DSpace Collection:
http://hdl.handle.net/2115/20066
2024-03-29T14:56:32ZIs Japanese Internship for the Purpose of Education or Recruitment?: A Study of its Historical Background, and Recent Changes and Future Challenges
http://hdl.handle.net/2115/87687
Title: Is Japanese Internship for the Purpose of Education or Recruitment?: A Study of its Historical Background, and Recent Changes and Future Challenges
Authors: Jun KAMENO2022-12-31T15:00:00ZJun KAMENOProbing the minimal U(1)(X) model at future electron positron colliders via fermion pair-production channels
http://hdl.handle.net/2115/86674
Title: Probing the minimal U(1)(X) model at future electron positron colliders via fermion pair-production channels
Authors: Das, Arindam; Dev, P. S. Bhupal; Hosotani, Yutaka; Mandal, Sanjoy
Abstract: The minimal U(1)(X) extension of the Standard Model (SM) is a well-motivated new physics scenario, where anomaly cancellation dictates new neutral gauge boson (Z') couplings with the SM fermions in terms of the U(1)(X) charges of the new scalar fields. We investigate the SM charged fermion pair-production process for different values of these U(1)(X) charges at future e(-)e(+) colliders: e(+)e(-) -> f (f) over bar Apart from the standard gamma and Z-mediated processes, this model features additional s-channel (or both s and t-channel when f = e(-)) Z' exchange which interferes with the SM processes. We first estimate the bounds on the U(1)(X) coupling (g') and the Z' mass (M-Z') considering the latest dilepton and dijet constraints from the heavy resonance searches at the LHC. Then using the allowed values of g', we study the angular distributions, forward-backward (A(FB)), left-right (A(LB)), and left-right forward-backward (A(LR-FB)) asymmetries of the final states. We fmd that these observables can show substantial deviations from the SM results in the U(1)(X) model, thus providing a powerful probe of the multi-TeV Z' bosons at future e(+)e(-) colliders.2022-06-20T15:00:00ZDas, ArindamDev, P. S. BhupalHosotani, YutakaMandal, SanjoyThe minimal U(1)(X) extension of the Standard Model (SM) is a well-motivated new physics scenario, where anomaly cancellation dictates new neutral gauge boson (Z') couplings with the SM fermions in terms of the U(1)(X) charges of the new scalar fields. We investigate the SM charged fermion pair-production process for different values of these U(1)(X) charges at future e(-)e(+) colliders: e(+)e(-) -> f (f) over bar Apart from the standard gamma and Z-mediated processes, this model features additional s-channel (or both s and t-channel when f = e(-)) Z' exchange which interferes with the SM processes. We first estimate the bounds on the U(1)(X) coupling (g') and the Z' mass (M-Z') considering the latest dilepton and dijet constraints from the heavy resonance searches at the LHC. Then using the allowed values of g', we study the angular distributions, forward-backward (A(FB)), left-right (A(LB)), and left-right forward-backward (A(LR-FB)) asymmetries of the final states. We fmd that these observables can show substantial deviations from the SM results in the U(1)(X) model, thus providing a powerful probe of the multi-TeV Z' bosons at future e(+)e(-) colliders.Two-component scalar and fermionic dark matter candidates in a generic U(1)(X) model
http://hdl.handle.net/2115/86631
Title: Two-component scalar and fermionic dark matter candidates in a generic U(1)(X) model
Authors: Das, Arindam; Gola, Shivam; Mandal, Sanjoy; Sinha, Nita
Abstract: We consider a U(1)(X) (R) Z(2) (R) Z(2)' extension of the Standard Model (SM), where the U(1)(X) charge of an SM field is given by a linear combination of its hypercharge and B-L number. Apart from the SM particle content, the model contains three right-handed neutrinos (RHNs) N-R(i) and two scalars Phi, chi, all singlets under the SM gauge group but charged under U(1)(X) gauge group. Two of these additional fields, fermion N-R(3) is odd under Z(2) and scalar chi is odd under Z(2)' symmetry. Thus both chi and N-R(3) contribute to the observed dark matter relic density, leading to two-component dark matter candidates. We study in detail its dark matter properties such as relic density and direct detection taking into account the constraints coming from