• Title/Summary/Keyword: limited measurements

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Experimental study on structural integrity assessment of utility tunnels using coupled pulse-impact echo method (결합된 초음파-충격 반향 기법 기반의 일반 지하구 구조체의 건전도 평가에 관한 실험적 연구)

  • Jin Kim;Jeong-Uk Bang;Seungbo Shim;Gye-Chun Cho
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.25 no.6
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    • pp.479-493
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    • 2023
  • The need for safety management has arisen due to the increasing number of years of operated underground structures, such as tunnels and utility tunnels, and accidents caused by those aging infrastructures. However, in the case of privately managed underground utility ducts, there is a lack of detailed guidelines for facility safety and maintenance, resulting in inadequate safety management. Furthermore, the absence of basic design information and the limited space for safety assessments make applying currently used non-destructive testing methods challenging. Therefore, this study suggests non-destructive inspection methods using ultrasonic and impact-echo techniques to assess the quality of underground structures. Thickness, presence of rebars, depth of rebars, and the presence and depth of internal defects are assessed to provide fundamental data for the safety assessment of box-type general underground structures. To validate the proposed methodology, different conditions of concrete specimens are designed and cured to simulate actual field conditions. Applying ultrasonic and impact signals and collecting data through multi-channel accelerometers determine the thickness of the simulated specimens, the depth of embedded rebar, and the extent of defects. The predicted results are well agreed upon compared with actual measurements. The proposed methodology is expected to contribute to developing safety diagnostic methods applicable to general underground structures in practical field conditions.

A Fusion Sensor System for Efficient Road Surface Monitorinq on UGV (UGV에서 효율적인 노면 모니터링을 위한 퓨전 센서 시스템 )

  • Seonghwan Ryu;Seoyeon Kim;Jiwoo Shin;Taesik Kim;Jinman Jung
    • Smart Media Journal
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    • v.13 no.3
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    • pp.18-26
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    • 2024
  • Road surface monitoring is essential for maintaining road environment safety through managing risk factors like rutting and crack detection. Using autonomous driving-based UGVs with high-performance 2D laser sensors enables more precise measurements. However, the increased energy consumption of these sensors is limited by constrained battery capacity. In this paper, we propose a fusion sensor system for efficient surface monitoring with UGVs. The proposed system combines color information from cameras and depth information from line laser sensors to accurately detect surface displacement. Furthermore, a dynamic sampling algorithm is applied to control the scanning frequency of line laser sensors based on the detection status of monitoring targets using camera sensors, reducing unnecessary energy consumption. A power consumption model of the fusion sensor system analyzes its energy efficiency considering various crack distributions and sensor characteristics in different mission environments. Performance analysis demonstrates that setting the power consumption of the line laser sensor to twice that of the saving state when in the active state increases power consumption efficiency by 13.3% compared to fixed sampling under the condition of λ=10, µ=10.

Air Quality Monitoring in Residential Areas near Ports and Industrial Complexes in Busan (부산시 항만 및 산단 인근 주거지역 대기질 모니터링과 분기별 특성확인)

  • Hyunji Ju;Seungho Lee;Minjung Kim;Gabeen Lee;Young-Seoub Hong
    • Journal of Environmental Health Sciences
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    • v.50 no.3
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    • pp.181-190
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    • 2024
  • Background: Air pollutants have been reported to have harmful effects on human health. Busan is a vulnerable area in terms of air quality due to the installation of various industrial complexes, particularly the port industry. However there is limited research data on the ambient air quality of residential areas near ports and industrial complexes. Objectives: This study aimed to determine the quarterly levels of air pollutants near industrial complexes and ports and to identify trends and characteristics of air pollutant exceedances. Methods: Air measurements were conducted quarterly. The measured air pollutants included O3, SO2, CO, NO2, PM10, and PM2.5. PM10 and PM2.5 were measured using BAM-1020 equipment, while O3, SO2, CO, and NO2 were measured using AP-370 Series equipment. The quarterly concentration levels of air pollutants were determined, and the influence of precipitation and commuting hours on fine particulate matter was examined. Analysis of variance (ANOVA) was conducted to determine if there was significance between the concentrations of fine particulate matter during commuting hours and non-commuting hours. Results: The concentrations of air pollutants were generally higher in the first and second quarters. Furthermore, the concentrations of PM10 and PM2.5 tended to decrease continuously following consecutive rainfall, with concentrations at the end of rainfall periods lower than those observed at the beginning. The frequency of exceeding average concentrations of PM10 and PM2.5 was higher on weekdays. Moreover, the average concentrations of PM10 and PM2.5 during weekday commuting hours were higher compared to non-commuting hours. Conclusions: The concentrations of air pollutants in the survey area were found to be higher than the overall average in Busan. Based on this study, continuous air quality monitoring is necessary for residential areas near industrial complexes and ports. For further research, health biomonitoring of residents in these areas should be conducted to assess their exposure levels.

