機械学習技術の視点による通勤交通手段選択と自動車所有に関する研究

過去数十年の間に，世界は急速な都市化プロセスを経験し，人々の生活には自動車が急速に普及した。モータリゼーションは我々に経済発展の機会を与えると同時に，生活の質に影響を与える地球環境に負荷をかけている。都市の自己増殖は，自家用車の所有と使用の増加を引き起こす主要な理由である。旅行モードの選択，車両所有パターン，およびそれらの決定要因に対して影響力のあるメカニズムを理解することは，土地利用と交通計画上の政策決定に大いに役立つ。この課題は，グローバリゼーションの時代に持続可能な交通の発展を目指す途上国において，大いに注目されている。本研究では，多項ロジットモデル，ニューラルネットワーク，ランダムフォレストを用いて，プノンペン市における将来のインパクトレベルと車両所有パターンの予測を行った。交通手段選択に関して，本研究では，勾配ブースティングマシン，機械学習アルゴリズム，およびLIMEを適用して，インドネシアのジャカルタ市の大都市圏における複数交通手段によるトリップパターンとその決定要因を推定した。両方の分析は，国際協力機構（JICA）から提供された世帯インタビュー調査データを使用した。分析結果は，家計収入がプノンペンのモータリゼーションに影響を与える最も強力な変数であることを示した。合計旅行回数などの個々の旅行特性の補足，通勤目的で行われた移動回数と全体の移動距離は全て，分類子として効果的に作用した。ジャカルタ市におけるケーススタディにおいては，単一交通機関の旅行に影響を与える要因として旅行費用や移動時間といった限られた変数が選ばれる一方で，複数交通機関の旅行については幅広い変数の影響を受けていることが示された。さらに，機械学習アプローチによる予測においては，精度を予測するという点だけでなく，統計的アプローチと比較して不均衡なカテゴリを処理するという点でも優れていたことが認められた。特に，グラディエントブースティングマシンは，ビッグデータで課題を解決する際，優れた潜在能力があることが示された。これら二つの結果は，旅行行動分析の分野に関して機械学習技術を適用する優位性を示し，他の分析に関しても，機械学習技術が応用できる可能性を示唆している。In the last decades, the world has seen the rapid urbanization process with the boom of motorized vehicles. The motorization, on one hand, gives opportunities for economic development and on the other hand, it puts pressure on the environment that affects the quality of life. The self-proliferating of the city is identified as a major that causes the rise of private vehicle ownership and usage. Understanding the influential mechanism of the travel mode choice, vehicle ownership patterns, and their determinants will greatly help policymaking for land use and transportation. This issue has been paid even greater attention in developing countries that aspire to reach sustainable transportation development goals in the era of globalization.In this study, the Multinomial logit model, Neural Networks and Random Forest were applied to examine the features’ impact level and to also predict vehicle ownership patterns in Phnom Penh city. Regarding travel mode choice, this study introduces the application of Gradient Boosting Machine, a Machine Learning algorithm, and Local Interpretable Model-agnostic Explanations technique to investigate the multi-mode trip pattern and its determinants in the metropolitan area of Jakarta city, Indonesia. Both analyses used the household interview survey data provided by the Japan International Cooperation Agency (JICA). The results indicate that household income is the most powerful variable affecting motorization in Phnom Penh. Supplementation of individual trip characteristics such as total number of trips made, number of trips made for work purposes and overall travel distance all make effective contributions as classifiers. The results from the case study of Jakarta city show that there was a limit of features (travel cost, time, etc.) that affected the single-mode trip while the multi-mode travel was influenced by the wide range of variables. Furthermore, it is acknowledged that the machine-learning approach outperformed not only in terms of predicting accuracy but also in dealing with unbalanced categories when compared with the statistical approach. Especially, the Gradient Boosting Machine indicated the impressive potentiality in solving the subject with big data. This detection supplies the advantages of applying machine learning techniques in terms of, but not limited to, the field of travel behavior.室蘭工業大学 (Muroran Institute of Technology)博士（工学

