• Title/Summary/Keyword: Systematic reduction study

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Performance Measurement Method for Efficient Value Engineering Study of Railroad Construction Project (철도건설사업의 효율적인 VE수행을 위한 성능측정기법)

  • Lim, Jong-Kwon;Park, Mi-Yun;Park, Heung-Min;Kim, Sung-Hun;Lee, Kwang-Kyun
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.2242-2249
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    • 2008
  • A severe problem in VE study of a project is to reduce value due to loss of performance, caused by focusing on cost reduction. Also a lack of understanding performance concept, no trial VE workshop as well as cost saving-based policy have not satisfied customer needs. A efficient VE job plan for especially large scale railroad construction project is proposed in this study. This study developed a more objective performance evaluation system for value engineering study of mega projects and suggested a systematic process of performance quantitative analysis for value improvement. The proposed performance measurement method would be very useful for better communication and consensus between decision makers and VE team.

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Reaction of Bis(diethylamino)aluminum Hydride in Tetrahydrofuran with Selected Organic Compounds Containing Representative Functional Groups

  • Jin Soon Cha;Oh Oun Kwon;Jong Mi Kim
    • Bulletin of the Korean Chemical Society
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    • v.15 no.2
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    • pp.132-138
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    • 1994
  • Bis(diethylamino)aluminum hydride was utilized in a systematic study of the approximate rates and stoichiometry of the reaction of excess reagent with 55 selected organic compounds containing representative functional groups under standardized conditions (THF, $0^{\circ}C$, reagent to compound=4 : 1) in order to define the characteristics of the reagent for selective reductions. The reducing action of BEAH was also compared with that of the parent aluminum hydride. The reducing action of the reagent is quite similar to that of aluminum hydride, but the reducing power is much weaker. Aldehydes and ketones were readily reduced in 1-3 h to the corresponding alcohols. However, unexpectedly, a ready involvement of the double bond in cinnamaldehyde was realized to afford hydrocinnamyl alcohol. The introduction of diethylamino group to the parent aluminum hydride appears not to be appreciably influential in stereoselectivity on the reduction of cyclic ketones. Both p-benzoquinone and anthraquinone utilized 2 equiv of hydride readily without evolution of hydrogen, proceeded cleanly to the 1,4-reduction products. Carboxylic acids and acid chlorides underwent reduction to alcohols slowly, whereas cyclic anhydrides utilized only 2 equiv of hydride slowly to the corresponding hydroxylacids. Especially, benzoic acid with a limiting amount of hydride was reduced to benzaldehyde in a yield of 80%. Esters and lactones were also readily reduced to alcohols. Epoxides examined all reacted slowly to give the ring-opened products. Primary and tertiary amides utilized 1 equiv of hydride fast and further hydride utilization was quite slow. The examination for possibility of achieving a partial reduction to aldehydes was also performed. Among them, benzamide and N,N-dimethylbenzamide gave ca, 90% yields of benzaldehyde. Both the nitriles examined were also slowly reduced to the amines. Unexpectedly, both aliphatic and aromatic nitro compounds proved to be relatively reactive to the reagent. On the other hand, azo- and azoxybenzenes were quite inert to BEAH. Cyclohexanone oxime liberated 1 equiv of hydrogen and utilized 1 equiv of hydride for reduction, corresponding to N-hydroxycyclohexylamine. Pyridine ring compounds were also slowly attacked. Disulfides were readily reduced with hydrogen evolution to the thiols, and dimethyl sulfoxide and diphenyl sulfone were also rapidly reduced to the sulfides.

Effects of Chuna Manual Therapy(CMT) on Rotator Cuff Disorder: A Systematic Review (회전근개 질환에 대한 추나 치료의 효과: 체계적 문헌 고찰)

  • Hong, Su-Min;Do, Ki-Won;Yoon, Kwang-Sik
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.16 no.1
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    • pp.1-11
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    • 2021
  • Objectives This study aimed to evaluate the efficacy of Chuna manual therapy(CMT) in the treatment of rotator cuff disorder. Methods We searched th following nine online databases without language restriction (MEDLINE/PubMed, Cochrane library, Ebscohost, CNKI, RISS, NDSL, KMBASE, and KISS) to identify randomized controlled trials (RCTs) that used CMT in the treatment of rotator cuff disorder. The methodological quality of each RCT was assessed using the Cochrane risk-of-bias tool. Results Four RCTs were included. in the meta-analysis. CMT resulted in a significant reduction in symptoms in these trials. However, there was a high risk of bias in the RCTs. Conclusions We reviewed RCTs that studied the effects of CMT for rotator cuff disorder. While the studies indicate that CMT has favorable effects on rotator cuff disorder. But the risk of bias for most of the studies was high. Therefore, high-quality studies are required to make further conclusions.

