• Title/Summary/Keyword: Mass changes

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Temporal Characteristics of Volatile Organic Compounds in Newly-Constructed Residential Buildings: Concentration and Source

  • Shin, Seung-Ho;Jo, Wan-Kuen
    • Environmental Engineering Research
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    • v.18 no.3
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    • pp.169-176
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    • 2013
  • The present study was designed to examine the concentrations, emission rates, and source characteristics of a variety of volatile organic compounds (VOCs) in 30 newly-constructed apartment buildings by measuring indoor and outdoor VOC concentrations over a 2-year period. For comparison, seven villa-type houses were also surveyed for indoor and outdoor VOC concentrations over a 3-month period. Indoor and outdoor air samples were collected on Tenax-TA adsorbent and analyzed using a gas chromatograph (GC)/mass spectrometer system or a GC/flame ionization detector system coupled to a thermal desorption system. The long-term change in indoor VOC concentrations depended on the type of VOCs. Generally, aromatic (except for naphthalene), aliphatic, and terpene compounds exhibited a gradual deceasing trend over the 2-year follow-up period. However, the indoor concentrations of the six halogenated VOCs did not significantly vary with time changes. Similar to these halogenated VOCs, the indoor naphthalene concentrations did not vary significantly with time changes over the 2-year period. Unlike the halogenated VOCs, the indoor naphthalene concentrations were much higher than the outdoor concentrations. The indoor concentrations of aliphatic and aromatic compounds were higher for the villa-type houses when compared to those of apartment buildings. In addition, four source groups (floor coverings and interior painting, household products, wood paneling and furniture, moth repellents) and three source groups (floor coverings and interior painting, household products, and moth repellents) were considered as potential VOC sources inside apartment buildings for the first- and second-year post-occupancy stages, respectively.

An Empirical Study on Nonlinear Relationship between Product Modularity and Customer Satisfaction (제품의 모듈화 전략과 고객만족의 비선형적 관계에 대한 실증적 연구)

  • Hwang, Sunil;Suh, Eung-Kyo
    • The Journal of Industrial Distribution & Business
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    • v.9 no.2
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    • pp.47-55
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    • 2018
  • Purpose - To meet the needs of various customers in an uncertain market environment, many companies use product modularization strategies. Modularization of a product means that one product consists of several components and that the type of product can be changed according to the combination of components. The greatest feature of modularity is that changes in one component do not significantly affect the physical changes in the other component to which they are connected. Modularization of products is recognized as a very important strategy to reflect increasingly complicated customer requirements to products and respond to the needs of various markets. Many studies have been made in connection with the concept of mass customer satisfaction. There are many prior studies that modularization of such products positively affects the operational performance (manufacturing cost, fast delivery, etc.) and innovation of the product. However, excessive modularization has been found to have a negative effect on this performance. However, there are very few studies on the nonlinear relationship between product modularization and customer satisfaction. Supplementing these academically insufficient parts is very necessary when considering the current market environment. Research design, data, and methodology - In order to make up for the shortcomings of academic research in Korea, this study collects data through questionnaires in electronic, auto, and defense industry. This is because these industries are using modularity of products. based on lots of previous studies and information overload theory, we made two hypothesis and verify with empirical analysis. All 108 data were used. We used the R program and SPSS program for statistical verification. Results - As a result of the study, modularization of products showed positive relationship with customer satisfaction to a certain level. However, it has been found that when the modularization is over and beyond a certain level, there is a negative relationship with customer satisfaction. Conclusions - Excessive modularization of products can have a negative impact on customer satisfaction. This result can be understood as a result of human limited rationality due to information overload. Therefore, it is important for companies to apply appropriate modularity to product design.

Ground response of a gob-side gateroad suffering mining-induced stress in an extra thick coal seam

  • He, Fulian;Gao, Sheng;Zhang, Guangchao;Jiang, Bangyou
    • Geomechanics and Engineering
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    • v.22 no.1
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    • pp.1-9
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    • 2020
  • This paper presents an investigation of the ground response of a gob-side gateroad suffering mining stress induced by a 21 m-thick coal seam extraction. A field observation, including entry convergence and stress changes monitoring, was first conducted in the tailgate 8209. The observation results of entry convergence showed that, during the adjacent panel 8210 retreating period, the deformation of the gob-side gateroad experienced a continuous increase stage, subsequently, an accelerating increase stage, and finally, a slow increase stage. However, strong ground response, including roof bending deflection, rib extrusion and floor heave, occurred during the current panel 8209 retreating period, and the maximum floor heave reached 1530 mm. The stress changes within coal mass of the two ribs demonstrated that the gateroad was always located in the stress concentrated area, which responsible for the strong response of the tailgate 8209. Subsequently, a hydraulic fracture technique was proposed to pre-fracture the two hard roofs above the tailgate 8209, thus decreasing the induced disturbance on the tailgate. The validity of the above roof treatment was verified via field application. The finding of this study could be a reference for understanding the stability control of the gob-side gateroad in extra thick coal seams mining.

