Kochi University of Technology Academic Resource Repository

山田, 篤司

Japanese

What is Adler Psychology “Social Interest”?

獅々堀, 達哉

フローチャートおよび構造化チャートを用いたプログラミング授業支援システムの構築

髙田, 知裕

定量データを活用した聴診教育支援

YANG Yijiu

English

Immature Citrus Detection and Single Tree Leaf Number Estimation in Infrared Image

高知工科大学博士（学術）doctoral thesi

Alimo David Lagu Bernard

 
- 1 - 
 
氏 名（本籍） David Lagu Bernard Alimo（南スーダン共和国） 
学位の種類   博士（学術） 
学位記番号   甲第 409号 
学位授与年月日 令和５年９月 20日 
学位授与の要件 学位規則第４条第２項 
研究科・専攻名 工学研究科・基盤工学専攻 
学位論文題目  Coverage, Spectral, and Energy Efficiency Enhancement in Millimeter-wave 
Massive MIMO Systems Towards Future Wireless Networks  
（次世代ワイヤレスネットワークに向けたミリ波大規模 MIMO システムの収容効
率，スペクトル効率，エネルギー効率の強化） 
論文審査    （主査）高知工科大学  教授     濵村 昌則 
高知工科大学  教授     任 向実 
高知工科大学   教授     栗原 徹 
高知工科大学  教授     福本 昌弘 
高知工科大学  准教授    小林 弘和 
 
 
審 査 結 果 の 要 旨 
 
１.論文の評価 
 本論文ではレンズアンテナを用いたミリ波大規模アンテナシステムについて，移動通信の収容エリア
拡大・スペクトル効率の向上・エネルギー効率の向上等を目的とした研究の結果が述べられている．関
連する手法が大きく分けて３通り提案され，詳細な解析結果が示されている．特に以下の点の新規性・
有効性が評価された． 
 
 信号対雑音干渉比に基づき中継ユーザを選別する手法により，ネットワークの複雑性を抑制しつつ性
能を改善できることが示されている．同一ビーム内のユーザ間干渉を抑える手法により収容効率を向上
させられることや，異なるビーム間の干渉を抑える手法により収容エリアを拡大できることなどが示さ
れている． 
 比較的新しい技術であるレートスプリッティング多元接続（rate-splitting multiple access: RSMA)
と，直交ランダムプリコーディングの併用によりシステム全体の通信容量を表すサムレート等を改善で
きることが示されている．RSMAは空間分割多元接続に加えて直交・非直交の多元接続を包含する自由度
の高い新しい方式であり，それを含めた最適化問題を近似的に解く方法が示されている． 
 最近注目されるようになった Intelligent Reflecting Surface (IRS)と呼ばれる電波の反射方向を任
意に制御可能な反射板を用いて，見通しが確保できないユーザに対する通信性能を改善する手法が提案
されている．同一ビーム内のユーザ間干渉を抑えるために，複数の最適化アルゴリズムを組み合わせた
低複雑度のアンテナ選択法が示されている． 
 
 
 
２.審査の経過と結果 
（１）令和５年 6 月 28 日 ５名の審査委員のもと協議され、博士後期課程委員会で学位論文の受理
を決定した。 
（２）令和５年 8 月 21 日 公開論文審査発表会及び最終試験を実施した。 
（３）令和５年 9 月１日 博士後期課程委員会で学位授与を可とし、教育研究審議会で承認された。 


Coverage, Spectral, and Energy Efficiency Enhancement in Millimeter-wave Massive MIMO Systems Towards Future Wireless Networks

