Kim
    • Journal of Internet Computing and Services
    • /
    • v.24 no.5
    • /
    • pp.1-7
    • /
    • 2023
  • This paper proposes a small cell resource partitioning allocation method to solve interference to machine type communication devices (MTCD) and improve performance in 5G heterogeneous networks (HetNet) where macro base station (MBS) and many small cell base stations (SBS) are overlaid. In the 5G HetNet, since various types of MTCDs generate data traffic, the load on the MBS increases. Therefore, in order to reduce the MBS load, a cell range expansion (CRE) method is applied in which a bias value is added to the received signal strength from the SBS and MTCDs satisfying the condition is connected to the SBS. More MTCDs connecting to the SBS through the CRE will reduce the load on the MBS, but performance of MTCDs will degrade due to interference, so a method to solve this problem is needed. The proposed small cell resource partitioning allocation method allocates resources with less interference from the MBS to mitigate interference of MTCDs newly added in the SBS with CRE, and improve the overall MTCD performace using separating resources according to the performance of existing MTCDs in the SBS. Through simulation results, the proposed small cell resource partitioning allocation method shows performance improvement of 21% and 126% in MTCDs capacity connected to MBS and SBS respectively, compared to the existing resource allocation methods.

A Study on the Reinforcement Effect of Low Flow Mortal Injection Method Using Field Test (현장시험을 이용한 저유동성 몰탈주입공법의 보강효과에 관한 연구)

  • Junyeong Jang;Gwangnam Lee;Daehyeon Kim
    • The Journal of Engineering Geology
    • /
    • v.33 no.4
    • /
    • pp.599-609
    • /
    • 2023
  • In the seismic retrofitting of harbor breakwaters in Korea, the recovery rate is often uncertain due to site conditions and site conditions, and problems continue to arise. Therefore, in this study, we analyzed the recovery rate and compressive strength of the improved material through drilling survey by grouting confirmation method after applying low-fluidity mortar injection method, and furthermore, we checked the elastic modulus by downhole test and tomography to confirm the reinforcement effect of soft ground after ground improvement. The experimental results showed that the average shear wave velocity of the ground increased from 229 m/s to 288 m/s in BH-1 and BH-3 boreholes to a depth of 28.0 m, and the average shear wave velocity of the ground to a depth of 30.0 m tended to increase from 224 m/s to 282 m/s in the downhole test. This is believed to be a result of the increased stiffness of the ground after reinforcement. The results of the tomographic survey showed that the Vs of the soft ground of the sample at Site 1 increased from 113 m/s to 214 m/s, and the Vs of the sample at Site 2 increased from 120 m/s to 224 m/s. This shows that the stiffness of the ground after seismic reinforcement is reinforced with hard soil, as the Vs value satisfies 180 m/s to 360 m/s in the classification of rock quality according to shear wave velocity.

A study of the multicomponent therapeutic recreation function intervention strategy by analysis on the operating condition of the cognitive rehabilitation program in dementia care center

  • Moon-Sook Lee;Byung-Jun Cho;Jae-Sik Yang
    • Journal of the Korea Society of Computer and Information
    • /
    • v.28 no.12
    • /
    • pp.155-166
    • /
    • 2023
  • This study was conducted with 50 elderly people each (5) participating in the cognitive rehabilitation treatment program at the Dementia Care Center in D City to derive the development direction and contents of a multidimensional therapeutic recreation program and a revitalization plan through analysis of the current status and actual conditions of the cognitive rehabilitation program at the Dementia Care Center. aperture) was selected, and 9 people were selected as the subject of expert group opinion collection. The collected data was SPSS ver. Using the 18.0 statistical program, descriptive statistics and the importance and priority of each component were analyzed by hierarchical structure analysis. First, unlike the needs of users, the cognitive rehabilitation support programs currently being provided are not sufficient and require considerable experience. It was found to be low, and the areas for improvement were the expansion of care and protection facilities and the development of various programs to meet the needs of users. Second, the importance and priority of each component of therapeutic recreation were categorized into 6 major categories: exercise therapy , middle category (16 items) behavior-centered approach to exercise therapy, small category (47 items) strength and brain gymnastics, and silver health gymnastics were the highest. This result shows that a multidimensional program plan that considers the priorities of each area must be made when developing a therapeutic recreation program.