New Spectra in Female Sexology in Korea (여성 성의학의 새로운 지평(地平))

  • Koh, Min-Whan
    • Journal of Yeungnam Medical Science
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    • v.16 no.1
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    • pp.10-14
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    • 1999
  • The World Association for Sexology (WAS) will adopt a Declaration of Sexual Rights as basic and fundamental human rights August this year in Hong Kong. Two years ago WAS has been developing a Declaration of Sexual Rights in order to further promote sexual health and protect the sexual rights of everyone. Undoubtedly sexuality is one of the most intriguing subjects in the area of human behavior and psychology, and has been so since antiquity. The influence of sexual factors of human on all aspects of the society has been immense. The varieties of marriage, from traditional to the open marriage model are presented in front of our sight. The influences of women's movement in Korea, which has produced sexual, psychological, economic, political, familial and social changes look so small and the changes are not that much in America. But the profound effects of the women's movement affect on Korean society being realized as man's view of woman and woman's view of herself undergo constant change and reevaluation. With increased sexual awareness on the part of the public owing to mass media, for example AH-U-SEONG aired in TV and with increased emphasis on sexual matters in daily life, more and more physicians are being asked to deal with and manage sex-related problems in their daily practice. Yet, despite the obvious need for informed sexual counseling, doctors are often uncomfortable about sexual matters and many physicians have no special expertise in this area. So physicians concerned in sexology especially such as gynecologists, urologists, psychiatrists and endocrinologists must realize well about sex-related knowledge which is needed for counseling the patient as medical consumer and gap between reality and ideality in sexual diagnosis and treatment. Establishment of management system for the people who have sexual problems is strongly needed to promote sexual health and protect the sexual rights of everyone and for the Sexual Rights as basic and fundamental human rights.

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Aerosol Chemistry in the Marine Environment: Inference of Inter-logic Relationships from the Concentrations and Ratios of Sonic Constituents (해양환경의 에어로졸 화학- 농도와 함량비를 이용한 이온성분간의 관계에 대한 추론)

  • 김기현;이강웅
    • Journal of Korean Society for Atmospheric Environment
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    • v.14 no.2
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    • pp.143-152
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    • 1998
  • The aerosol concentrations of ionic components were measured on a daily basis from a coastal monitoring site located at Kosan, Cheju Island from 26 September to 5 October 1997 as a field-intensive for a LRTAP project The chemical species we investigated include most of important inorganic species (i.e., Cl-, NO3-, F-, SO42-, Na+, NH4+, and K+) and some organic species (i.e. formats, acetate, and methanesulfonate (MSA) ions). The concentration data of those important inorganic and organic species obtained during this study were evaluated to properly address their chemical and physical characteristics. Most of major inorganic components including sulfate, sodium, chloride, and potassium ions exhibited very conservative relationships with each other such that the concentration ratios of any pair are quite analogous to that of seawater ratio. Since the oceans serve as the major sources of ionic constituents, their concentration changes appear to be senstively reflected by the factors affecting air-sea processes such as an increase in wind speed or changes in wind direction. A comparative analysis of sulfur-containing species such as seasalt (SS) and nonseasalt (NSS) sulfate and MSA were also made to assess the factors influencing the S cycling. An evaluation of NSS/SS ratios suggests that most of sulfate be associated with NSS fraction rather than 55 one. The finding of lower MSA/NSS-SO42- ratio along with a line of physical evidence such as intrusion of anthropogenically affected air mass suggests that the oxidation of S species have been promoted under the conditions encountered during the study period. Finally, the concentration data of carboxylic species (such as formats and acetate ions) were also analyzed. Although the existence of temporal trends were difficult to assess, these data indicate that their contribution to the precipitation acidity may not be significant enough.

