• Proceedings of the Korean Society for Quality Management Conference
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• 2004.04a
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• pp.70-75
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• 2004

In actual manufacturing industries, process capability indices(PCI) are used to determine whether a production process is capable of producing items within a specified specification limits. We study some vector-valued PCIs $C_p=(C_{px},\;C_{py})$ and $C_{pk}=(C_{pkx},\; C_{pky})$ in this article. We propose some asymptotic confidence regions of PCIs with bootstrapping and examine the performance of those asymptotic confidence regions under the assumption of bivariate normal distribution.

• Journal of Korean Society for Quality Management
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• v.41 no.2
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• pp.233-248
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• 2013

Purpose: This study develops heuristic process capability indices (PCIs) using distribution-decomposition methods and evaluates the performances. The heuristic methods decompose the variation of a quality characteristic into upper and lower deviations and adjust the value of the PCIs using decomposed deviations in accordance with the skewness. The weighted variance(WV), new WV(NWV), scaled WV(SWV), and weighted standard deviation(WSD) methods are considered. Methods: The performances of the heuristic PCIs are investigated under the varied situations such as various skewed distributions, sample sizes, and specifications. Results: WV PCI is the best under the normal populations, WSD and SWV PCIs are the best under the low skewed populations, NWV PCI is the best under the moderate and high skewed populations. Conclusion: Comprehensive analysis shows that the NWV method is most adequate for a practical use.

• Journal of the Korea Safety Management & Science
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• v.5 no.3
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• pp.145-156
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• 2003

As we understand it, Process Capability indices are intended to provide single-number assessments of ability to meet specification limits on quality characteristics of interest. As a consequence of the varied ways in which PCIs are used, there have been two natural lines of research work: $\circled1$ studies on the properties of PCIs and their estimators in many different environments; $\circled2$ construction of new PCIs purporting to have better properties in certain circumstances. The most of existing process capability indices are concerned with the single variable. But, in many cases, a quality characteristic is composed with several factors. In that case, we want to know the integrated process capability of a quality characteristic not those of each factor. In this paper, we proposed a new multivariate system process capability index called $MSPCI:SC_{psk}$ which is the geometric mean of performance measure $C_{psk}$'S, and will be used as the criterion to assess multiple response process designs. Numerical illustration is done for $SC_{psk}$, $\overline{C_p}$(f), Cp, Cpk, Cpm, and Cpsk.

• Journal of Environmental Impact Assessment
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• v.7 no.2
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• pp.89-102
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• 1998

The purpose of this study is to seek AEI(Air Environmental Indices), PSI(Pollutant Standard Index) and the urban air quality control goal(the best available alternative energy program) by assessing the best ratio of energy types used in urban enterprises, based on harmful health effect and air quality standard and costs. This study is focused on an urban area(Puchun), where area sourcees are associated with heavy traffic, large population, and its industrial sources with large emissions. In the first step, air modeling, estimation of AEI and PSI, and benefit-cost analysis were carried out. In the second step, we assessed that 660 scenarios about the ratio of B-C oil, light oil and LNG used in urban enterprises with regard to air quality and cost. In the third step, the best available alternative energy program was selected for the ratio of energy species(B-C oil, light oil and LNG) by using the lexicographic method. From the emission analysis, main source of $NO_2$ is identified as industries and air quality is evaluated according to the ratio of B-C oil, light oil and LNG used in urban enterprise. The modeling data of TSP, $SO_2$, $NO_2$, CO, $O_3$, by ISC3 and PBM are respectively $118{\mu}g/m^3$, 0.027ppm, 0.025ppm, 2.0ppm, 0.55ppm in indurstrial area. That data are close to Environmental Air Quality Standard. By means of sensitivity analysis, we obtained the difference in concentration between the areas(Nae-dong, Joong-dong) according to the ratio of B-C oil, light oil and LNG used in the industries. From the result of alternatives assessment the lowest AEI value and cost, the ratio of B-C oil, light oil and LNG are 2.5%, 20%, 77.5%, respectively.

• Korean Journal of Remote Sensing
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• v.22 no.3
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• pp.183-197
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• 2006

