Earticle

Properties and comparison of multivariate CUSUM and EWMA charts for monitoring Σ of multivariate normal N(μ, Σ) process has considered. Comparison of the performances of the considered charts, the numerical values are obtained by simulation with 10,000 iteration in terms of ATS, ANSS and ANSW. We found that EWMA chart with small values of smoothing constant more effectively detects the process changes than with large smoothing constant. And we also found that CUSUM chart with small value of reference value is more effectively detecting the process change than with large reference value. If a process engineer has interest in detecting small amount of shift rather than large shift, he/she can be recommended to use small smoothing constant in EWMA chart and small reference value in CUSUM chart.

Objective To determine the optimal stimulation and recording site for infrapatellar branch of saphenous nerve (IPBSN) conduction studies by a cadaveric study, and to confirm that obtained location is practically applicable to healthy adults. Methods Twelve lower limbs from six cadavers were studied. We defined the optimal stimulation site as the point IPBSN exits the sartorius muscle and the distance or ratio were measured on the X- and Y-axis based on the line connecting the medial and lateral poles of the patella. We defined the optimal recording site as the point where the terminal branch met the line connecting inferior pole of patella and tibial tuberosity, and measured the distance from the inferior pole. Also, nerve conduction studies were performed with obtained location in healthy adults. Results In optimal stimulation site, the mean value of X-coordinate was 55.50±6.10 mm, and the ratio of the Y-coordinate to the thigh length was 25.53%±5.40%. The optimal recording site was located 15.92±1.83 mm below the inferior pole of patella. In our sensory nerve conduction studies through this location, mean peak latency was 4.11±0.30 ms and mean amplitude was 4.16±1.49 mV. Conclusion The optimal stimulation site was located 5.0?6.0 cm medial to medial pole of the patella and 25% of thigh length proximal to the X-axis. The optimal recording site was located 1.5?2.0 cm below inferior pole of patella. We have also confirmed that this location is clinically applicable.

Objective To investigate the reference value for cross sectional area (CSA) of the fibular nerve in Koreans. Method One musculoskeletal radiologist and one physiatrist performed fibular nerve ultrasonography (US) on 60 lower extremities of 30 asymptomatic Korean volunteers (16 males, 14 females). The mean age was 46.6 years (range: 21-75 years). We measured CSA of the fibular nerve at three sites: proximal portion (PP) at the bifurcation, mid-portion (MP), and an area just above the fibular head (FH). In addition, the fibular nerves of 7 lower extremities from 4 cadavers were cut from the fibular head to the proximal portion and divided into three sections (PP, MP, FH). They were subsequently fixed with 10% neutral buffered formalin and perpendicularly excised to 2 mm thickness. They were photographed by an operating microscope and CSA was measured. Using the Kruskal-Wallis test, measurements obtained from US images were compared between asymptomatic volunteers with a significance level of 0.05. Results In asymptomatic volunteers, the CSA of the three portions were PP: 13.8±1.2 mm2, MP: 11.1±1.0 mm2, FH: 10.9±0.6 mm2. The fibular nerves were well visualized with clear borders by US. In cadavers, the CSA of three portions were PP: 20.3±10.3 mm2, MP: 16.7±8.6 mm2, FH: 14.4±8.9 mm2. There was no significant difference between the three portions in asymptomatic volunteers and cadavers (p＞0.05). Conclusion In normal Korean adults, the area of fibular nerve at the fibular head is 10.9±0.6 mm2. Ultrasonographic evaluation of the fibular nerve can be helpful in diagnosing fibular nerve lesions.