Van Tam, Nguyen

－1－ 
 
論 文 内 容 の 要 旨 
 
Construction labor productivity (CLP) is an important aspect of the construction industry. The 
construction sector, in many developing countries like Vietnam, is facing numerous problems. One of 
the big problems is poor labor productivity. To solve this problem, many studies have identified and 
classified factors affecting this aspect. However, the roles of autonomous motivation (AM) and work 
autonomy (WA) in CLP improvement has been ignored. This knowledge gap hampers further efforts to 
explore new CLP determinants that increase productivity. Accordingly, self-determination theory 
(SDT) is promising in terms of its ability to bridge this gap and explain how AM and WA can be 
generated by integrating reasonable leadership styles and basic psychological needs satisfaction 
(BPNS). Therefore, this project was designed to explore the roles of AM and WA in improving CLP 
based on SDT perspective. This project includes three studies as follows:  
The first study developed a novel model for assessing the effects of engaging leadership, three basic 
psychological satisfaction factors (i.e., autonomy, competence, and relatedness), and work motivation 
(i.e., autonomous motivation, controlled motivation and amotivation) on CLP. The structural equation 
modelling (SEM) results showed that, in addition to reinforcing the traditional view, which emphasized 
the role of controlled motivation (CM) in CLP improvement, this study revealed several interesting and 
valuable findings. First, the important role of AM in proving CLP was explored. Second, to improve AM 
and CLP, the satisfaction of competence and relatedness needs to be played a vital role. These findings 
provide a new perspective on both industry and academics with respect to how CLP can be enhanced, 
as well as how AM can be generated and maintained. Finally, the “negative legacy” of the construction 
industry was explored. This feature implied that the older and more experienced, but not necessarily 
skillful, workers perceived autonomy satisfaction as being achieved through selfish work, resulting in 
an obstacle to productivity improvement and the promotion or maintenance of work motivation. Selfish 
work is a novel factor that was first discovered in the construction domain. This study provides 
substantial practical recommendations for CLP improvement, such as enhancing autonomous 
motivation, promoting satisfaction with competence and relatedness, and reducing selfish work. 
Theoretically, this study expands and reinforces SDT knowledge by comprehensively illuminating 
leadership and psychological and motivational indicators in the construction context. 
In the second study, the author quantitatively measured the WA level of workers by adopting Relative 
Autonomy Index (RAI) and Aggregated Motivation Index (AMI) that was developed in this research. 
The results showed the different effects of two of these scoring protocols in measuring WA. Specifically, 
the RAI explains differences in WA between genders, while the AMI more precisely accounts for 
dissimilarities in WA on the basis of work experience. In addition, the author developed a new model by 
which to discover the function of WA in increasing CLP and determined the ways through which WA 
can be cultivated and maintained. The SEM was conducted to examine the effects of WA on CLP. The 
results indicated that WA positively and significantly contributed to CLP. Promoting WA required 
paying attention to the competence and relatedness satisfaction of the workers. Furthermore, latent 
and potentially extensive labor management-related problems were identified, namely, unsuccessful 
career development and the underutilization of experienced workers. Three meaningful policy 
recommendations were put forward to solve the aforementioned problems and improve CLP: the 
effective organization of crew members, the improvement of training, and the improvement of site 
amenities. This study expands theoretical knowledge by (1) developing and justifying the AMI as an 
auxiliary to conventional indices, (2) proposing five conditions necessary for optimal scoring in WA 
－2－ 
measurement and (3) developing a motivation matrix that identifies and distinguishes the attributes of 
different groups. In practical terms, the findings support the introduction of reasonable policies that 
advance the career development of workers, promote WA and improve CLP. These achievements, in 
turn, significantly advance effective and sustainable construction workforce management.  
The first study explored the ways of promoting work motivation through BPNS, in fact, however, many 
factors in addition to BPNS may affect work motivation of construction workers. Hence, the third study 
managed 35 factors constraining their work motivation in construction projects. This study differs from 
past studies in CLP research by investigating the severity level and occurrence frequency of barriers to 
work motivation in construction projects, and a more realistic ranking of these factors by adopting a 
risk mapping approach. The results indicated that the following barriers as the most significant factors 
constraining work motivation in construction projects: (1) payment delay, (2) lack of financial incentive 
schemes, (3) lack of professional training and advanced learning opportunities, (4) poor work condition, 
(5) unskilled workforce, and (6) work dissatisfaction.  
 
Keywords: autonomous motivation, work autonomy, construction labor productivity, self-determination 
theory, Vietnam. 


Improving construction labor productivity based on self-determination theory: A case study in Vietnam

多田, 直矢

遠赤外線カメラを用いたハウス内ピーマンの果実認識

沢田, 侑斗

CNT 生成プロセスにおける真空環境分析を用いたCNT 成長高さの再現性向上

藤原, 晴

セキュリティ対策行動を促す啓発手法の提案と評価

森田, 吉貴

Web ページへの SD 法印象評価におけるレイアウトとコンテンツ入替の影響

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