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Extending the calibration between empirical influence function and sample influence function to t-statistic (경험적 영향함수와 표본영향함수 간 차이 보정의 t통계량으로의 확장)

  • Kang, Hyunseok;Kim, Honggie
    • The Korean Journal of Applied Statistics
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    • v.34 no.6
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    • pp.889-904
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    • 2021
  • This study is a follow-up study of Kang and Kim (2020). In this study, we derive the sample influence functions of the t-statistic which were not directly derived in previous researches. Throughout these results, we both mathematically examine the relationship between the empirical influence function and the sample influence function, and consider a method to approximate the sample influence function by the empirical influence function. Also, the validity of the relationship between an approximated sample influence function and the empirical influence function is verified by a simulation of a random sample of size 300 from normal distribution. As a result of the simulation, the relationship between the sample influence function which is derived from the t-statistic and the empirical influence function, and the method of approximating the sample influence function through the empirical influence function were verified. This research has significance in proposing both a method which reduces errors in approximation of the empirical influence function and an effective and practical method that evolves from previous research which approximates the sample influence function directly through the empirical influence function by constant revision.

Evaluation on the effectiveness of the activation policy for Seongsu handmade shoes industry (성수동 수제화 산업 활성화 정책의 효과 평가)

  • Kim, Ji-Yeon;Jeong, Jae-Chul;Sang, Jeong Seon;Park, Myung-Ja
    • Journal of the Korea Fashion and Costume Design Association
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    • v.20 no.4
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    • pp.147-162
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    • 2018
  • The purpose of this study is to conduct a comprehensive and objective evaluation on the effectiveness of the activation policies for the Seongsu handmade shoe industry and to suggest the direction of more effective future policies using the results. The list of the activation policies for the Seongsu handmade shoe industry was investigated and awareness, appropriateness, effectiveness, and satisfaction were measured from the representatives of the Seongsu handmade shoe companies via an off-line survey. A total of 61 usable data sets were statistically analyzed. Based on the evaluation result of the policies, a focus group interview with 6 representatives of the Seoungsu handmade shoe industry was conducted to investigate the causes and effectiveness of the policies and the problems pertaining to those policies. The awareness, effectiveness, and satisfaction of the policies were evaluated as negatives, while the appropriateness of the policies was evaluated as a positive. The manufacturers of the handmade shoes evaluated policies that improve the environment of the workplace higher and evaluated the handmade shoes education policy lower than the distributors and raw materials suppliers. The problems with the activation policies for the Seongsu handmade shoes industry were found to be structural problems, issues with the implementation of the policies, and that the fact that the policies did not reflect the reality of the industry.

Radiation measurement and imaging using 3D position sensitive pixelated CZT detector

  • Kim, Younghak;Lee, Taewoong;Lee, Wonho
    • Nuclear Engineering and Technology
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    • v.51 no.5
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    • pp.1417-1427
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    • 2019
  • In this study, we evaluated the performance of a commercial pixelated cadmium zinc telluride (CZT) detector for spectroscopy and identified its feasibility as a Compton camera for radiation monitoring in a nuclear power plant. The detection system consisted of a $20mm{\times}20mm{\times}5mm$ CZT crystal with $8{\times}8$ pixelated anodes and a common cathode, in addition to an application specific integrated circuit. The performance of the various radioisotopes $^{57}Co$, $^{133}Ba$, $^{22}Na$, and $^{137}Cs$ was evaluated. In general, the amplitude of the induced signal in a CZT crystal depends on the interaction position and material non-uniformity. To minimize this dependency, a drift time correction was applied. The depth of each interaction was calculated by the drift time and the positional dependency of the signal amplitude was corrected based on the depth information. After the correction, the Compton regions of each spectrum were reduced, and energy resolutions of 122 keV, 356 keV, 511 keV, and 662 keV peaks were improved from 13.59%, 9.56%, 6.08%, and 5%-4.61%, 2.94%, 2.08%, and 2.2%, respectively. For the Compton imaging, simulations and experiments using one $^{137}Cs$ source with various angular positions and two $^{137}Cs$ sources were performed. Individual and multiple sources of $^{133}Ba$, $^{22}Na$, and $^{137}Cs$ were also measured. The images were successfully reconstructed by weighted list-mode maximum likelihood expectation maximization method. The angular resolutions and intrinsic efficiency of the $^{137}Cs$ experiments were approximately $7^{\circ}-9^{\circ}$ and $5{\times}10^{-4}-7{\times}10^{-4}$, respectively. The distortions of the source distribution were proportional to the offset angle.

Study on French Film Fund Policy -Focusing on CNC's support project for film productions (프랑스 영화기금정책 연구 -CNC 제작지원 사업을 중심으로)

  • Kim, Hyun-Hee
    • Journal of the Korea Convergence Society
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    • v.10 no.9
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    • pp.133-140
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    • 2019
  • The Korean Film Council which manages the Film Development Fund carried out a number of projects to support film production, distribution, and film policies. Also, this organization participated in promoting advanced film technology and foreign film location by constituting an incentive support. The projects consist of support for the operation of Namyangju filming studio and the film information system as well. It is necessary to scrutinize the projects regarding support for film production, which is the largest and most important among the whole projects, for continuous development of the Korean film industry. this study reviwed the fundraising status, budget, and support projects of the Center for National Film/Video Center CNC which operates the film fund in France analyzed film production support policy of the CNC. Through this, we verified necessity of stable financing and funding of the Korean Film Development Fund, support for creation of film music and support for overseas filming, and prepared activation plans for film co-production.