collider studies. We find that in our model, there can be possible annihilation of one Dark Matter (DM) into the other, which may potentially alter the relic density in a significant way. (C) 2022 The Author(s). Published by Elsevier B.V.2022-05-02T15:00:00ZDas, ArindamGola, ShivamMandal, SanjoySinha, NitaWe consider a U(1)(X) (R) Z(2) (R) Z(2)' extension of the Standard Model (SM), where the U(1)(X) charge of an SM field is given by a linear combination of its hypercharge and B-L number. Apart from the SM particle content, the model contains three right-handed neutrinos (RHNs) N-R(i) and two scalars Phi, chi, all singlets under the SM gauge group but charged under U(1)(X) gauge group. Two of these additional fields, fermion N-R(3) is odd under Z(2) and scalar chi is odd under Z(2)' symmetry. Thus both chi and N-R(3) contribute to the observed dark matter relic density, leading to two-component dark matter candidates. We study in detail its dark matter properties such as relic density and direct detection taking into account the constraints coming from collider studies. We find that in our model, there can be possible annihilation of one Dark Matter (DM) into the other, which may potentially alter the relic density in a significant way. (C) 2022 The Author(s). Published by Elsevier B.V.Heavy Majorana neutrino pair production from Z' at hadron and lepton colliders
http://hdl.handle.net/2115/86483
Title: Heavy Majorana neutrino pair production from Z' at hadron and lepton colliders
Authors: Das, Arindam; Mandal, Sanjoy; Nomura, Takaaki; Shil, Sujay
Abstract: A gauged U(1) extension of the Standard Model (SM) is a simple and anomaly-free framework where three generations of Majorana type right-handed neutrinos (RHNs) are introduced to generate light neutrino mass and flavor mixings through the seesaw mechanism. We investigate such models at different hadron and lepton colliders via Z' induced Majorana type RHNs pair production. We derive bounds on U(1) gauge coupling (g') comparing the model cross sections with experimentally observed data for different Z' mass (MZ') and RHNs mass (MN). Using these limits we estimate the allowed RHN pair production cross section which can be manifested by lepton number violating signatures in association with fat-jets at the hadron colliders depending on the mass of the RHNs. Hence we study dilepton and trilepton modes with fat-jet/s of the signal for different benchmark values of MZ' and MN. Using fat-jet signatures and studying the signal and corresponding SM backgrounds, we estimate bounds on MN-MZ' plane at different center of mass energies which could be probed at different hadron colliders. In the context of the lepton colliders we consider electron positron initial states where Majorana type RHNs can be produced from Z' manifesting same sign dilepton plus jets signature and trilepton plus jets in association with missing energy. Studying the signal and corresponding SM backgrounds we estimate the bounds on the MN-MZ' plane for different center of mass energies. In the context of the U(1) extension of the SM there is a SM singlet BSM scalar which couples with the RHNs. We can probe the Majorana nature of RHNs via this BSM scalar production at electron positron colliders.2022-05-22T15:00:00ZDas, ArindamMandal, SanjoyNomura, TakaakiShil, SujayA gauged U(1) extension of the Standard Model (SM) is a simple and anomaly-free framework where three generations of Majorana type right-handed neutrinos (RHNs) are introduced to generate light neutrino mass and flavor mixings through the seesaw mechanism. We investigate such models at different hadron and lepton colliders via Z' induced Majorana type RHNs pair production. We derive bounds on U(1) gauge coupling (g') comparing the model cross sections with experimentally observed data for different Z' mass (MZ') and RHNs mass (MN). Using these limits we estimate the allowed RHN pair production cross section which can be manifested by lepton number violating signatures in association with fat-jets at the hadron colliders depending on the mass of the RHNs. Hence we study dilepton and trilepton modes with fat-jet/s of the signal for different benchmark values of MZ' and MN. Using fat-jet signatures and studying the signal and