Manual Therapy for Failed Back Surgery Syndrome: A Systematic Review (척추 수술 실패 증후군에 대한 수기요법의 효과: 체계적 문헌 고찰)

  • HongRyoul Yoon;JiHong Jeong;SoonJoong Kim
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.17 no.2
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    • pp.1-15
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    • 2022
  • Objectives This study aimed to assess the efficacy and safety of manual therapy in patients with failed back surgery syndrome (FBSS). Methods We searched eight electronic databases from October 2022 and only selected randomized controlled trials (RCTs) reporting outcomes for manual therapy in FBSS patients. Included studies were analyzed qualitatively. Results A total of twelve RCTs were included and three studies were meta-analyzed. Manual therapy combined with exercise demonstrated more favorable outcomes in terms of pain reduction compared to exercise therapy only (P<0.01). Some studies reported that manual therapy resulted in low efficacy, while some studies reported that specific manual techniques have a significant effect in pain relief. We, therefore, conclude that several studies have a high risk of bias. Conclusions Findings suggest that manual therapy is a safe and non-invasive, promising option for managing FBSS. However, manual therapy is not the best option in all circumstances; thus, this should be selectively applied by a well-trained practitioner. Further studies such as well-designed, risk-controlled RCTs are required to gain stronger evidence.

Endoscopic diagnosis of gastric metastases from malignant melanoma: systematic review

  • Helena Campoli Reggiani;Ana Clara Aguiar Pongeluppi;Vitoria Froes Miraglia Martins Ferreira;Isadora Pinheiro Felix;Paulo Moacir de Oliveira Campoli
    • Clinical Endoscopy
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    • v.55 no.4
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    • pp.507-515
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    • 2022
  • Background/Aims: Metastases of malignant melanoma (MM) are rare and associated with poor prognosis. The objective of this study was to analyze the clinical and endoscopic characteristics of gastric metastases of MM by systematically reviewing cases and case series involving patients diagnosed using upper gastrointestinal endoscopy. Methods: The PubMed and LILACS databases were searched. Reports containing individual patient data were included. Outcomes such as clinical data, endoscopic findings, treatments, and survival were analyzed. Results: A total of 88 studies with individual data from 113 patients with gastric metastases of MM were included. The primary sites of MM were the skin (62%), eyes (10%), and mucous membranes (6%). Most patients (56%) had multiple metastases in the stomach, located predominantly in the gastric body (approximately 80%). The overall survival rate at 2 years was 4%. There was a significant reduction in the survival of patients with multiple gastric metastases compared to that of patients with single metastasis (hazard ratio, 0.459; 95% confidence interval, 0.235-0.895; p=0.022). Conclusions: Gastric metastases of MM have a poor prognosis, especially in patients with multiple implants in the stomach. Additional studies are needed to verify whether ocular and mucosal melanomas are associated with a higher risk of gastric metastases than that of cutaneous melanomas.

No evidence on the effectiveness of oral splints for the management of temporomandibular joint dysfunction pain in both short and long-term follow-up systematic reviews and meta-analysis studies

  • Fouda, Atef Abdel Hameed
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.46 no.2
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    • pp.87-98
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    • 2020
  • The aim of this study was to determine the efficacy of oral splints in reducing the intensity of pain in patients with temporomandibular joint dysfunction in both short and long-term treatment durations. Electronic databases, Cochrane Library, MEDLINE via PubMed, Web of Science, Egyptian Knowledge Bank, and EMBASE were searched for randomized controlled trials comparing different types of splints to non-occluding splints, behavioral therapy, pharmacotherapy, counseling, and no treatment. The risk of bias was assessed by using Cochrane risk of bias recommendations. Fixed and random effects were used to summarize the outcomes. The effect estimates were expressed as standardized mean differences (SMD) or risk ratios with a 95% confidence interval (CI). Subgroup analyses were carried out according to the treatment duration. Twenty-two studies met the inclusion criteria. A meta-analysis of short-term studies up to three months revealed no significant difference between the study groups. However, long-term studies exhibited a significant difference in pain reduction in favor of the control group. Total analysis revealed that the control group resulted in significant pain reduction (SMD 0.14, 95% CI 0.05-0.23, P=0.002, I2=0%). Oral splints are not effective in reducing pain intensity or improving function in patients with temporomandibular joint dysfunction.