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A Response to Postural Response to Sine Curve Vestibular Electric Stimulation during Standing (기립자세동안 전정기관에 인가된 정현파 전류자극에 대한 자세균형 응답)

  • Lee, Ah-Reum;Yu, Mi;Kim, Jin-Ho;Kim, Dong-Wook;Kim, Jung-Ja
    • Journal of Biomedical Engineering Research
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    • v.31 no.3
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    • pp.210-216
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    • 2010
  • This study is vestibular electric stimulation applied between the mastoids during quiet standing elicits postural sway. The aim of this study was to characterize the postural sway response to continuous sinusoidal vestibular electric stimulation across various stimulus frequencies and amplitudes. Binaural bipolar sinusoidal vestibular electric stimulation was applied to the skin overlying the mastoid processes of 10 subjects while they stood on a force plate. The position of the center of pressure(COP) and signals at the feet are obtained on an force plate, while the head and whole body center of mass(COM) was measured with motion analysis system. The stimulus conditions included eight frequencies (1/64, 1/32, 1/16, 1/8, 1/4, 1/2, 1, and 2Hz) and six peak amplitudes (0.1, 0.25, 0.5, 0.7, 1 and 2mA). Each subject experienced one trial at each amplitude-frequency pair. The stimuli elicited sway in lateral plane in all subjects, as evidenced by changes in the stimulus frequency. Our results demonstrate that the vestibular system is sensitive to vestibular electric stimulation intensity changes and responds by altering the magnitude of the response accordingly.

Clinical and Radiologic Analysis of Posterior Apophyseal Ring Separation Associated with Lumbar Disc Herniation

  • Bae, Jung-Sik;Rhee, Woo-Tack;Kim, Woo-Jae;Ha, Seong-Il;Lim, Jae-Hyeon;Jang, Il-Tae
    • Journal of Korean Neurosurgical Society
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    • v.53 no.3
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    • pp.145-149
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    • 2013
  • Objective : We analyzed the clinical and radiologic features of posterior apophyseal ring separation (PARS) with lumbar disc herniation and suggest the proper management options according to the PARS characteristics. Methods : We reviewed case series of patients with PARS who underwent surgery of lumbar disc herniation. Preoperative symptoms, neurologic status, Body Mass Index, preoperative and postoperative Visual Analogue Scale (VAS) and Korean-Oswestry Disability Index (K-ODI) scores, operation types were obtained. PARS size, locations, the degree of resection were assessed. Results : PARS was diagnosed in 109 (7.5%) patients among 1448 patients given surgical treatment for single level lumbar disc herniation. There were 55 (50.5%) small PARS and 54 (49.5%) large PARS. Among the large PARS group, 15 (27.8%) had lower endplate PARS of upper vertebra at the level of disc herniation. Thirty-nine (72.2%) were upper endplate PARS of lower vertebra. Among the group with upper endplate PARS of lower vertebra, unresected PARS was diagnosed in 12 (30.8%) cases and resected PARS was diagnosed in 27 (69.2%) cases. VAS and K-ODI scores changes were $3.6{\pm}2.9$ and $5.4{\pm}6.4$ in the unresected PARS group, $5.8{\pm}2.1$ and $11.3{\pm}7.1$ in the resected PARS group. The group with upper endplate PARS of lower vertebra showed significant difference of VAS (p=0.01) and K-ODI (p=0.013) score changes between unresected and resected PARS groups. Conclusion : The large PARS of upper endplate in lower vertebra should be removed during the surgery of lumbar disc herniation. High level or bilateral side of PARS should be widely decompressed and arthrodesis procedures are necessary if there is a possibility of secondary instability.

Effect of Soy Isoflavone Supplementation on Bone Metabolism Marker and Urinary Mineral Excretion in Postmenopausal Women (대두 이소플라본 보충 섭취가 폐경 후 여성의 골대사 지표와 소변 무기질 배설량에 미치는 영향)

  • 이다홍;승정자
    • Journal of Nutrition and Health
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    • v.36 no.5
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    • pp.476-482
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    • 2003
  • We studied the effects of soy isoflavone supplements on bone metabolism marker (serum osteocalcin, urinary deoxypyridinoline) and urinary mineral excretion (urinary Ca, Mg, Zn) in 47 postmenopausal women. There were 24 participants in the treatment group and 23 in the control group. The treatment group consumed isoflavone extract capsules daily (which contained 90 mg of soy isoflavones) for 12 weeks. The study compared before and after isoflavone intake in the following areas: Physical examination, diet survey, bone metabolism marker and urinary mineral excretion. The average age of the treatment group was 64.6 years and that of the control group was 66.5 years. There were no significant differences between the two groups in terms of height, weight and body mass index. Both groups maintained a regular diet pattern in terms of their average daily nutrient intake. There were no significant differences between the treatment group (23.9 mg) and the control group (25.4 mg) in terms of daily isoflavone intake based on diet. The analysis of bone metabolism marker changes in the treatment group after 12 weeks of taking the isoflavone supplements demonstrated significant differences in the following: Serum osteocalcin (13.7 ng/mL in befor versus 6.8 ng/mL in after) and urinary deoxypyridinoline (5.9 nmol/mmol Cr in befor versus 4.5 nmol/mmol Cr in after). The subjects in the treatment group showed no significant difference in urinary Ca excretion. But the subjects showed a significant difference in urinary Mg (131.9 mg/day in befor versus 115.6 mg/day in after) and Zn (400.5 $\mu\textrm{g}$/day in befor versus 310.2 $\mu\textrm{g}$/day in after) excretion in the isoflavone treatment group at the levels of p<0.001, p<0.01, respectively. No changes were made in the intake of minerals. The composition of serum osteocalcin and urinary deoxypyridinoline, and indicators of bone metabolism, including the excretion Mg and Zn, significantly decreased. As a result, bone mineral loss was lessened. (Korean J Nutrition 36(5): 476~482, 2003)