Effects of Aroma Neck and Shoulder Massage and Red LED irradiation on cutaneous microcirculation in the neck area (아로마 목·어깨 마사지와 Red LED 조사가 목 피부 미세혈류에 미치는 영향)

  • Yang Yang;Seunghee Bae
    • Journal of the Korean Applied Science and Technology
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    • v.41 no.2
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    • pp.393-405
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    • 2024
  • This study investigates the effects of aroma neck and shoulder massage and Red LED irradiation on cutaneous microcirculation in the neck area. In this study, 30 women aged 20 to 60 were randomly assigned to three experimental groups. Group A (n=10) received Red LED irradiation after aroma neck and shoulder massage, while Group B (n=10) rested for 15 minutes after aroma neck and shoulder massage. Group C (n=10) only received Red LED irradiation. The results showed significant main effects of time between the baseline and post-treatment measurements in Groups A and B (F = 29.883, p < 0.001, 𝜂2 = 0.624), however, the main effects of the groups were not significant (F = 0.202, p = 0.659, 𝜂2 = 0.011), but there was a significant interaction between group and time (F = 8.452, p = 0.001, 𝜂2 = 0.320). There were no significant statistical differences in cutaneous microcirculation in the neck area after treatment in Group C (p > 0.05, Cohen's d = 0.202). In conclusion, Red LED treatment demonstrates limited effects on cutaneous microcirculation in the neck area, differentiating with the results of Groups A and B. Specifically, the combined effect of aroma neck and shoulder massage and Red LED treatment in Group A was not significant.

A Study on the Factors affecting Korean Medical Students' Satisfaction with Education (한의대생의 교육 만족도에 대한 영향 요인 연구)

  • Yejin Han
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.3
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    • pp.253-258
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    • 2024
  • This study investigated Korean medical students' satisfaction with education and examined the factors that affect the satisfaction with education. Based on a total of 372 survey responses, we analyzed the satisfaction with education by sectors, differences in the satisfaction with education between groups, and variables affecting the satisfaction with education. The results showed that the satisfaction with curriculum, instructors, evaluation, environment and overall education were all between 'neutral' and 'satisfied.' In addition, there were significant differences in overall satisfaction by gender and dropout experience, and the variables that significantly influenced overall satisfaction were curriculum, evaluation, and environment. This study is significant in that it investigated Korean medical students' satisfaction with education through the sophisticated measurements in various sectors, and suggested specific improvement strategies to increase educational satisfaction. However, there is a limitation that the results cannot be generalized because the study was limited to students at one university, so it is necessary to expand the scope of the further research to represent the population. Furthermore, it is necessary to collect and analyze data from various aspects, such as collecting qualitative data through student interviews to complement the quantitative data, so as to fully understand learners' needs. It is hoped that this study will encourage theoretical and practical research for improving Korean medicine education.

A New Correction Method for Ship's Viscous Magnetization Effect on Shipboard Three-component Magnetic Data Using a Total Field Magnetometer (총자력계를 이용한 선상 삼성분 자기 데이터의 선박 점성 자화 효과에 대한 새로운 보정 방법 연구)

  • Hanjin Choe;Nobukazu Seama
    • Geophysics and Geophysical Exploration
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    • v.27 no.2
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    • pp.119-128
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    • 2024
  • Marine magnetic surveys provide a rapid and cost-effective method for pioneer geophysical survey for many purposes. Sea-surface magnetometers offer high accuracy but are limited to measuring the scalar total magnetic field and require dedicated cruise missions. Shipboard three-component magnetometers, on the other hand, can collect vector three components and applicable to any cruise missions. However, correcting for the ship's magnetic field, particularly viscous magnetization, still remains a challenge. This study proposes a new additional correction method for ship's viscous magnetization effect in vector data acquired by shipboard three-component magnetometer. This method utilizes magnetic data collected simultaneously with a sea-surface magnetometer providing total magnetic field measurements. Our method significantly reduces deviations between the two datasets, resulting in corrected vector anomalies with errors as low as 7-25 nT. These tiny errors are possibly caused by the vector magnetic anomaly and its related viscous magnetization. This method is expected to significantly improve the accuracy of shipborne magnetic surveys by providing corrected vector components. This will enhance magnetic interpretations and might be useful for understanding plate tectonics, geological structures, hydrothermal deposits, and more.