A Robust Mobile Robot Navigation System using Neuro-Fuzzy Kalman Filtering and Optimal Fusion of Behavior-based Fuzzy Controllers

This study proposes a control system model for mobile robots navigating in unknown environments. The proposed model includes a neuro-fuzzy Extended Kalman Filter for localization task and a behaviorbased fuzzy multi-controller navigation module. The neuro-fuzzy EKF, used for estimating the robot’s position from sensor readings, is an enhanced EKF whose noise covariance matrix is progressively adjusted by a fuzzy neural network. The navigation module features a series of independently-executed fuzzy controllers, each deals with a specific navigation sub-task, or behavior, and a multi-objective optimizer to coordinate all behaviors. The membership functions of all fuzzy controllers play the roles of objective functions for the optimizer, which produces an overall Pareto-optimal control signal to drive the robot. A number of simulations and real-world experiments were conducted to evaluate the performance of this model

The Relationship between Real Earnings Management and Firm Performance: The Case of Energy Firms in Vietnam

This investigation analyses the influence of real activities earnings management on firm performance of the energy listed firms on Vietnam's stock market. Our data collection constitutes 29 energy companies on Vietnam stock markets (HNX and HOSE) in the period from 2010 to 2016. We used regression analysis in accordance with panel data, namely fixed effects model and random effects model. The results determine that real activity earnings management positively impacts on firm performance. This implies that increasing current sales activities will have a positive impact on current earnings. However, this may be pernicious to the company in the future. There is a positive association between firm size, cash from operating activities, growth opportunities and firm performance while firm leverage and tangible asset have a negative association. Research results are significant for regulators and investors in emerging markets. Keywords: real earnings management, firm performance, energy firms, Vietnam. JEL Classifications: M41; G32 DOI: https://doi.org/10.32479/ijeep.746

Collaboration Between Social Workers and Educational Forces in Schools: Advantages, Objectives, Content, and Form

Cooperation between social workers and educational forces in high schools is viewed as a two-way cooperative effort to assist learners needing intervention. Intervention, emergency support for teachers or students needing intervention or assistance; Organize events to promote student development, community integration, and assistance for teachers and parents in need. The evaluation criteria for the cooperation between social workers and educational forces are based on four coordination components. Includes four scales evaluating the advantages, objectives, contents, and form of cooperation between high school social work personnel and educational agencies. A review of the cooperation between social work personnel and educational forces in high schools is gaining interest, although no research has been conducted on this topic. According to research findings, coordination between social work personnel and educational forces in high schools has been formed, albeit to a low and inconsistent degree across activities. The institution must perfect the organizational structure of its operations, management, and social work divisions. Furthermore, when coordinating with educational forces, social work personnel must emphasize the benefits of cooperation with educational forces. In addition, social workers must be adaptable between forms and activities according to the conditions and nature of their work.Ho Chi Minh City University CS.2021.19.4

Comparing smell identification ability among different motor subtypes of Parkinson’s disease using the Vietnamese Smell Identification Test and the Brief Smell Identification Test

IntroductionOlfactory dysfunction is one of the most common non-motor symptoms of Parkinson's disease (PD). The association between smell identification ability and motor subtypes of PD is not uniform in previous studies. This study aimed to compare the odor identification ability among different motor subtypes of PD in Vietnamese participants.MethodsPatients who were diagnosed with PD according to the International Parkinson's Disease and Movement Disorder Society 2015 Diagnostic Criteria and had normal cognitive function were recruited. Participants were divided into akinetic-rigid (AR), tremor-dominant (TD), and mixed (MX) motor subgroups using the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) score. Olfactory identification ability was evaluated using the Vietnamese Smell Identification Test (VSIT) and the Brief Smell Identification Test (BSIT). Cognitive status was assessed using the Mini-Mental State Examination (MMSE). Age, age at PD onset, disease duration, smell identification ability, and cognitive function were compared among the three PD motor subtypes.ResultsThe AR subgroup was the most common motor subtype (n = 164, 75.2 %), followed by TD (n = 39, 17.9 %), and MX (n = 15, 6.9 %) subtypes. Age, age at PD onset, sex, disease duration, and MMSE score were not significantly different between the three motor subgroups (all p > 0.05). The median (IQR) VSIT scores of AR, TD, and MX subgroups were 5.00 [4.00;7.00], 5.00 [3.50;7.00], and 5.00 [3.00;6.00], respectively. The median (IQR) BSIT scores of AR, TD, and MX subgroups were 6.00 [4.00;7.00], 5.00 [4.00;7.00], and 5.00 [4.50;7.00], respectively. The VSIT and the BSIT scores were not significantly different among the three motor subtypes (all p > 0.05).ConclusionSmell identification ability assessed in both the VSIT and BSIT did not differ across the three motor subtypes of PD

