• Title/Summary/Keyword: problem analysis

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Seasonal Water Change Assessment at Mahanadi River, India using Multi-temporal Data in Google Earth Engine

  • Jena, Ratiranjan;Pradhan, Biswajeet;Jung, Hyung-Sup;Rai, Abhishek Kumar;Rizeei, Hossein Mojaddadi
    • Korean Journal of Remote Sensing
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    • v.36 no.1
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    • pp.1-13
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    • 2020
  • Seasonal changes in river water vary seasonally as well as locationally, and the assessment is essential. In this study, we used the recent technique of post-classification by using the Google earth engine (GEE) to map the seasonal changes in Mahanadi river of Odisha. However,some fixed problems results during the rainy season that affects the livelihood system of Cuttack such as flooding, drowning of children and waste material deposit. Therefore, this study conducted 1) to map and analyse the water density changes and 2) to analyse the seasonal variation of river water to resolve and prevent problem shortcomings. Our results showed that nine types of variation can be found in the Mahanadi River each year. The increase and decrease of intensity of surface water analysed, and it varies in between -130 to 70 ㎥/nf. The highest frequency change is 2900 Hz near Cuttack city. The pi diagram provides the percentage of seasonal variation that can be observed as permanent water (30%), new seasonal (28%), ephemeral (12%), permanent to seasonal (7%) and seasonal (10%). The analysis is helpful and effective to assess the seasonal variation that can provide a platform for the development of Cuttack city that lies in Mahanadi delta.

Principal Components Logistic Regression based on Robust Estimation (로버스트추정에 바탕을 둔 주성분로지스틱회귀)

  • Kim, Bu-Yong;Kahng, Myung-Wook;Jang, Hea-Won
    • The Korean Journal of Applied Statistics
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    • v.22 no.3
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    • pp.531-539
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    • 2009
  • Logistic regression is widely used as a datamining technique for the customer relationship management. The maximum likelihood estimator has highly inflated variance when multicollinearity exists among the regressors, and it is not robust against outliers. Thus we propose the robust principal components logistic regression to deal with both multicollinearity and outlier problem. A procedure is suggested for the selection of principal components, which is based on the condition index. When a condition index is larger than the cutoff value obtained from the model constructed on the basis of the conjoint analysis, the corresponding principal component is removed from the logistic model. In addition, we employ an algorithm for the robust estimation, which strives to dampen the effect of outliers by applying the appropriate weights and factors to the leverage points and vertical outliers identified by the V-mask type criterion. The Monte Carlo simulation results indicate that the proposed procedure yields higher rate of correct classification than the existing method.

Car-tire-related Crushing Injury of the Lower Leg in Children (자동차 바퀴에 의한 소아 아래다리의 압궤 손상)

  • Choi, JaeYeon;Jang, JaeHo;Woo, JaeHyuck;Park, WonBin;Kim, JinJoo;Hyun, SungYeol;Lee, Geun;Gwak, JeeHoon
    • Journal of Trauma and Injury
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    • v.26 no.3
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    • pp.175-182
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    • 2013
  • Purpose: Crushing injuries by car tires result from a combination of friction, shearing, and compression forces and the severity of injury is influenced by the acceleration. Because car-tire injuries of the lower leg in children are common these days but they have received little attention; thus, our purpose was to look closely into this problem. Methods: A retrospective analysis was conducted of data from children under 15 years old age who visited an emergency department because of a car-tire-related crushing injury to the lower leg in pedestrian traffic accident from January 2008 to September 2012. The patient's age, sex, site of injury, degree of injury, associated injuries, type of surgery, and complications were reviewed. Results: There were 39 children, the mean age was 8.0 years, and 71.8% were boys. The dorsal part of the leg was involved most frequently. According to the severity classification, 15 children were grade I, 6 were grade II, and 18 were grade III. Among 24 patients, 13 were treated with skin graft and 3 were treated using a sural flap. Twelve patients developed complications, such as hypertrophic scarring, contractures, and deformities with significant bone loss. Conclusion: Various degrees of skin or soft tissue defects were caused in children by car tires. In this study, patients were often also had tendon or bone damage. Proper and timely initial treatments are needed to reduce the incidence of infection, the number of operative procedures, and the hospital stay.