The Effect of Spiral Balance Taping on Postoperative Sequelae in Breast Cancer : Case study (스파이랄 발란스 테이핑이 유방암 환자의 수술 후 후유증에 미치는 영향 : 사례연구)

  • Su-Ji Kang;Dae-Hee Lee;Cheul Jang;Back-Vin Lim
    • Journal of The Korean Society of Integrative Medicine
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    • v.12 no.3
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    • pp.37-47
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    • 2024
  • Purpose : Cancer survivors often suffer from postoperative sequelae. the diagnosing and provision of manual therapy using spiral taping significantly improves the quality of life of cancer patients. The aim of this case study is to investigate the immediate effects of spiral taping on pain, range of motion (ROM), chemotherapy-induced peripheral neuropathy (CIPN), and lymphedema following breast cancer surgery. Methods : The taping techniques were performed as follows by spiral taping. The measurements were taken before, in the middle, and after taping using a mobile phone camera, tape measure, and a numerical rating score (NRS). The evaluation employed a single-group pre-post design based on a primitive experimental design. Results : Out of four patients, all four exhibited Reverse circle flow energy (RCFE), Passive cervical right (Rt) rotation test, anterior-posterior movement pattern, nerve type (+), cold energy (CE), sangcho acupuncture point, blood clot, hwal point. Comparing before and after treatment, almost all values were reduced to zero after treatment in terms of pain complaints. The lack of range of motion (ROM) caused by the shortened tissue after surgery did not increase. The range of motion (ROM) lost due to pain returned to normal. The circumference of lymphedema did not show a tendency. The symptoms of CIPN improved. Conclusion : There was a significant change in joint range of motion, with pain decreasing, but there were structural limitations in the tissue due to total resection, and the chemotherapy-induced peripheral neuropathy scale. It was effectively treated surgical site pain, axillary membrane syndrome-induced pain, and unexplained pain. While there was a treatment effect for lymphedema in the evaluation of circumference values, there was no significant change in circumference. There was a significant effect on chemotherapy-induced peripheral neuropathy, particularly in treating numbness in the feet, which is a side effect of TC anticancer drugs. This case study found that spiral balance taping provides a rapid therapeutic effect for most side effects in patients who have undergone total breast cancer resection. However, the generalization is limited due to the small sample size, and further research is needed to determine the extent to which the effects of one treatment are maintained.

A Review of Herbal Medicine Treatments on Aftereffects of Thyroidectomy (갑상선 절제술 후 후유증의 한약 치료에 대한 최신 임상 연구 동향)

  • Soo-duk Kim;Min-jo Seo;Su-na Park;Hye-ri Jo;So-hyeon Ryu;Geon-sik Kong;Yo-sup Choi
    • The Journal of Internal Korean Medicine
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    • v.45 no.4
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    • pp.615-634
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    • 2024
  • Objectives: This study summarizes the current trends and results in clinical studies on herbal medicine treatments after thyroidectomy. Methods: Studies published between 2019 and 2024 were searched for on the China National Knowledge Infrastructure (CNKI), PubMed, and Research Information Sharing Service (RISS). The studies were analyzed according to year, study design, characteristics of the patients, and traditional Chinese medicine (TCM) intervention. A meta-analysis was conducted and classified according to the outcome measurements, such as the total effective rate (TER), thyroid stimulating hormone (TSH), free T4 (FT4), self-rating depression scale (SDS), CD3+, CD4+, and CD8+. CD8+. Results: A total of 18 randomized controlled trials (RCTs) and 5 non-randomized controlled trials were reviewed. The most common herbal prescriptions were decoctions made from Yangyin Sanjie (Yangeumsangyeol-tang), Yiqi Sanjie (Ikgisangyeol-tang), Yiqi Yangyin Sanjie (Ikgiyangeumsangyeol-tang), Yiqi Yangyin (Ikgiyangeum-tang), and Huiyan Zhuyu (Hoeyeomchugeo-tang). The most frequently used herbs were Prunellae Spica, Scrophulariae Radix, and Astragali Radix. The meta-analysis found that the group using both herbal and Western medicine was benefited more than the group using Western medicine alone (RR: 1.28, 95% CI: 1.20-1.37, P<0.00001). The experimental group had higher TSH, CD3+, and CD4+ levels, while FT4, SDS, and CD8++ were lower. However, due to high study heterogeneity, the results were not statistically significant. Conclusion: Complications after thyroidectomy include hypothyroidism, hypoparathyroidism, and psychological aftereffects. Herbal and conventional treatments showed potential in improving hormone levels, immune function, and depression, but statistical significance was limited due to study variability. These results should be interpreted cautiously given the risk of bias in the trials.