Combinations of visible and near-infrared (NIR) bands in an image are widely used for estimating vegetation vigor and productivity. Using this approach to understand within-field grain crop variability could allow pre-harvest estimates of yield, and might enable mapping of yield variations without use of a combine yield monitor. The objective of this study was to estimate within-field variations in crop yield using vegetation indices derived from hyperspectral images. Hyperspectral images were acquired using an aerial sensor on multiple dates during the 2003 and 2004 cropping seasons for corn and soybean fields in central Missouri. Vegetation indices, including intensity normalized red (NR), intensity normalized green (NG), normalized difference vegetation index (NDVI), green NDVI (gNDVI), and soil-adjusted vegetation index (SAVI), were derived from the images using wavelengths from 440 nm to 850 nm, with bands selected using an iterative procedure. Accuracy of yield estimation models based on these vegetation indices was assessed by comparison with combine yield monitor data. In 2003, late-season NG provided the best estimation of both corn $(r^2\;=\;0.632)$ and soybean $(r^2\;=\;0.467)$ yields. Stepwise multiple linear regression using multiple hyperspectral bands was also used to estimate yield, and explained similar amounts of yield variation. Corn yield variability was better modeled than was soybean yield variability. Remote sensing was better able to estimate yields in the 2003 season when crop growth was limited by water availability, especially on drought-prone portions of the fields. In 2004, when timely rains during the growing season provided adequate moisture across entire fields and yield variability was less, remote sensing estimates of yield were much poorer $(r^2<0.3)$.

• Journal of Convergence for Information Technology
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• v.11 no.4
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• pp.122-129
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• 2021

As the total organic carbon (TOC) becomes a new water quality standard as an organic matter (OM) index for public sewage treatment facilities (PSTFs) in Korea from 2021, a comparison study needs to be conducted by examining the correlation between TOC and the existing OM indices (DOC, BOD5, CODMn, CODCr). 500 PSTFs were categorized by process configuration and capacity, and correlation between OM indices in influent and effluent was analyzed. The CODMn/TOC showed higher correlation than other OM indices. This results can be used to basic data for various research associated with TOC.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.2
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• pp.183-192
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• 2018

Applicability of corrosion inhibitor was evaluated using pilot scale water distribution pipe simulator. Calcium hydroxide was used as corrosion inhibitor and the corrosion indices of the water were investigated. Corrosion indices, Langelier saturation index (LI) increased by 0.8 and calcium carbonate precipitation potential (CCPP) increased by 9.8 mg/L. This indicated that corrosivity of water decreased by corrosion inhibitor and the effects lasted for 18 days. Optimum calcium hydroxide dose was found to be 3~5 mg/L for corrosion inhibition. We suggest that monitoring of CCPP as well as LI need to be conducted to control corrosivity of water.

• Journal of Korean Society on Water Environment
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• v.30 no.6
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• pp.612-621
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• 2014

Physicochemical factors and the phytoplankton communities in the downstream area of Namhan-River were investigated from June 2012 to November 2013. We also assessed water quality using biological water quality indices. Total nitrogen was 2.4 mg/L, total phosphorus was 0.04 mg/L, and biological oxygen demand was 1.1 mg/L. This resulted in a level 2 (Ib, good) water quality rating. A total of 259 phytoplankton taxa were classified, consisting of 26 families, two subfamilies, 64 genera, 222 species, 32 varieties, and five formas. Bacillariophyceae dominated during a1l seasons and at all sites. The dominant species were Aulacoseira granulata, Cyclotella meneghiniana, C. stelligera, Melosira varians, Cocconeis placentula var. lineata, Nitzschia palea, N. amphibia, Cymbella minuta, and Achnanthes convergens. The diatom assemblage index for organic pollution values was level A-D, and TDI was level B-D. P-IBI at most sites was at the M (moderate) level, but TSI was at the E (eutrophic) level. Most indices dropped from upstream to downstream.

• The Korean Journal of Health Service Management
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• v.10 no.4
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• pp.61-73
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• 2016

Objectives : The aim of this study was to investigate the satisfaction determinants of rehabilitation care group inpatients in rehabilitation long-term care hospitals. Methods : A survey was conducted with 262 patients from 6 rehabilitation long-term care hospitals located in Busan Kyungnam. Data were collected from June 2016 to July 2016 with a structured questionnaire and analyzed with SPSS 23.0. Results : The significant factors affecting the overall satisfaction score were disease group and 5 quality indices of medical services(Medical service quality, Rehabilitation services quality, Hospital reputation, External physical environment, and Internal physical environment). Additionally, the significant factors affecting intention to revisit were age, disease group, length of hospital stay and the 5 quality indices of medical services. Conclusions : The results of this study indicate that rehabilitation long-term care hospitals should try to improve the overall satisfaction of inpatients, especially focusing on the internal physical environment and the quality of the rehabilitation services and medical services, which will lead to a high level of intention for patients to revisit.

• Journal of Korean Society of Forest Science
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• v.99 no.6
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• pp.777-784
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• 2010

The purpose of this study was to develop evaluation indices for forest landscape classification. The indices were chosen to enable forest managers to establish effective landscape management strategies through three times of focus group interviews and email survey with experts. The 13 landscape evaluation indices were finally divided into four categories. They were ecological health (degree of green naturality, degree of ecological naturality, disease and insect damage, crown vitality), aesthetic visual quality (naturalness, harmony, diversity, traditionality, aesthetic appreciation, rarity), and sensitivity (level of tourism/recreational use), interruptions (damaged land, artificial structures). The five-level was suggested for the forest landscape classification system.