Sorption behavior of slightly reduced, three-dimensionally macroporous graphene oxides for physical loading of oils and organic solvents

  • Park, Ho Seok;Kang, Sung Oong
    • Carbon letters
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    • v.18
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    • pp.24-29
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    • 2016
  • High pollutant-loading capacities (up to 319 times its own weight) are achieved by three-dimensional (3D) macroporous, slightly reduced graphene oxide (srGO) sorbents, which are prepared through ice-templating and consecutive thermal reduction. The reduction of the srGO is readily controlled by heating time under a mild condition (at 1 10−2 Torr and 200℃). The saturated sorption capacity of the hydrophilic srGO sorbent (thermally reduced for 1 h) could not be improved further even though the samples were reduced for 10 h to achieve the hydrophobic surface. The large meso- and macroporosity of the srGO sorbent, which is achieved by removing the residual water and the hydroxyl groups, is crucial for achieving the enhanced capacity. In particular, a systematic study on absorption parameters indicates that the open porosity of the 3D srGO sorbents significantly contributes to the physical loading of oils and organic solvents on the hydrophilic surface. Therefore, this study provides insight into the absorption behavior of highly macroporous graphene-based macrostructures and hence paves the way to development of promising next-generation sorbents for removal of oils and organic solvent pollutants.

A Study on Electrostatic Discharging in Ultrapure and Electrolyzed Waters Using Kelvin's Thunderstorm Effect (캘빈방전 효과를 이용한 초순수 및 전해이온수의 정전기 방전 연구)

  • Kim, Hyung-won;Jung, Youn-won;Choi, In-sik;Choi, Byung-sun;Choi, Donghyeon;Ryoo, Kun-kul
    • Journal of the Semiconductor & Display Technology
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    • v.21 no.1
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    • pp.5-11
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    • 2022
  • Despite the increasing importance of manufacturing and application R&D for ultrapure deionized water and electrolyzed ion water, various and systematic studies have not been conducted until now. In this study, the electrostatic discharge (ESD) behavior of electrolyzed ion water using a proton exchange membrane(PEM) was evaluated according to the type, flow rate, and bubble of electrolyzed ion water. In addition, by observing that Oxidation Reduction Potential (ORP) value returns to the unique value of electrolyzed ion water after electrostatic discharge, the possibility of two types of ions participating in electrostatic discharge ((H2O)n+ (assumed)) and ions for maintaining the characteristics of electrolyzed water could be inferred. In order to confirm the chemical structure and characteristics of the cations, in-depth research related to water molecular orbital energy or band gap should be followed.

The effect of aromatherapy on pain in individuals with diabetes: a systematic review and meta-analysis

  • Mi-Kyoung Cho;Mi Young Kim
    • Journal of Korean Biological Nursing Science
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    • v.26 no.2
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    • pp.71-82
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    • 2024
  • Purpose: This study systematically analyzed the impact of aromatherapy on pain in individuals with diabetes. Methods: A search was performed in seven electronic databases based on the PICO-SD (Population, Intervention, Comparison, Outcome, Study Design) framework. The population (P) of interest was individuals with diabetes, and the intervention (I) included aromatherapy targeting pain reduction. The comparison (C) consisted of control groups that received no intervention, another intervention, or usual care. The outcome (O) measured was pain. The quality of the selected literature was assessed using the Joanna Briggs Institute checklist. In MIX 2.0 Pro, the pooled overall effect of pain was calculated using Hedge's g and a random-effects model, and heterogeneity was calculated using the Q statistic and Higgin's I2 values. Meta-regression and exclusion sensitivity analyses were performed. Results: Five articles and seven studies were included, showing a significant pooled overall effect of aromatherapy on diabetes-related pain (Hedge's g = -1.83, 95% CI: -2.76 to -0.91). Meta-regression demonstrated that effectiveness in reducing pain was associated with studies conducted in West Asia, those with IRB approval, and those receiving funding. Additionally, interventions involving subjects under 60, lavender oil (vs. turpentine oil or blended oils), massage therapy (vs. topical application), fewer hours per session, and more repeated measurements (vs. pre/post measurements) were associated with pain reduction. Conclusion: Aromatherapy, especially with lavender oil, effectively manages diabetes-related pain. Short-duration massage application is also effective. A personalized selection of oil type and application method could optimize therapeutic outcomes for individuals with diabetes.

A Study on the Preceding Researches for the Safety Behavior in Construction (건설업 안전관리를 위한 행동적 연구 동향 분석)

  • Rhee, Simon Hang-Bok;Oh, Chi-Don;Choi, Jin-Woo
    • Journal of the Korea Safety Management & Science
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    • v.15 no.3
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    • pp.19-28
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    • 2013
  • While the reduction of industrial accidents has been stagnant, many researchers have been studying and focusing on safety behaviors including safety perception, attitude and safety culture as a new solution as well as a turning-point of this issue. However, we do not pay attention to those studies and researches in Korean construction. Therefore, this study is to introduce preceding researches and case studies in other countries and suggest a new direction to Korean construction. This study found out the current situation and problems in Korean construction studies after tracing the safety perception, attitude and safety culture in Korea and reviewing the background and trend of overseas studies and researches with regard to safety behaviors. Fundamental researches and systematic studies must be conducted in Korean construction with the reference and research data of this study.