corresponding SM backgrounds, we estimate bounds on MN-MZ' plane at different center of mass energies which could be probed at different hadron colliders. In the context of the lepton colliders we consider electron positron initial states where Majorana type RHNs can be produced from Z' manifesting same sign dilepton plus jets signature and trilepton plus jets in association with missing energy. Studying the signal and corresponding SM backgrounds we estimate the bounds on the MN-MZ' plane for different center of mass energies. In the context of the U(1) extension of the SM there is a SM singlet BSM scalar which couples with the RHNs. We can probe the Majorana nature of RHNs via this BSM scalar production at electron positron colliders.企業側からの視点によるインターンシップ研究の発展可能性に関する一考察
http://hdl.handle.net/2115/85100
Title: 企業側からの視点によるインターンシップ研究の発展可能性に関する一考察
Authors: 亀野, 淳
Abstract: 本稿では、これまでの大学生のインターンシップ研究においては受入れ側である企業側の視点によるものが少ないことを明らかにし、今後の研究発展の可能性について考察を行った。具体的には、企業側からみたインターンシップの意義・メリットについて整理を行った上で、企業側の視点でインターンシップの効果を、①新卒採用効果、②離職抑制・定着効果、③従業員の育成効果の3つに分類し、それぞれの先行研究を整理した。また、この3つの効果について、情報の非対称性、Realistic Job Preview(RJP)、採用ブランド力、リアリティショック、経験学習など人的資源管理論等の理論を援用しながら研究の到達点と発展可能性を考察した。さらに、インターンシップの周辺領域にある取組みとしてアルバイトや産学連携教育について取り上げ、これらの先行研究を整理するとともに、その位置づけや国際比較のあり方など研究発展性についても言及した。; This paper makes clear the fact that internship research for university students is insufficient in terms of research from the perspective of employers and considers the possibilities for future development of research. Specifically, after first reviewing the meaning and benefits of internships from the employer’s point of view, the effects of internships from the perspective of employers were grouped into the three categories of (i) effects on hiring of new graduates, (ii) effects on employee retention, and (iii) employee training effects, and previous studies on each of these effects were reviewed. In addition, for these three effects the end points and development possibilities of internship research were considered employing theories from fields such as human resources management, including those of information asymmetry, realistic job preview (RJP), employment brand power, reality shock, and experiential learning. Furthermore, activities such as part-time employment and education through industry-academy partnership were considered as initiatives in fields peripherally related to internships, reviewing previous studies on these and discussing the potential for future research on matters such as their positioning and international comparison.2021-04-13T15:00:00Z亀野, 淳本稿では、これまでの大学生のインターンシップ研究においては受入れ側である企業側の視点によるものが少ないことを明らかにし、今後の研究発展の可能性について考察を行った。具体的には、企業側からみたインターンシップの意義・メリットについて整理を行った上で、企業側の視点でインターンシップの効果を、①新卒採用効果、②離職抑制・定着効果、③従業員の育成効果の3つに分類し、それぞれの先行研究を整理した。また、この3つの効果について、情報の非対称性、Realistic Job Preview(RJP)、採用ブランド力、リアリティショック、経験学習など人的資源管理論等の理論を援用しながら研究の到達点と発展可能性を考察した。さらに、インターンシップの周辺領域にある取組みとしてアルバイトや産学連携教育について取り上げ、これらの先行研究を整理するとともに、その位置づけや国際比較のあり方など研究発展性についても言及した。
This paper makes clear the fact that internship research for university students is insufficient in terms of research from the perspective of employers and considers the possibilities for future development of research. Specifically, after first reviewing the meaning and benefits of internships from the employer’s point of view, the effects of internships from the perspective of employers were grouped into the three categories of (i) effects on hiring of new graduates, (ii) effects on employee retention, and (iii) employee training effects, and previous studies on each of these effects were reviewed. In addition, for these three effects the end points and development possibilities of internship research were considered employing theories from fields such as human resources management, including those of information asymmetry, realistic job preview (RJP), employment brand power, reality shock, and experiential learning. Furthermore, activities such as part-time employment and education through industry-academy partnership were considered as initiatives in fields peripherally related to internships, reviewing previous studies on these and discussing the potential for future research on matters such as their positioning and international comparison.脱炭素化技術のELSIとその評価枠組 : TAレポート