A cost-effective method to prepare size-controlled nanoscale zero-valent iron for nitrate reduction

  • Ruiz-Torres, Claudio Adrian;Araujo-Martinez, Rene Fernando;Martinez-Castanon, Gabriel Alejandro;Morales-Sanchez, J. Elpidio;Lee, Tae-Jin;Shin, Hyun-Sang;Hwang, Yuhoon;Hurtado-Macias, Abel;Ruiz, Facundo
    • Environmental Engineering Research
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    • v.24 no.3
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    • pp.463-473
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    • 2019
  • Nanoscale zero-valent iron (nZVI) has proved to be an effective tool in applied environmental nanotechnology, where the decreased particle diameter provides a drastic change in the properties and efficiency of nanomaterials used in water purification. However, the agglomeration and colloidal instability represent a problematic and a remarkable reduction in nZVI reactivity. In view of that, this study reports a simple and cost-effective new strategy for ultra-small (< 7.5%) distributed functionalized nZVI-EG (1-9 nm), with high colloidal stability and reduction capacity. These were obtained without inert conditions, using a simple, economical synthesis methodology employing two stabilization mechanisms based on the use of non-aqueous solvent (methanol) and ethylene glycol (EG) as a stabilizer. The information from UV-Vis absorption spectroscopy and Fourier transform infrared spectroscopy suggests iron ion coordination by interaction with methanol molecules. Subsequently, after nZVI formation, particle-surface modification occurs by the addition of the EG. Size distribution analysis shows an average diameter of 4.23 nm and the predominance (> 90%) of particles with sizes < 6.10 nm. Evaluation of the stability of functionalized nZVI by sedimentation test and a dynamic light-scattering technique, demonstrated very high colloidal stability. The ultra-small particles displayed a rapid and high nitrate removal capacity from water.

Rigid plastic analysis for the seismic performance evaluation of steel storage racks

  • Montuori, Rosario;Gabbianelli, Giammaria;Nastri, Elide;Simoncelli, Marco
    • Steel and Composite Structures
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    • v.32 no.1
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    • pp.1-19
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    • 2019
  • The aim of the paper is the prediction of the seismic collapse mode of steel storage pallet racks under seismic loads. The attention paid by the researchers on the behaviour of the industrial steel storage pallets racks is increased over the years thanks to their high dead-to-live load ratio. In fact, these structures, generally made by cold-formed thin-walled profiles, present very low structural costs but can support large and expensive loads. The paper presents a prediction of the seismic collapse modes of multi-storey racks. The analysis of the possible collapse modes has been made by an approach based on the kinematic theorem of plastic collapse extended to the second order effects by means of the concept of collapse mechanism equilibrium curve. In this way, the dissipative behaviour of racks is determined with a simpler method than the pushover analysis. Parametric analyses have been performed on 24 racks, differing for the geometric layout and cross-section of the components, designed in according to the EN16618 and EN15512 requirements. The obtained results have highlighted that, in all the considered cases, the global collapse mechanism, that is the safest one, never develops, leading to a dangerous situation that must be avoided to preserve the structure during a seismic event. Although the studied racks follow all the codes prescriptions, the development of a dissipative collapse mechanism is not achieved. In addition, also the variability of load distribution has been considered, reflecting the different pallet positions assumed during the in-service life of the racks, to point out its influence on the collapse mechanism. The information carried out from the paper can be very useful for designers and manufacturers because it allows to better understand the racks behaviour in seismic load condition.

The Flora of Subalpine Vascular Plants in Seseok Area of Jirisan National Park (지리산국립공원 세석지역의 아고산 관속식물상)

  • Noh, Il;Chung, Jae-Min;Cho, Min-Gi;Kim, Tae-Woon;Moon, Hyun-Shik
    • Journal of Climate Change Research
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    • v.8 no.3
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    • pp.201-211
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    • 2017
  • This study was conducted to investigate the vascular plants which can be an indicator of environmental change in Seseok of Jirisan National Park. The purpose of this study was to find out the basic information for the subalpine species. This study showed that the area had a total 295 taxa including 63 families, 177 genus, 252 species, 2 subspecies, 36 variants 5 forms and Pte-Q was 1.7. Among them, Korea endemic plants were 15 taxa such as Abies koreana. Rare plants were 14 taxa such as Viola diamantiaca. Naturalized plants consisted of 5 taxa such as Rumex crispus. The floristic regional indicator plants found in surveyed area were 72 taxa comprising 3 taxa of grade V, 7 taxa of grade IV and 24 taxa of grade III. In summary, The subalpine plants of the survey region consisted of 37 taxa including Abies koreana and Gymnadenia cucullata. As rare plants distributed in subalpine zone respond sensitively to climate change, accuracy distribution range, environmental characteristics of habitat and population dynamics of rare plants should be evaluated quantitatively.