Analyses of Synchronous Fluorescence Spectra of Dissolved Organic Matter for Tracing Upstream Pollution Sources in Rivers (상류 오염원 추적을 위한 용존 유기물질 Synchronous 형광스펙트럼 분석 연구)

  • Hur, Jin;Kim, Mi-Kyoung;Park, Sung-Won
    • Journal of Korean Society of Environmental Engineers
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    • v.29 no.3
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    • pp.317-324
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    • 2007
  • Fluorescence measurements of dissolved organic matter(DOM) have the superior advantages over other analysis tools for applying to water quality management. A preliminary study was conducted to test the feasibility of applying synchronous fluorescence measurements for tracing and monitoring pollution sources in a small stream located in an upstream area of the Sooyoung watershed in Busan. The water quality of the small stream is affected by leachate from sawdust pile and discharge of untreated sewage. The sampling sites included an upstream site, two pipes discharging untreated sewage, leachate from sawdust, and a downstream site. Of the five field samples, the leachate was distinguished from the other samples by a high peak at a lower wavelength range and a blunt peak at 350nm, suggesting that synchronous fluorescence can be used as a discrimination tool for monitoring the pollution. The efficacy of various indices derived from the spectral features to discriminate the pollution source was tested for well-defined mixture of the sawdust leachate and the upstream stream by comparing (1)the difference between measured values and those predicted based on mass balance and the characteristics of the two samples and (2)the linear correlations between index values and mass ratios of the sample mixtures. Of various discrimination indices selected, fluorescence intensities at 276 nm$({\Delta}\lambda=30nm)$and 347 nm$({\Delta}\lambda=60nm)$ were suggested as promising potential discrimination indices for the sawdust pollution source. Despite the limited number of samples and the study area, this study illustrates the evaluation process that should be followed to develop rapid, low-cost discrimination indices to monitor pollution sources based on end member mixing analyses.

The Effect of Information Service Quality on Customer Loyalty: A Customer Relationship Management Perspective (정보서비스품질이 고객로열티에 미치는 영향에 관한 연구: 고객관계관리 관점)

  • Kim, Hyung-Su;Gim, Seung-Ha;Kim, Young-Gul
    • Asia pacific journal of information systems
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    • v.18 no.1
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    • pp.1-23
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    • 2008
  • As managing customer relationship gets more important, companies are strengthening information service using multi-channels to their customers as a part of their customer relationship management (CRM) initiatives. It means companies are now accepting such information services not as simple information -delivering tools, but as strategic initiatives for acquiring and maintaining customer loyalty. In this paper, we attempt to validate whether or not such various information services would impact on organizational performance in terms of CRM strategy. More specifically, our research objective is to answer the next three questions: first, how to construct the instruments to measure not information quality but information service quality?; second, which attributes of information service quality can influence corporate image and customer loyalty?; finally, does each information service type have unique characteristics compared with others in terms of influencing corporate image and customer loyalty? With respect to providing answers to those questions, the previous studies had been limited in that those studies failed to consider the variety of types of information service or restricted the quality of information service to information quality. An appropriate research model answering the above questions should consider the fact that most companies are utilizing multi channels for their information services, and include the recent strategic information service such as customer online community. Moreover, since corporate information service could be regarded as a type of products or services delivered to customer, it is necessary to adopt the criteria for assessing customer's perceived value when to measure the quality of information service. Therefore, considering both multi-channels and multi-traits may enable us to tell the detailed causal routes showing which quality attributes of which information service would affect corporate image and customer loyalty. As information service channels, we include not only homepage and DM (direct mail), which are the most frequently applied information service channels, but also online community, which is getting more strategic importance in recent years. With respect to information service quality, we abstract information quality, convenience of information service, and timeliness of information service through a wide range of relevant literature reviews. As our dependant variables, we consider corporate image and customer loyalty that both of them are the critical determinants of organizational performance, and also attempt to grasp the relationship between the two constructs. We conducted a huge online survey at the homepage of one of representative dairy companies in Korea, and gathered 367 valid samples from 407 customers. The reliability and validity of our measurements were tested by using Cronbach's alpha coefficient and principal factor analysis respectively, and seven hypotheses were tested through performing correlation test and multiple regression analysis. The results from data analysis demonstrated that timeliness and convenience of homepage have positive effects on both corporate image and customer loyalty. In terms of DM, its' information quality was represented to influence both corporate image and customer loyalty, but we found its' convenience have a positive effect only on corporate image. With respect to online community, we found its timeliness contribute significantly both to corporate image and customer loyalty. Finally, as we expected, corporate image was revealed to provide a great influence to customer loyalty. This paper provides several academic and practical implications. Firstly, we think our research reinforces CRM literatures by developing the instruments for measuring information service quality. The previous relevant studies have mainly depended on the measurements of information quality or service quality which were developed independently. Secondly, the fact that we conducted our research in a real situation may enable academics and practitioners to understand the effects of information services more clearly. Finally, since our study involved three different types of information service which are most frequently applied in recent years, the results from our study might provide operational guidelines to the companies that are delivering their customers information by multi-channel. In other words, since we found that, in terms of customer loyalty, the key areas would be different from each other according to the types of information services, our analysis would help to make decisions such as selecting strengthening points or allocating resources by information service channels.