This study was performed to increase the accuracy of genomic estimated breeding value (GEBV) predictions for domestic pigs using single-breed and admixed reference populations (single-breed of Berkshire pigs [BS] with cross breed of Korean native pigs and Landrace pigs [CB]). The principal component analysis (PCA), linkage disequilibrium (LD), and genome- wide association study (GWAS) were performed to analyze the population structure prior to genomic prediction. Reference and test population data sets were randomly sampled 10 times each and precision accuracy was analyzed according to the size of the reference population (100, 200, 300, or 400 animals). For the BS population, prediction accuracy was higher for all economically important traits with larger reference population size. Prediction accuracy was ranged from ?0.05 to 0.003, for all traits except carcass weight (CWT), when CB was used as the reference population and BS as the test. The accuracy of CB for backfat thickness (BF) and shear force (SF) using admixed population as reference increased with reference population size, while the results for CWT and muscle pH at 24 hours after slaughter (pH) were equivocal with respect to the relationship between accuracy and reference population size, although overall accuracy was similar to that using the BS as the reference.

Objectives: To establish the reference range of latency values in pediatric patients according to their age. Methods: Visual evoked potential was performed on children between age 0 and 10, diagnosed with unilateral amblyopia at GangNam Severance Hospital between January 2005 and December 2008. Latency values for N1, P1, N2, P2, N3 were measured for the intact and the amblyopian eye. Results: For the intact eye the mean values of latency of were N1=31.6 ms, P1=50.8 ms, N2=80.0 ms, P2=113.3 ms, N3=160.3 ms and for the amblyopian eye they were N1=35.4 ms, P1=56.1 ms, N2=81.1 ms, P2=113.8 ms, N3=160.8 ms. There were no significant differences between the intact eye and the amblyopian eye. Compared to the normal values in adults, the mean values of latency was shorter for N1 and P1, and longer for N2, P2, and N3. These differences were statistically significant. Conclusion: This study showed that reference values of latency in visual evoked potential were different in children compared to the values in adults.

본 연구에서는 소비자들이 해당 상품에 대해 충분한 정보와 경험을 가지지 못하며 밀접한 대체재를 정의하기 어려운 상품을 대상으로 한 가치평가 조사에서 지불의사가격과 준거가격 개념의 질문이 어떤 차이를 발생시키는지 및 외부준거가격의 제시 여부가 미치는 영향을 분석한다. 준거가격은 공정성의 개념을 통해 소비자들의 구매의사결정에 영향을 미칠 수 있다. 반면 지불의사가격은 실제 가격과 비교되어 순효용(획득효용)을 결정한다. 따라서 이 두 가지 개념은 각기 중요한 의미를 가지며, 가격 의사결정에서 보완적으로 사용되어야 할 개념이다. 또한 과거 외부준거가격의 논의나 기준값(Anchoring), 프레이밍 등의 이슈를 고려할 때 외부준거가격의 제시 여부는 조사의 결과에 지대한 영향을 미칠 수 있다. 본 논문에서는 준거가격 조사의 경우 외부준거가격의 제시가 바람직한 반면 지불의사가격의 조사에서는 외부준거가격을 제시하지 않는 것이 바람직하다고 주장한다. 또한 5개의 가설을 제시하고 이를 검증하기 위해 하계유니버시아드대회에 대한 가격산정을 위한 설문조사 자료 및 추가적인 설문을 분석하였다. 분석 결과 외부준거가격을 제시하지 않고 조사된 지불의사가격은 외부준거가격을 제시하여 조사한 준거가격 대비 낮게 나타나며, 지불의사가격에서 변동계수 값이 더 크게 나타날 것이라는 가설이 지지되었다. 이러한 결과는 단순한 직접질문법의 조사결과에서도 질문의 방식에 따라 그 결과가 크게 다르게 나타날 수 있음을 보이는 것으로 조사방식의 설계의 중요성을 보여주는 것이다. 한편 외부준거가격을 동일하게 제시할 경우 지불의사가격과 준거가격 조사결과가 통계적으로 유의한 차이를 보이지 않았다. 또한 외부준거가격을 동일하게 제시하지 않은 경우 역시 두 가지 조사결과가 통계적으로 유의한 차이를 보이지 않았다. 반면 외부준거가격의 제시 여부에 따라 두 가지 조사방식에서 모두 뚜렷한 평균값의 차이를 보였다. 이는 가치평가의 조사에서 질문의 어의적 차이(얼마면 구입을 포기 vs. 적당한 가격) 대비 외부준거가격의 제시여부가 지대한 영향을 미침을 보이는 것이다. 마지막으로 지불의사가격과 준거가격 조사결과를 종속변수로, 개인의 특성변수들을 독립변수로 보아 회귀분석을 진행한 결과 회귀식의 결정계수가 전반적으로 낮게 나타났다. 준거가격의 경우 개념적으로 개인의 특성보다는 외부준거가격에 주로 영향을 받으므로 이러한 결과가 자연스럽다. 반면 지불의사가격은 개인의 특성을 반영해야 한다는 점에서 의외의 결과라고 할 수 있다. 하나의 설명은 지불의사가격은 동일 수준의 효용을 줄 것으로 판단되는 상품의 가격에 크게 의존하나 이를 회귀식에 반영치 못한 것이 원인이라는 것이다. 그러나 정확한 답변을 위한 유인의 제공과 답변에 대해 충분히 숙고할 수 있는 시간과 자료의 제공이 뒷받침되지 않은 경우 조사결과의 신뢰성이 담보되지 않을 수 있다는 가설도 가능하며, 이에 대한 추가적인 연구가 필요하다.