http://hdl.handle.net/2115/84398
Title: 脱炭素化技術のELSIとその評価枠組 : TAレポート
Authors: 脱炭素化技術ELSI プロジェクト
Description: JST-RISTEX RInCA プログラム「脱炭素化技術の日本での開発/普及推進戦略におけるELSI の確立」研究開発プロジェクト2022-03-24T15:00:00Z脱炭素化技術ELSI プロジェクトSterile neutrino dark matter with dipole interaction
http://hdl.handle.net/2115/84368
Title: Sterile neutrino dark matter with dipole interaction
Authors: Cho, Wonsub; Choi, Ki-Young; Seto, Osamu
Abstract: We consider the possibility of the lightest sterile neutrino dark matter which has dipole interaction with heavier sterile neutrinos. The lifetime can be long enough to be a dark matter candidate without violating other constraints and the correct amount of relic abundance can be produced in the early Universe. We find that a sterile neutrino with the mass of around MeV and the dimension-five nonrenormalizable dipole interaction suppressed by ?5 greater than or similar to 1015 GeV can be a good candidate of dark matter, while heavier sterile neutrinos with masses of the order of GeV can explain the active neutrino oscillations.2022-01-12T15:00:00ZCho, WonsubChoi, Ki-YoungSeto, OsamuWe consider the possibility of the lightest sterile neutrino dark matter which has dipole interaction with heavier sterile neutrinos. The lifetime can be long enough to be a dark matter candidate without violating other constraints and the correct amount of relic abundance can be produced in the early Universe. We find that a sterile neutrino with the mass of around MeV and the dimension-five nonrenormalizable dipole interaction suppressed by ?5 greater than or similar to 1015 GeV can be a good candidate of dark matter, while heavier sterile neutrinos with masses of the order of GeV can explain the active neutrino oscillations.Superheavy WIMP dark matter from incomplete thermalization
http://hdl.handle.net/2115/83619
Title: Superheavy WIMP dark matter from incomplete thermalization
Authors: Okada, Nobuchika; Seto, Osamu
Abstract: Although it is usually thought that a class of weakly interacting massive particle (WIMP) dark matters (DMs), which have the vector coupling with the Z boson, is denied by null results of the direct DM searches, such WIMP DMs are still viable if they are superheavy with the mass of m(DM) greater than or similar to 10(9) GeV. In the future, the superheavy WIMP DMs can be searched up to m(DM) similar or equal to 10(12) GeV, which corresponds to the so-called neutrino floor limit. We show that the observed abundance of Omega(DM)h(2) similar or equal to 0.1 for a superheavy WIMP DM can be reproduced by a suitable reheating temperature of T-R similar or equal to m(DM)/29 after inflation, if the direct inflaton decay into DM is negligible or kinematically forbidden. (C) 2021 The Author(s). Published by Elsevier B.V.2021-09-09T15:00:00ZOkada, NobuchikaSeto, OsamuAlthough it is usually thought that a class of weakly interacting massive particle (WIMP) dark matters (DMs), which have the vector coupling with the Z boson, is denied by null results of the direct DM searches, such WIMP DMs are still viable if they are superheavy with the mass of m(DM) greater than or similar to 10(9) GeV. In the future, the superheavy WIMP DMs can be searched up to m(DM) similar or equal to 10(12) GeV, which corresponds to the so-called neutrino floor limit. We show that the observed abundance of Omega(DM)h(2) similar or equal to 0.1 for a superheavy WIMP DM can be reproduced by a suitable reheating temperature of T-R similar or equal to m(DM)/29 after inflation, if the direct inflaton decay into DM is negligible or kinematically forbidden. (C) 2021 The Author(s). Published by Elsevier B.V.高齢化の進展等に伴う企業内賃金格差についての実証分析
http://hdl.handle.net/2115/83232
Title: 高齢化の進展等に伴う企業内賃金格差についての実証分析
Authors: 亀野, 淳2001-08-31T15:00:00Z亀野, 淳日本的雇用システムの変化と若年者の雇用・人材育成
http://hdl.handle.net/2115/83231
Title: 日本的雇用システムの変化と若年者の雇用・人材育成
Authors: 亀野, 淳
Abstract: 本稿は日本的雇用システムの変化が若年雇用や学歴・学校歴に及ぼす影響について考察したものである。
日本的雇用システムの変化は,そのメリットを否定したわけではなく,むしろメリットを維持するための修正とみるべきである。変化の方向性としては,新規学卒者の採用人数の絞込み,遅い選抜方法の見直し,人材育成における対象者の絞込みや自己啓発への期待などがあげられる。新規学卒者の採用人数の絞込みは,単純に若年者の雇用環境の悪化だけではなく学歴や学校歴による格差が大きくなると見込まれる。また遅い選抜方法の見直しは,選考基準として学校歴がより重視される傾向になると見込まれる。さらに人材育成における対象者の絞込みや自己啓発への期待は,ビジネススクールなどの専門職大学院の対する社会的ニーズは高まると予想されるが,大卒者の相対的地位の低下を招き新たな若年者の雇用問題を発生させるおそれもある。