Damage detection of shear buildings using frequency-change-ratio and model updating algorithm

  • Liang, Yabin;Feng, Qian;Li, Heng;Jiang, Jian
    • Smart Structures and Systems
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    • v.23 no.2
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    • pp.107-122
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    • 2019
  • As one of the most important parameters in structural health monitoring, structural frequency has many advantages, such as convenient to be measured, high precision, and insensitive to noise. In addition, frequency-change-ratio based method had been validated to have the ability to identify the damage occurrence and location. However, building a precise enough finite elemental model (FEM) for the test structure is still a huge challenge for this frequency-change-ratio based damage detection technique. In order to overcome this disadvantage and extend the application for frequencies in structural health monitoring area, a novel method was developed in this paper by combining the cross-model cross-mode (CMCM) model updating algorithm with the frequency-change-ratio based method. At first, assuming the physical parameters, including the element mass and stiffness, of the test structure had been known with a certain value, then an initial to-be-updated model with these assumed parameters was constructed according to the typical mass and stiffness distribution characteristic of shear buildings. After that, this to-be-updated model was updated using CMCM algorithm by combining with the measured frequencies of the actual structure when no damage was introduced. Thus, this updated model was regarded as a representation of the FEM model of actual structure, because their modal information were almost the same. Finally, based on this updated model, the frequency-change-ratio based method can be further proceed to realize the damage detection and localization. In order to verify the effectiveness of the developed method, a four-level shear building was numerically simulated and two actual shear structures, including a three-level shear model and an eight-story frame, were experimentally test in laboratory, and all the test results demonstrate that the developed method can identify the structural damage occurrence and location effectively, even only very limited modal frequencies of the test structure were provided.

Visual Analysis of Regional Variations in Antidepressant Use and Suicide Rate (항우울제 사용 및 자살률의 지역적 편차에 대한 시각적 분석)

  • Kim, Ho-Jung;Lee, Iyn-Hyang
    • Korean Journal of Clinical Pharmacy
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    • v.28 no.4
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    • pp.308-319
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    • 2018
  • Background: Some mental illnesses such as depression are known to be one of the risk factors of suicide and proper antidepressant therapy can reduce suicidal behavior. Objectives: This study aimed to analyze regional variations in antidepressant consumption and adherence, suicide rate, prevalence of suicide related mental disorders, and access to relevant healthcare services. Methods: Cross-sectional analyses were conducted using National Patients Sample data compiled by the Health Insurance Review and Assessment Service between 2014 and 2016. We included patients who had a diagnosis record of suicide related mental disorders during the study period. Cause of death statistics and National health and medical statistics were used to identify suicide rate and distribution of healthcare service. We conducted visual analyses, chi-squared tests, independent t-tests and correlation analyses to demonstrate regional variations. Results: Between 2014 and 2016, the average prevalence of suicide related mental disorders was 5.4 per cent. Suicide rate and prevalence of suicide related mental disorders were higher in Gangwon, Chungcheong, and Jeolla (p < 0.001), and lower in Seoul (p < 0.001) than the national average. Unexpectedly, regional variations in antidepressant consumption were seen in the limited area including Daejeon, Chungnam and Gyeongnam (p < 0.05). The number of mild patient-centered clinics was associated positively with antidepressant consumption (p < 0.01) and associated negatively with suicide rate (p < 0.01). Conclusion: There were some regional variations in prevalence of suicide related mental disorders, antidepressant adherence and suicide rate. The higher level of antidepressant therapy and the lower level of suicide rates were seen in regions with easy access to mild patient-centered clinics.

A Study on the Spatial Position Problem of PM Monitoring Stations Using Voronoi Technique and Density Analysis (보로노이 기법과 밀도분석을 활용한 미세먼지 측정소 공간적 위치 문제 연구)

  • Jeong, Jong-Chul
    • Journal of Cadastre & Land InformatiX
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    • v.48 no.2
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    • pp.185-195
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    • 2018
  • In the Seoul Metropolitan City, the PM(pariculate matter) application used by the citizens provides the PM concentration of the nearest monitoring stations located on the PM monitoring stations. Currently, the selecting method of the PM monitoring network considered by the Ministry of Environment is based on considering the monitoring station distribution and population density only. In this study, we analyzed the distance between PM monitoring station and the administrative center point in addition to the above considerations. The number of test sites was verified and the range of coverage of each monitoring stations was indicated by using the Voronoi algorithm and hexagon grid. The spatial position problem of the PM monitoring station was suggested by spatial data analysis. The variables of spatial data analysis are single-family houses, apartments, $1^{st}$ class neighborhood, $2^{nd}$ class neighborhood, garbage disposal plant, hazardous material disposal facility, factory, and the density map. The analysis result of the selection criterion considering the additional variables for new PM monitoring stations was presented, in addition to the selection criteria provided by the Ministry of Environment.