In eliciting customers' value, two kind of concepts can be used; willingness-to-pay and reference price. The two concepts affect on purchase decision complementarily. Hence, the survey about each of those concepts can be meaningful to marketers. On the other hand, considering the previous studies of external reference price, anchoring, and framing, whether external reference prices are offered or not can affect much on the result of the survey. With this background, this study analyzes the effect of difference in question (willingness-to-pay vs. reference price) and the effect of external reference price, considering products about which consumers do not have sufficient information and of which close substitutes are hard to be defined. For the analysis, data from a survey which was carried out for determining the level of price of summer universiade tickets were used. The result of analysis showed that the value of willingness-to-pay without showing the external reference price is lower than that of reference price with the external reference price, and that the coefficient of variation is lower in reference price with the external reference price. This shows that, even in simple open-end question method, the specific way of questions may result in big difference and emphasizes the importance of design of survey. On the other hand, when the external reference prices are offered in both of the questions, the results of willingness-to-pay and reference price become very similar. When the external reference prices are not offered, the two results also become similar. This means that whether or not showing the price of substitute products have dominant effect rather than the semantic difference of questions.

Our study aimed to identify age-related changes in knee proprioception to provide reference values for weight-bearing (WB) and non-weight-bearing (NWB) conditions and to identify factors (age, WB condition, dominance, and sex) that can affect knee proprioception.A total of 84 healthy adult men and women were recruited. Active knee joint position sense (JPS) was measured using a digital inclinometer for knee proprioception. The participants performed the required movements actively, with verbal feedback from the examiner, slowly moving to the target angles (30° and 50°) and maintaining them for 5?s before returning to the starting position. Afterward, without assistance from the examiner, the participants actively moved back to the same angle, and the examiner confirmed the angles. This procedure was repeated twice for each target angle, and the average values were used as the data. The participants were barefoot, wearing shorts, and closed their eyes while the measurements were obtained. The measurements were first obtained on the dominant side under the NWB conditions. When a change in posture was needed during the measurement, the participants sat in a resting position for 2?min.Except for age, all other factors (WB condition, dominance, sex) were not statistically significant. Age showed a significant difference in knee JPS, except for the non-dominant side at 30° and the dominant side at 50° in the NWB condition.This study indicates that the WB condition, dominant side, and sex need not be considered when measuring and assessing knee JPS. Age shows a negative correlation with knee joint position sense, and the reference values presented in this study can be used as objective target values during the rehabilitation process.

A single outlier can influence on the least squares estimators and can invalidate analysis based on these estimators. The Cook's statistic has been introduced to measure influence of individual data point on parameter estimation and the quantile of the F distribution is recommended as a reference value. but in practice subjective judgement is applied in the choice of appropriate quantile. A simple reference value is introduced in this paper which is developed by approximating conditional quantities of Cook's measure. The performance of the proposed criterion is evaluated through analysis of real data set.