このように日本的雇用システムの変化は,若年者の雇用環境の悪化や学歴・学校歴による格差を拡大させるおそれがある。したがって今後は正規社員と非正規社員の処遇格差の是正や非正規社員に対する人材育成やマネジメントの必要性が高まる。; This paper discusses the impact of changes to Japanese employment system on the employment of the younger generation, on academic background, and attended schools.Changes to the Japanese employment system do not serve to undermine its merits, but instead should be viewed as a correction to continue those merits. Potential directions for change include reducing the numbers of new graduates hired, re-evaluating selection methods for late applicants, decreasing the number of candidates that enter into human resources training, and increasing expectations for self-development. Reducing the numbers of new graduates hired not only simply worsens the employment outlook for young people, but also could result in greater hiring disparity for differences in academic background or attended schools. A re-evaluation of the selection method for late applicants could have result in a greater tendency to place emphasis on the candidate's attended school as a selection criterion. Further-more, decreasing the number of candidates who enter into human resources training, and increasing expectations for self-development could raise the social requirements for specialized degree programs such as business schools, but this leads to a reduction in the relative worth of university graduates, and runs the risk of causing new employment problems for younger people.These kinds of changes to the Japanese employment system run the risk of worsening the employment outlook for young people and widening the disparities of academic background or attended school. Therefore, in the future, there is an in-creased requirement for corrective actions to reduce disparity between permanent employees and non-permanent employees, and the establishment of programs for personal development and management of non-permanent employees.2005-06-09T15:00:00Z亀野, 淳本稿は日本的雇用システムの変化が若年雇用や学歴・学校歴に及ぼす影響について考察したものである。
日本的雇用システムの変化は,そのメリットを否定したわけではなく,むしろメリットを維持するための修正とみるべきである。変化の方向性としては,新規学卒者の採用人数の絞込み,遅い選抜方法の見直し,人材育成における対象者の絞込みや自己啓発への期待などがあげられる。新規学卒者の採用人数の絞込みは,単純に若年者の雇用環境の悪化だけではなく学歴や学校歴による格差が大きくなると見込まれる。また遅い選抜方法の見直しは,選考基準として学校歴がより重視される傾向になると見込まれる。さらに人材育成における対象者の絞込みや自己啓発への期待は,ビジネススクールなどの専門職大学院の対する社会的ニーズは高まると予想されるが,大卒者の相対的地位の低下を招き新たな若年者の雇用問題を発生させるおそれもある。
このように日本的雇用システムの変化は,若年者の雇用環境の悪化や学歴・学校歴による格差を拡大させるおそれがある。したがって今後は正規社員と非正規社員の処遇格差の是正や非正規社員に対する人材育成やマネジメントの必要性が高まる。
This paper discusses the impact of changes to Japanese employment system on the employment of the younger generation, on academic background, and attended schools.Changes to the Japanese employment system do not serve to undermine its merits, but instead should be viewed as a correction to continue those merits. Potential directions for change include reducing the numbers of new graduates hired, re-evaluating selection methods for late applicants, decreasing the number of candidates that enter into human resources training, and increasing expectations for self-development. Reducing the numbers of new graduates hired not only simply worsens the employment outlook for young people, but also could result in greater hiring disparity for differences in academic background or attended schools. A re-evaluation of the selection method for late applicants could have result in a greater tendency to place emphasis on the candidate's attended school as a selection criterion. Further-more, decreasing the number of candidates who enter into human resources training, and increasing expectations for self-development could raise the social requirements for specialized degree programs such as business schools, but this leads to a reduction in the relative worth of university graduates, and runs the risk of causing new employment problems for younger people.These kinds of changes to the Japanese employment system run the risk of worsening the employment outlook for young people and widening the disparities of academic background or attended school. Therefore, in the future, there is an in-creased requirement for corrective actions to reduce disparity between permanent employees and non-permanent employees, and the establishment of programs for personal development and management of non-permanent employees.