• Title/Summary/Keyword: Selective sampling

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Characteristics of Particle Size Distributions Generated in the Vicinity of Building Blasting Demolition Sites (발파해체현장에서 발생하는 순간분진의 입경분포 특성)

  • Lee, Kyoung-Hee;Kim, Hyo-Jin;Park, Chan-Gyu;Ko, Kwang-Baik
    • Journal of Environmental Science International
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    • v.18 no.1
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    • pp.41-47
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    • 2009
  • In building demolition work, major dust-generating activities are blasting concrete and rock. The aim of this study was to find the characteristic of particle size of dusts which were generated during building demolition work using explosion. The DustMate of the Turnkey-Instruments Ltd. was used for particulate size-selective sampling of the four sites. TSP(Total Suspended Particle), PM10(Particle Matter $10{\mu}m$), PM2.5(Particle Matter $2.5{\mu}m$), and PM1.0(Particle Matter $1.0{\mu}m$) were measured during building demolition work using explosion. The large particulate (higher than the diameter $10{\mu}m$) showed to be higher than 50%. The particulate ranged from $10{\mu}m\;to\;2.5{\mu}m$ showed about 30-40%. PM2.5 was not scarcely detected in the samples collected for building demolition work using explosion. We conclude that the dust generated during building demolition work using explosion has not most respirable particulate.

가족배경이 자녀의 성격형성에 미치는 영향에 관한 연구 -자녀의 수 및 성 구성을 중심으로-

  • Choe, Jeong
    • Korea journal of population studies
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    • v.7 no.1
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    • pp.78-123
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    • 1984
  • This study is attempting to examine the possible determinants of the rise of the sex ratio at birth from 106 to 110 in past decade in Taiwan. The basic hypothesis for the sudden rise of the sex ratio at birth is due to a combination of prenatal sex determination and abortion. The reasoning for this hypothesis involves three types of considerations - motivation, norm, and access. The theory is evaluated by analyzing data from birth registration and a large and representative sampie of Taiwanese wives of childbearing age. The empirical data seem to support the theoretical preposition and the basic hypothesis that the rise of the sex ratio at birth in Taiwan is due to a combination of prenatal sex determination and abortion. There is striking evidence of son-preference in the rise of the sex ratio at birth in higher birth order. In 1990 the sex ratio was 119 for third births and 128 for fourth and fifth births compared to the expected 106. Also, the 1991 KAP data indicated that women who have only daughters but no any son are more likely to make prenatal sex screening and terminate their pregnancies in male live births at higher birth order. Obviously, genetic diagnosis through chorionic villus sampling which was available in recent years was misused for prenatal sex determination and sex selective abortion.

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p-Adaptive Mesh Refinement of Plate Bending Problem by Modified SPR Technique (수정 SPR 기법에 의한 휨을 받는 평판문제의 적응적 p-체눈 세분화)

  • Jo, Jun-Hyung;Lee, Hee-Jung;Woo, Kwang-Sung
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.481-486
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    • 2007
  • The Zienkiewicz-Zhu(Z/Z) error estimate is slightly modified for the hierarchical p-refinement, and is then applied to L-shaped plates subjected to bending to demonstrate its effectiveness. An adaptive procedure in finite element analysis is presented by p-refinement of meshes in conjunction with a posteriori error estimator that is based on the superconvergent patch recovery(SPR) technique. The modified Z/Z error estimate p-refinement is different from the conventional approach because the high order shape functions based on integrals of Legendre polynomials are used to interpolate displacements within an element, on the other hand, the same order of basis function based on Pascal's triangle tree is also used to interpolate recovered stresses. The least-square method is used to fit a polynomial to the stresses computed at the sampling points. The strategy of finding a nearly optimal distribution of polynomial degrees on a fixed finite element mesh is discussed such that a particular element has to be refined automatically to obtain an acceptable level of accuracy by increasing p-levels non-uniformly or selectively. It is noted that the error decreases rapidly with an increase in the number of degrees of freedom and the sequences of p-distributions obtained by the proposed error indicator closely follow the optimal trajectory.

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A study on Characteristics of Airborne Dusts in Seoul Subway Stations (서울 지하철 내 공기 중 먼지의 특성에 관한 연구)

  • 김진경;백남원
    • Journal of Environmental Health Sciences
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    • v.30 no.2
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    • pp.154-160
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    • 2004
  • The purpose of this study was to evaluate airborne concentrations and characteristics of TSP, IPM, TPM and RPM in Seoul subway stations. Sampling was performed at 14 stations from April 11 to 29, 2002. Size-selective dust concentrations and metal concentrations were measured by gravimetric method and ICP-AES, respectively. The geometric mean of TSP, IPM, TPM and RPM concentrations in Seoul subway stations were 176$\mu\textrm{g}$/㎥, 348$\mu\textrm{g}$/㎥, 158$\mu\textrm{g}$/㎥ and 104$\mu\textrm{g}$/㎥, respectively. Dust concentrations in pathway were the highest and those in lobby were the lowest. The size distribution of dusts was significantly different by location of collection. When the deposition rate into pulmonary gas exchange region was estimated by size distribution, the deposition rate of dust collected from platform was higher than those of dust collected from lobby and pathway. The lower the basement levels were, the higher the deposition rates of dusts into tracheobronchial region and gas exchange region were. Copper and iron concentrations measured in platform higher were than those in other areas.