A prospective multi-center observational study of children hospitalized with diarrhea in Ho Chi Minh City, Vietnam.

We performed a prospective multicenter study to address the lack of data on the etiology, clinical and demographic features of hospitalized pediatric diarrhea in Ho Chi Minh City (HCMC), Vietnam. Over 2,000 (1,419 symptomatic and 609 non-diarrheal control) children were enrolled in three hospitals over a 1-year period in 2009-2010. Aiming to detect a panel of pathogens, we identified a known diarrheal pathogen in stool samples from 1,067/1,419 (75.2%) children with diarrhea and from 81/609 (13.3%) children without diarrhea. Rotavirus predominated in the symptomatic children (664/1,419; 46.8%), followed by norovirus (293/1,419; 20.6%). The bacterial pathogens Salmonella, Campylobacter, and Shigella were cumulatively isolated from 204/1,419 (14.4%) diarrheal children and exhibited extensive antimicrobial resistance, most notably to fluoroquinolones and third-generation cephalosporins. We suggest renewed efforts in generation and implementation of policies to control the sale and prescription of antimicrobials to curb bacterial resistance and advise consideration of a subsidized rotavirus vaccination policy to limit the morbidity due to diarrheal disease in Vietnam

Diagnostic value of vietnamese smell identification test in Parkinson's disease

IntroductionThe Vietnamese Smell Identification Test (VSIT) has been validated in determining olfactory dysfunction in the Vietnamese population; however, its value in diagnosing Parkinson's disease (PD) has not been established.MethodsThis case-control study was conducted at University Medical Center HCMC, Ho Chi Minh City, Vietnam. The study sample included non-demented PD patients and healthy controls (HC) who were gender- and age-matched. All participants were evaluated for odor identification ability using the VSIT and the Brief Smell Identification Test (BSIT).ResultsA total of 218 HCs and 218 PD patients participated in the study. The median VSIT and BSIT scores were significantly different between PD and HC groups (VSIT, 5 (3) vs. 9 (2), P < 0.0001; BSIT, 6 (3) vs 8 (2), P < 0.0001). Using the cut-off of <8 for correct answers out of 12 odorants, the VSIT had higher sensitivity (84.4%) and specificity (86.2%) than those of the BSIT (sensitivity of 81.7% and specificity of 69.3%) for the diagnosis of PD. The area under the curve (AUC) value was greater for the VSIT than for the BSIT (0.909 vs 0.818). The smell identification scores were not significantly correlated with disease duration, disease severity, or LEDD (all p > 0.05).ConclusionThe VSIT can be a valuable ancillary tool for supporting the diagnosis of PD in Vietnam. Olfactory dysfunction in PD was unrelated to the disease duration and severity. The VSIT can be applied to improve the accuracy of clinical PD diagnosis

Clinical implications of reduced susceptibility to fluoroquinolones in paediatric Shigella sonnei and Shigella flexneri infections.