Signal Processing Technology for Rotating Machinery Fault Signal Diagnosis (회전기계 결함신호 진단을 위한 신호처리 기술 개발)

  • Ahn, Byung-Hyun;Kim, Yong-Hwi;Lee, Jong-Myeong;Lee, Jeong-Hoon;Choi, Byeong-Keun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.24 no.7
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    • pp.555-561
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    • 2014
  • Acoustic Emission technique is widely applied to develop the early fault detection system, and the problem about a signal processing method for AE signal is mainly focused on. In the signal processing method, envelope analysis is a useful method to evaluate the bearing problems and wavelet transform is a powerful method to detect faults occurred on rotating machinery. However, exact method for AE signal is not developed yet for the rotating machinery diagnosis. Therefore, in this paper two methods which are processed by Hilbert transform and DET for feature extraction. In addition, we evaluate the classification performance with varying the parameter from 2 to 15 for feature selection DET, 0.01 to 1.0 for the RBF kernel function of SVR, and the proposed algorithm achieved 94 % classification of averaged accuracy with the parameter of the RBF 0.08, 12 feature selection.

The effects of Oriental medicine treatment and the characteristics of MMPI profile on Vertigo Patients (어지럼증 환자(患者)의 MMPI 프로파일 특성과 한의학적(韓醫學的) 치료효과(治療效果))

  • Kim, Jin-Woo;Lee, Soon-E;Kim, Ja-Young;Kim, Tae-Heon;Lyu, Yeong-Su;Kang, Hyung-Won
    • Journal of Oriental Neuropsychiatry
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    • v.17 no.3
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    • pp.67-75
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    • 2006
  • This Study is attempted to analyze Minnesota Multiphasic Personality Inventory responses to Vertigo patients and remedial value of Oriental medicine treatment. Methods: 24 Vertigo patients and 28 control group were tested by MMPI and QSCCII. It is analyzed by cluster analysis, one-way ANOVA, chi-square test, t-test, Duncan method is used as ex-post test. Results and Conclusions: 1. The MMPI scores of Vertigo patients were elevated in Hs, Hy clinical scales, 1-3 profile type, it is profile of conversional neurosis. In this case body condition where the psychological problem will get conversion is a notable feature. 2. All of the profiles can be classified three types of profile. Group 1(33.3%) showed 1-3-2 profile type and elevated Pt. scale, suggesting mainly depressive neurosis in the department of neuropsychiatry. Group 2 (37.5%) showed a normal profile. Group 3(29.2%) showed 1-3 profile type it is profile of conversional neurosis. With this result it is indicated that 62.5% Vertigo patients are related to emotional difficulties. 3. There was to a remedial value for the Vertigo patients, before treating from VAS score 10.00 after treating at VAS score 4.13. From this study, we know the possibility the Oriental medicine register remedial value for the Vertigo patients.

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An Analysis of students' problem solving ability on the equivalent mathematics situations -Focused on equations, inequalities, and functions- (동일한 수학적 상황에서 문제해결 능력 분석 연구 -방정식.부등식과 함수를 중심으로-)

  • Park, Jeong Mi;Lee, Joong Kwoen
    • Journal of the Korean School Mathematics Society
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    • v.16 no.4
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    • pp.883-898
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    • 2013
  • The purpose of this study is to examine that high school students recognize mathematical situation when they are requested for changing identical mathematics situations into different situations. The results of the study are followings. First, percentage of correct answers to the questions of turning equal mathematical situation into function is higher than the one of turning equal mathematical situation into equation and inequality. As a result of individual interview for comprehensibility of the students on these relations, it is found that if degree goes up and there is different expressions of questionaries although mathematical situation is identical, it affects comprehensibility of the subjects. Second, we found that they cannot understand identical mathematics situations because they have trouble in drawing graph or applying to get the answer while many students understand a point of intersection on the graph as a correct answer. Third, As a result of individual interview for comprehensibility of the students on relation between equation, inequality and function, we found that students manage to get correct answer even without perfect comprehensibility on this relation.

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Distribution on the Alien Plants in the Gyeong-in Ara Waterway, Korea (경인 아라뱃길의 외래식물 분포 현황)

  • An, Ji-Hong;Kim, Jung-Hyun;Park, Hwan-Joon;Kim, Sun-Yu;Park, Sung-Ae
    • Journal of Korean Society on Water Environment
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    • v.33 no.3
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    • pp.291-301
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    • 2017
  • This study was carried out to investigate distribution on the alien plants in the Gyeong-in Ara Waterway. The alien plants were a total of 82 taxa: 17 families, 63 genera, 80 species, and 2 varieties. This number corresponds to 25.5% of alien plants identified in Korea. The proportion of alien plants in every year was increased from upstream to downstream. As the result of the analysis on vegetation stratification, bank of waterside was covered with artificial materials preventing existence of vegetation, and had step-type cross section. Floodplain was composed of waterfront area. An array of vegetation was not typical dispersion, and terrestrial and alien plants were dominated the Gyeong-in Ara Waterway. Evaluation of naturalness based on the vegetation stratification showed grade 3 or 4. In order to solve a problem, method and level of restoration should be decided based on the result of diagnostic assessment. Therefore, we need to restore the step-type cross section as pool type one. From waterside to bank in this waterway, we recommend to introduce natural plants by imitating reference species composition. Since, an invasion of alien plants is expected to be accelerated due to the continuous artificial disturbance, we recommend to quantitative investigation on the invasion of alien plants and monitoring on the change of distribution.