A Study on the Culture of Clothing of Subgroups among Adolescents by Residence (주거지역에 따른 청소년 내 하위집단들의 복식문화 연구)

  • 남궁윤선
    • Journal of the Korean Society of Clothing and Textiles
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    • v.23 no.5
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    • pp.623-634
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    • 1999
  • The purpose of this study is to explore the culture of clothing of subgroups among adolescents by residence. In this research informants were selected by selective sampling and ethnographic methods such as field work depth interviews and open-ended descriptions were employed to interpret their culture of clothing. The results were followed. First our adolescents enjoyed the popular song as leisure and these popular culture was their inspiration source of style. Second adolescents were grouping the Kang-Bouk and the adolescents group preferred the style of popular singers and the Kang-Nam adolescents group preferred the musical competence of singers and specific type particularly Hip-Hop style. And in acception pattern of fashion style the Kang-Bouk groups accepted the recent fashion style continuously and wanted to be striking while the Kang-Nam groups accepted the various Hip-Hop styles and sought to comfort and suitability of that style. Third to consider the connotations of marketing the Kan-Bouk groups shopped on the street perceived as fashionable among peer groups and sought to the lower price but the Kang-Nam groups used the shops selling their original ip-Hop style without regard to the price and sites. Although there existed a two years' difference between the first and the second research(1996-1998) subgroups among adolescents according to the residence have had their own culture of clothing constantly. And a segmentation tendency by clothing behavior within the same adolescent generation is revealed more visibly.

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Sex Preference and Sex Ratio at Birth: the Case of Taiwan (대만의 남아선호와 출생시 성비의 불균형)

  • Chang, Ming-cheng
    • Korea journal of population studies
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    • v.17 no.2
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    • pp.98-115
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    • 1994
  • This study is attempting to examine the possible determinants of the rise of the sex ratio at birth from 106 to 110 in past decade in Taiwan. The basic hypothesis for the sudden rise of the sex ratio at birth is due to a combination of prenatal sex determination and abortion. The reasoning for this hypothesis involves three types of considerations - motivation, norm, and access. The theory is evaluated by analyzing data from birth registration and a large and representative sampie of Taiwanese wives of childbearing age. The empirical data seem to support the theoretical preposition and the basic hypothesis that the rise of the sex ratio at birth in Taiwan is due to a combination of prenatal sex determination and abortion. There is striking evidence of son-preference in the rise of the sex ratio at birth in higher birth order. In 1990 the sex ratio was 119 for third births and 128 for fourth and fifth births compared to the expected 106. Also, the 1991 KAP data indicated that women who have only daughters but no any son are more likely to make prenatal sex screening and terminate their pregnancies in male live births at higher birth order. Obviously, genetic diagnosis through chorionic villus sampling which was available in recent years was misused for prenatal sex determination and sex selective abortion.

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Influence of Electronic Word of Mouth on Visitor's Interest to Tourism Destinations

  • APRILIA, Fitri;KUSUMAWATI, Andriani
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.2
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    • pp.993-1003
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    • 2021
  • The contribution made by the tourism sector is strategic enough to provide job opportunities and increase the state's foreign exchange which will be followed by development in the information and technology sectors. The population of this study includes all domestic tourists who visit the Batu City Angkut Museum over 17 years of age and who have obtained information via eWOM from other tourists. Based on the measurement, a minimum of 160 respondents must be selected as the research sample. Non-probability sampling techniques are used to select samples. Social media had been used by companies to provide information, services, and products related to tourism, and it was utilized by tourists to share information about their traveling experiences. Nowadays, tourists have become more selective and critical in selecting their destinations as they have become good observant in finding adequate information about certain destinations before deciding to visit the place. This reaction can be influenced by positive eWOM communication, positive image, and trust given to certain tourist destinations. Therefore, improving the number of visits requires the management of certain tourism service companies to apply proper marketing strategy and provide various advantages and best service quality to attract more visitors and give satisfaction to visitors.

Efficient 3D Object Simplification Algorithm Using 2D Planar Sampling and Wavelet Transform (2D 평면 표본화와 웨이브릿 변환을 이용한 효율적인 3차원 객체 간소화 알고리즘)

  • 장명호;이행석;한규필;박양우
    • Journal of KIISE:Computer Systems and Theory
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    • v.31 no.5_6
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    • pp.297-304
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    • 2004
  • In this paper, a mesh simplification algorithm based on wavelet transform and 2D planar sampling is proposed for efficient handling of 3D objects in computer applications. Since 3D vertices are directly transformed with wavelets in conventional mesh compression and simplification algorithms, it is difficult to solve tiling optimization problems which reconnect vertices into faces in the synthesis stage highly demanding vertex connectivities. However, a 3D mesh is sampled onto 2D planes and 2D polygons on the planes are independently simplified in the proposed algorithm. Accordingly, the transform of 2D polygons is very tractable and their connection information Is replaced with a sequence of vertices. The vertex sequence of the 2D polygons on each plane is analyzed with wavelets and the transformed data are simplified by removing small wavelet coefficients which are not dominant in the subjective quality of its shape. Therefore, the proposed algorithm is able to change the mesh level-of-detail simply by controlling the distance of 2D sampling planes and the selective removal of wavelet coefficients. Experimental results show that the proposed algorithm is a simple and efficient simplification technique with less external distortion.