반도체나 석유화학 공정과 같이 프로세스 중심의 장치 산업에서는 흔히 관측된 자료들 사이에 자기상관(Autocorrelation)이 존재하는데, 이러한 공정에 기존의 SPC(Statistical process control)를 적용하는 경우 공정의 평균 변화를 효과적으로 검출하지 못하는 문제가 발생할 수 있다. 본 논문에서는 특정 시계열 모형을 따르는 공정자료에 일정한 크기의 평균 변화가 발생할 때, 잔차는 시간의 흐름에 따라 그 평균이 달라지게 되는데, ARMA(1,1) 과정을 중심으로 평균의 변화 패턴을 소개하고, 이 결과를 바탕으로 공정의 작은 평균 변화를 검출할 수 있는 CUSUM(Cumulative sum) 관리도의 공정 자료가 갖는 시계열 모형의 형태와 관심 있는 공정 평균 변화의 폭을 고려하여 CUSUM 관리도의 설계 과정에서 필요한 참고값이 적절히 선택되어 사용되어야 함을 모의실험을 통해 확인하였다.

Most process date such as semiconductor and petrochemical processes, autocorrelation often exists between observed data, but when the existing SPC(Statistical process control) is applied to these processes, it is not possible to effectively detect the average change of the process. In this paper, when the average change of a certain size occurs in the process data following a specific time series model, the average of the residuals changes according to the passage of time, and the change pattern of the average is introduced around the ARMA(1,1) process. Based on this result, the reference value required in the design process of the CUSUM (Cumulative sum) control chart is appropriately considered by considering the type of the time series model of the process data of the CUSUM control chart that can detect small mean changes in the process and the width of the process mean change of interest. It was confirmed through simulation that it should be selected and used.

Purpose: Prolactin in the blood is separated into three types, and over 90% of prolactin presents as a double monomer (23 KDa). Rarely, it can exist in the size of big prolactin (150 KDa), which is called macroprolactin and is known as an autoantibody complex. When macroprolactin accounts for more than 60% of prolactin in the blood, it is called macroprolactinemia. The presence of such macroprolactin was first reported in a patient with hyperprolactinemia but without typical symptoms. Macroprolactinemia is emerging as an important cause of idiopathic hyperprolactinemia. The polyethylene glycol (PEG) precipitation method using the property of precipitating large-molecular-weight proteins is simple and recently has been widely used as a screening test. The results are in good agreement with the results of gel chromatography. The purpose of this study was to confirm the measurement method and reference value verification of monomeric prolactin in blood prolactin using the PEG precipitation method. Materials and Methods: For 40 examinees who visited the Gangnam Center of Seoul National University Hospital in 2021, the prolactin level was verified using radioimmunoassay (RIA). For macroprolactinemia PEG precipitation method, 25% PEG (molecular weight 6000kDa) solution and serum were mixed in equal amounts in a test tube, then left at room temperature for 20 minutes and centrifuged at 4℃ for 30 minutes (1500g). The prolactin level was measured in the supernatant. Results : After confirming that more than 90% of the 40 tested samples within the reference range <25 ng/mL, the same value as the reference value for prolactin was applied. Since the concentration of monomeric prolactin in serum from which macroprolactin has been removed from blood is diluted 1:1 with PEG, our laboratory is currently reporting the result by multiplying the result by a dilution factor of 2. Conclusion: Radioimmunoassay using PEG precipitation method using the property of precipitating large molecular weight proteins is simple and effective for quantitative measurement of monomeric prolactin in blood prolactin.