A Survey of Weeds Occurrence on Paddy Fields in Gyeongbuk Province in Korea (경북지역 논 잡초 발생분포 조사)

  • Kim, Sang Kuk;Kim, Hak Yoon
    • Weed & Turfgrass Science
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    • v.3 no.1
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    • pp.6-12
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    • 2014
  • The survey of weed occurrence was conducted to identify problem weed species in the paddy field. The 320 sites of the 13 regions in Gyeongbuk Province were investigated from June to July, 2013. In the whole region, 51 weed species were identified including 34 annuals and 17 perennials. The highest importance value of annual weed and perennial was dominant 88.4 and 48.7%, in Gumi region, respectively. The most dominant weed species in paddy fields of Gyeongbuk Province were Monochoria vaginalis var. plantaginea (10.80%), followed by Lemna paucicostata (10.74%), Bidens tripartite (8.77%), Echinochloa oryzoides (7.17%), and Scirpus juncoides (6.20%). The similarity of paddy weeds in 13 regions observed through TWINSPAN analysis was distinguished by Ludwigia prostrata, Scirpus juncoides, Lindernia dubia, Polygonum aviculare, and Alopecurus aequalis var. amurensis. The weed species, Ludwigia prostrata, was divided into the four regions, Gyeongju, Gumi(direct seeding cultivation), Youngcheon and Euiseong and ten regions, Gumi, Bonghwa, Sanju, Goryung, Youngdeog, Pohang, Sanju, Andong, Yecheon, and Cheongdo.

Steering System Design of Commercial Vehicle for Improving Pulling Phenomenon During Braking (상용차의 제동시 쏠림 개선을 위한 조향 연결점 설계)

  • Lee, Chang Hun;Lee, Dong Wook;Lee, Yong Su;Sohn, Jeong Hyun;Kim, Kwang Suk;Yoo, Wan Suk
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.3
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    • pp.379-385
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    • 2013
  • The tires, suspension type, and steering system can all cause pulling during braking. Among these, a drag link steering system and leaf-type suspension system are significant causes of vehicle pulling. In this study, the pulling problem is analyzed using the vehicle analysis program "ADAMS/CAR." The drag link and leaf spring behavior is analyzed to find the key reason for pulling. After this, the optimization program "Visual DOC" is used with "ADAMS/CAR" to find a steering link connection point to reduce pulling. After conducting this simulation, K&C (kinematic & compliance) test simulation with a modified connection point is conducted to determine whether the vehicle performance improves. Through a full braking simulation, it is verified that the pulling distance is reduced at braking.

Device-to-Device assisted user clustering for Multiple Access in MIMO WLAN

  • Hongyi, Zhao;Weimin, Wu;li, Lu;Yingzhuang, Liu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.7
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    • pp.2972-2991
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    • 2016
  • WLAN is the best choice in the place where complex network is hard to set up. Intelligent terminals are more and more assembled in some areas now. However, according to IEEE 802.11n/802.11ac, the access-point (AP) can only serve one user at a single frequency channel. The spectrum efficiency urgently needs to be improved. In theory, AP with multi-antenna can serve multiple users if these users do not interfere with each other. In this paper, we propose a user clustering scheme that could achieve multi-user selection through the mutual cooperation among users. We focus on two points, one is to achieve multi-user communication with multiple antennas technique at a single frequency channel, and the other one is to use a way of distributed users' collaboration to determine the multi-user selection for user clustering. Firstly, we use the CSMA/CA protocol to select the first user, and then we set this user as a source node using users' cooperation to search other proper users. With the help of the users' broadcast cooperation, we can search and select other appropriate user (while the number of access users is limited by the number of antennas in AP) to access AP with the first user simultaneously. In the network node searching, we propose a maximum degree energy routing searching algorithm, which uses the shortest time and traverses as many users as possible. We carried out the necessary analysis and simulation to prove the feasibility of the scheme. We hope this work may provide a new idea for the solution of the multiple access problem.