Endocrinological Results of the Transsphenoidal Microsurgery for Cushing's Disease (쿠싱병에 대한 경접형동접근법의 내분비학적 결과)

  • Kim, Joon Soo;Kim, Chang Jin;Ha, Sang Soo;Kim, Jung Hoon;Lee, Jung Gyo;Kwun, Byung Duk;Hong, Sung Kwan;Lee, Ki Up;Lee, Bong Jae;Kim, Yong Jae;Choi, Choong Kon;Lee, Ho Gyu
    • Journal of Korean Neurosurgical Society
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    • v.30 no.5
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    • pp.611-621
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    • 2001
  • Objective : We analyzed the clinical and endocrinological results of the transsphenoidal microsurgery for ACTH secreting pituitary adenomas. Marerials and Methods : From October 1995 to August 2000, 18 patients underwent transsphenoidal microsurgery for Cushing's disease. We analyzed the surgical results of 17 patients, one patient who was previously operated from other hospital was excluded. Age of the patients were 18 to 61 years old(mean 37.7), male to female ratio was 1 : 3.3, and follow-up period was 3 to 50 months(mean 20.3). The selection of candidates for transsphenoidal exploration was based on endocrinologic criteria. Magnetic resonance imaging was the preferred radiologic test. Selective inferior petrosal sinus sampling of adrenocorticotropic hormone futher refined the diagnosis when endocrinologic and radiologic procedures were not definitive. Results : Results of the preoperative endocrinological test were : level of serum ACTH 29.4 to $225{\mu}g/dL$(mean $93.88{\mu}g/dL$) ; serum cortisol 11.9 to $47.5{\mu}g/dL$(mean $27.49{\mu}g/dL$) ; 24-hour urine free cortisol 235 to $1019{\mu}g/day$(mean $571.0{\mu}g/day$). Inferior petrosal sinus sampling for ACTH was performed in 11 patients and all were confirmed by Cushing's disease and we could predict the laterality of the tumor in 9 of 11 patients. We performed transsphenoidal selective adenomectomy in 5 patients, adenomectomy and subtotal hypophysectomy in 2 patients, adenomectomy and partial hypophysectomy in 9 patients, and in the remaining one patient, hemihypophysectomy followed by total hypophysectomy due to remission failure. Fifteen of 17 patients(88.2%) showed endocrinological remission. Glucocorticoid replacement therapy was performed in all the patients who showed remission for 1 to 24 months(mean 5.9 months), and 6 patients received steroid over 6 months. Conclusion : We conclude that the direct demonstration of a tumor in the pituitary gland by MRI is the most important and definitive diagnostic tool and the location of a mass should be confirmed with increased level of ACTH by the inferior petrosal sinus sampling. Transsphenoidal microsurgery is effective treatment modality for Cushing's disease and the immediate postoperative evaluation of the surgical resection of the tumor is very important. The patients should show hypocortisolism, decreased, subnormal serum ACTH and cortisol levels and 24-hours urine free cortisol. We performed 18 transsphenoidal microsurgery for Cushing's disease in 17 patients and 15 patients(88.2%) showed endocrinological remission.

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The Selective p-Distribution for Adaptive Refinement of L-Shaped Plates Subiected to Bending (휨을 받는 L-형 평판의 적응적 세분화를 위한 선택적 p-분배)

  • Woo, Kwang-Sung;Jo, Jun-Hyung;Lee, Seung-Joon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.20 no.5
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    • pp.533-541
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    • 2007
  • The Zienkiewicz-Zhu(Z/Z) error estimate is slightly modified for the hierarchical p-refinement, and is then applied to L-shaped plates subjected to bending to demonstrate its effectiveness. An adaptive procedure in finite element analysis is presented by p-refinement of meshes in conjunction with a posteriori error estimator that is based on the superconvergent patch recovery(SPR) technique. The modified Z/Z error estimate p-refinement is different from the conventional approach because the high order shape functions based on integrals of Legendre polynomials are used to interpolate displacements within an element, on the other hand, the same order of basis function based on Pascal's triangle tree is also used to interpolate recovered stresses. The least-square method is used to fit a polynomial to the stresses computed at the sampling points. The strategy of finding a nearly optimal distribution of polynomial degrees on a fixed finite element mesh is discussed such that a particular element has to be refined automatically to obtain an acceptable level of accuracy by increasing p-levels non-uniformly or selectively. It is noted that the error decreases rapidly with an increase in the number of degrees of freedom and the sequences of p-distributions obtained by the proposed error indicator closely follow the optimal trajectory.