A mobile platform business is characterized by a value network in which stakeholders collaborate to create value centered around a mobile platform. This value network is viewed as an ecosystem because its structure is re-organized to the dynamic, changing relationships among the stakeholders. By using the e3-value, which is an ontological modeling approach, this study proposes a reference model for examining this value architecture of mobile platform businesses. In the proposed reference model, a mobile platform business is viewed as a structure for resource exchange among actors for value co-creation. In this study, this model is further adapted to real business cases to identify how mobile platform business varies in dynamic business contexts. The results provide guidelines for the development of a business model for mobile platform business, and will be applicable to make policy strategies for establishing a collaboration network in different innovation contexts including industrial and regional innovations.

Background: The accurate measurement of α-fetoprotein (AFP) is critical for clinical diagnosis. However, different AFP immunoassays may yield different results. Appropriate AFP reference materials (RMs) were selected and assigned accurate values for applications with external quality assessment (EQA) programs to standardize AFP measurements. Methods: Forty individual clinical samples and six different concentrations of candidate RMs (Can-RMs, L1?L6) were prepared by the Beijing Center for Clinical Laboratories. The Can-RMs were assigned target values by performing five immunoassays, using WHO International Standard 72/225 as a calibrator, and sent to 45 clinical laboratories in Beijing for AFP measurements. The commutability of all RMs was assessed based on CLSI and the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) approaches. Analytical performance was assessed for compliance based on accuracy (total error, TE), trueness (bias), and precision (CV). Results: The Can-RMs were commutable for all immunoassays using the CLSI approach and for 6 of 10 assay combinations using the IFCC approach. RMs diluted in WHO RM 72/225 were commutable among all assays with the CLSI approach, except for serum matrix (Autolumo vs. Roche analyzer) and diluted water matrix (Abbott vs. Roche/Mindray analyzer), whereas some inconclusive and non-commutable results were found using the IFCC approach. The average pass rates based on the TE, bias, and CV were 91%, 81%, and 95%, respectively. Conclusions: The commutability of the RMs differed between both evaluation approaches. The Can-RMs exhibited good commutability with the CLSI approach, suggesting their suitability for use with that approach as commutable EQA materials with assigned values and for monitoring the performance of AFP measurements.

This study was performed to increase the accuracy of genomic estimated breeding value (GEBV) predictions for domestic pigs using single-breed and admixed reference populations (single-breed of Berkshire pigs [BS] with cross breed of Korean native pigs and Landrace pigs [CB]). The principal component analysis (PCA), linkage disequilibrium (LD), and genome-wide association study (GWAS) were performed to analyze the population structure prior to genomic prediction. Reference and test population data sets were randomly sampled 10 times each and precision accuracy was analyzed according to the size of the reference population (100, 200, 300, or 400 animals). For the BS population, prediction accuracy was higher for all economically important traits with larger reference population size. Prediction accuracy was ranged from -0.05 to 0.003, for all traits except carcass weight (CWT), when CB was used as the reference population and BS as the test. The accuracy of CB for backfat thickness (BF) and shear force (SF) using admixed population as reference increased with reference population size, while the results for CWT and muscle pH at 24 hours after slaughter (pH) were equivocal with respect to the relationship between accuracy and reference population size, although overall accuracy was similar to that using the BS as the reference.

Shot change detection is an important technique for effective management of video data, so detection scheme requires adaptive detection techniques to be used actually in various video. In this paper, we propose an adaptive shot change detection algorithm using the mean of feature value on variable reference blocks. Our algorithm determines shot change detection by defining adaptive threshold values with the feature value extracted from video frames and comparing the feature value and the threshold value. We obtained better detection ratio than the conventional methods maximally by 15% in the experiment with the same test sequence. We also had good detection ratio for other several methods of feature extraction and could see real-time operation of shot change detection in the hardware platform with low performance was possible by implementing it in TVUS model of HOMECAST Company. Thus, our algorithm in the paper can be useful in PMP or other portable players.