The Effect of Nutrition Education and Excercise Program on Body Composition and Dietary Intakes, Blood Lipid and Physical Fitness in Obese Women (영양교육과 운동중재 프로그램이 성인비만여성의 신체성분과 식이섭취, 혈중지질 및 기초체력에 미치는 효과)

  • Lee, Hee-Seung;Lee, Ji-Won;Chang, Nam-Soo;Kim, Ji-Myung
    • Journal of Nutrition and Health
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    • v.42 no.8
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    • pp.759-769
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    • 2009
  • This study investigated the effects of the nutrition education and exercise program on body composition, dietary intakes and physical fitness in obese women. The subjects were 44 obese women (BMI${\geq}$ 25 kg/$m^2$) who had been participating in nutrition education (1 time/week) and exercise program (3 time/week) for 12 weeks. Nutrition education was focused on low energy, high protein and low carbohydrate diet to reduce the body weight and improve the diet quality. To evaluate the effectiveness of the program, daily nutrient intakes were assessed by 24-hour recall method. Body composition, blood lipid profiles and physical fitness test were assessed before and after the intervention. After the intervention, body weight, BMI, percent body fat, soft lean mass and waist/hip ratio were significantly decreased (p < 0.001). Fasting blood sucrose, total cholesterol, LDL-cholesterol and atherogenic index (AI) were significantly decreased (p < 0.001), while HDLcholesterol was significantly increased (p < 0.001). Energy adjusted protein, fiber, vitamin A, vitamin $B_2$, vitamin $B_6$, vitamin C, vitamin E, niacin and folate were significantly increased. After the intervention, the muscle endurance, muscle strength, agility, balance were significantly increased. The changes in obesity indices (body weight, BMI, percent body fat, waist-hip ratio) were correlated with the changes of the nutrient intakes, serum lipid profiles, physical fitness. These results show that nutrition education and exercise program was effective not only for weight reduction but also for the improvement of physical strength and cardiovascular disease risk factors in obese women.

Tumor bed volumetric changes during breast irradiation for the patients with breast cancer

  • Chung, Mi Joo;Suh, Young Jin;Lee, Hyo Chun;Kang, Dae Gyu;Kim, Eun Joong;Kim, Sung Hwan;Lee, Jong Hoon
    • Radiation Oncology Journal
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    • v.31 no.4
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    • pp.228-233
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    • 2013
  • Purpose: The aim of this study was to evaluate changes in breast tumor bed volume during whole breast irradiation (WBI). Materials and Methods: From September 2011 to November 2012, thirty patients who underwent breast-conserving surgery (BCS) followed by WBI using computed tomography (CT) simulation were enrolled. Simulation CT scans were performed before WBI (CT1) and five weeks after the breast irradiation (CT2). The tumor bed was contoured based on surgical clips, seroma, and postoperative change. We retrospectively analyzed the factors associated with tumor bed volumetric change. Results: The median tumor bed volume on CT1 and CT2 was 29.72 and 28.6 mL, respectively. The tumor bed volume increased in 9 of 30 patients (30%) and decreased in 21 of 30 patients (70%). The median percent change in tumor bed volume between initial and boost CT was -5%. Seroma status (p = 0.010) was a significant factor in tumor bed volume reduction of 5% or greater. However, patient age, body mass index, palpability, T stage, axillary lymph node dissection, and tumor location were not significant factors for tumor bed volumetric change. Conclusion: In this study, volumetric change of tumor bed cavity was frequent. Patients with seroma after BCS had a significant volume reduction of 5% or greater in tumor bed during breast irradiation. Thus, resimulation using CT is indicated for exquisite boost treatment in breast cancer patients with seroma after surgery.