OBJECTIVES: We aimed to quantify the impact of fluoroquinolone resistance on the clinical outcome of paediatric shigellosis patients treated with fluoroquinolones in southern Vietnam. Such information is important to inform therapeutic management for infections caused by this increasingly drug-resistant pathogen, responsible for high morbidity and mortality in young children globally. METHODS: Clinical information and bacterial isolates were derived from a randomized controlled trial comparing gatifloxacin with ciprofloxacin for the treatment of paediatric shigellosis. Time-kill experiments were performed to evaluate the impact of MIC on the in vitro growth of Shigella and Cox regression modelling was used to compare clinical outcome between treatments and Shigella species. RESULTS: Shigella flexneri patients treated with gatifloxacin had significantly worse outcomes than those treated with ciprofloxacin. However, the MICs of fluoroquinolones were not significantly associated with poorer outcome. The presence of S83L and A87T mutations in the gyrA gene significantly increased MICs of fluoroquinolones. Finally, elevated MICs and the presence of the qnrS gene allowed Shigella to replicate efficiently in vitro in high concentrations of ciprofloxacin. CONCLUSIONS: We found that below the CLSI breakpoint, there was no association between MIC and clinical outcome in paediatric shigellosis infections. However, S. flexneri patients had worse clinical outcomes when treated with gatifloxacin in this study regardless of MIC. Additionally, Shigella harbouring the qnrS gene are able to replicate efficiently in high concentrations of ciprofloxacin and we hypothesize that such strains possess a competitive advantage against fluoroquinolone-susceptible strains due to enhanced shedding and transmission

THE CURRENT CONDITIONS OF PROMOTING THE PHYSICAL EDUCATION AND SPORTS ACTIVITIES FOR STUDENTS AT VIETNAM NATIONAL UNIVERSITY, HO CHI MINH CITY

The purpose of the study was to have a comprehensive understanding of the existing conditions assured to give physical education (PE) programs to students at Vietnam National University, Ho Chi Minh City (VNUHCM). Through document synthesis, interviews, and statistical processing, the article gained a general evaluation of the current PE conditions according to the following aspects: facilities, administration, and curriculums. In terms of facilities, the total space for sports activities at VNUHCM is measured at 25,454m2, besides, the ratio of sports field area per student is 0.44m2/student. This indicates that VNUHCM’s students do not have enough space for their sports practice as standard. In terms of faculty, teachers at VNUHCM Sports Center are comprised 67.6% male, 88.2% at the age of thirty to fifty, and 100% holding postgraduate qualifications. In addition, 79.4% of the staff at the VNUHCM Sports Center graduated with PE specialized degrees, and 64.7% of them have less than five years of seniority. However, 68.8% of those who are currently delivering PE courses at this Center are visiting teachers. The statistic number reveals that the ratio of students per teacher at VNUHCM is 814.75 students/teacher, which reveals that the number of PE lecturers has not met the standard, and they have been in charge of a large teaching volume. In terms of curriculums, PE programs are conducted with 06 credits in total (90 periods), divided into 02 modules with 3 credits per each (45 periods). Students are allowed to choose their favorite PE content among 10 sports courses including football, volleyball, basketball, table tennis, tennis, badminton, martial arts, aerobics, swimming, and chess. The results indicate that VNUHCM’s students actively participate in sports training and competitions to advance their physical fitness.  Article visualizations

Perceived Audit Quality, Earnings Management and Cost of Debt Capital: Evidence from the Energy Listed Firms on Vietnam's Stock Market

This study examines the impact of perceived audit quality and accrual-based earnings management on cost of debt capital of the energy listed firms on Vietnam's stock market. Our data set includes 29 energy companies on Vietnam stock markets (HNX and HOSE) in the period from 2010 to 2016. We used FEM and REM estimator to test our hypotheses. The results confirm that there is no significant statistical association between accrual-based earnings management and cost of debt. There is a negative association between audit quality, firm size, return on assets and cost of debt while firm leverage and the tangible asset has a positive association. Moreover, global financial crisis has no statistically significant influence on the cost of debt capital. The research results have implications for regulators and investors about the stability of the economy in emerging markets. Keywords: cost of debt, earnings management, audit quality, energy enterprises, Vietnam. JEL Classifications: M42; G32 DOI: https://doi.org/10.32479/ijeep.699