Objectives : The aim of this study was to examine the reference value of biomarker serum amyloid p (SAP) to diagnose blood stasis objectively. Methods : Pubmed-Medline, Cochrane library, EMBASE were searched using the key words 'SAP' and 'serum amyloid p' in June 2018. Original articles of human adults that published in English, studies that recruited from the clinical research settings or well defined population based cohorts were only included. Results : A total of 12 studies were selected to extract the reference value of SAP. It was between 8.5 ng/mL (0.0085 mg/L) to 57.5 mg/L. Although the disease varied, most of them showed elevated SAP levels in the disease group (1.1-1.5 times). Conclusions : This study is meaningful in that it summarizes the results of previous researches of SAP, which has the potential to be diagnostic index of blood stasis.

This paper adopts Liu Xie(劉勰)’s viewpoint in his masterpiece Wenxindiaolong(≪文心雕龍≫) as a reference for instruction of Chinese writing teaching in college. It explores various aspects in terms of the selection of model essays, the explanation of exercises in a textbook, the introduction of authors, the cultivation of literary sentiment, the analysis of writing skills, the appreciation of writing styles, the emulation of specific writing methods and the guide to extra readings. Based on the above aspects, we hope to improve the effectiveness of Chinese writing teaching in college.

본 연구를 통해 항 GAD 항체검사에서 뇌척수액에 대한 정상치 범위를 추정하였다. 본원에서 211명을 대상으로 혈청과 뇌척수액에 대한 항 GAD 항체검사를 함께 의뢰받은 환자 데이터를 분석해 본 결과 혈청은 1.0 U/mL 이상의 값을 가진 환자가 약 5%를 차지하였고. 뇌척수액의 경우에는 1.0 U/mL이상의 값을 가진 환자는 약 98% 이상을 차지하였다. 혈청의 참고치 (1.0 U/mL 이상 양성)를 뇌척수액에 적용했을 경우에는 대부분의 환자들이 강직증후군 및 간질을 진단 받게 된다. 이에 혈청과 뇌척수액의 참고치를 병용해서 사용하는 것은 부적합하다고 판단하였고 뇌척수액에 대한 참고치를 본원에서 자체적으로 설정하고자 하였다. 실험 대상으로는 정상인의 뇌척수액을 채취하는 데는 어려움이 있어 이와 가장 유사한 생리식염수를 음성대조군으로 선정하였다. 총 70개의 생리식염수를 검사한 결과 Mean값이 1.97 U/mL, SD 값이 0.72 U/mL가 나왔다. 이 값들에 Hoffmann법으로 Mean값에서 ${\pm}2SD$를 정상범위로 하여 0.54 U/mL ~ 3.40 U/mL로 Expected reference range를 설정할 수 있었다. 본 실험에서 아쉬운 점은 참고치 설정에 있어 정상인의 뇌척수액으로 검사가 이루어지지 못한 부분이다. 앞으로 정상인의 뇌척수액으로 참고치 설정을 할 수 있다면 보다 더 정확하게 임상적으로 적용할 수 있을 것이라 생각 된다.

Purpose Anti-Glutamic acid decarboxylase antibody test (GAD Ab) has been used as a predictor of type 1 diabetes. GAD Ab has also been shown to be highly potent in cerebrospinal fluid (CSF) of patients with suspected diabetic peripheral neuropathy. Recently, it has been known that clinical significance of GAD Ab using CSF is useful for the neurological disorders. However, the reference value of anti-GAD Ab has been provided only for serum. In this experiment, we estimated the reference value of anti-GAD antibody for CSF in neurological patients. Materials and Methods A total of 211 neurological patients were enrolled. Serum and CSF were analyzed by radioimmunoassay (RIA) using commercial RIA anti-GAD Ab kit (RSR, London, United Kingdom). Normal saline was used as the normal CSF control because CSF is most similar to 0.9% normal saline. Results The mean value of normal CSF control was 1.97 U/mL, and two standard deviations (2SD) was 1.44 U/mL. Based on this data, the expected reference range of CSF could be estimated from 0.54 U/mL to 3.40 U/mL Conclusion The reference range of normal CSF control using normal saline obtained with Hoffmann's method. However, there will be a need to validate the CSF reference values using human normal CSF.