Analyzing neuroimaging data with subclasses: A shrinkage approach

Hohne, J.,Bartz, D.,Hebart, M.N.,Muller, K.R.,Blankertz, B. ACADEMIC PRESS 2016 NEUROIMAGE Vol.124 No.1

Among the numerous methods used to analyze neuroimaging data, Linear Discriminant Analysis (LDA) is commonly applied for binary classification problems. LDAs popularity derives from its simplicity and its competitive classification performance, which has been reported for various types of neuroimaging data. Yet the standard LDA approach proves less than optimal for binary classification problems when additional label information (i.e. subclass labels) is present. Subclass labels allow to model structure in the data, which can be used to facilitate the classification task. In this paper, we illustrate how neuroimaging data exhibit subclass labels that may contain valuable information. We also show that the standard LDA classifier is unable to exploit subclass labels. We introduce a novel method that allows subclass labels to be incorporated efficiently into the classifier. The novel method, which we call Relevance Subclass LDA (RSLDA), computes an individual classification hyperplane for each subclass. It is based on regularized estimators of the subclass mean and uses other subclasses as regularization targets. We demonstrate the applicability and performance of our method on data drawn from two different neuroimaging modalities: (I) EEG data from brain-computer interfacing with event-related potentials, and (II) fMRI data in response to different levels of visual motion. We show that RSLDA outperforms the standard LDA approach for both types of datasets. These findings illustrate the benefits of exploiting subclass structure in neuroimaging data. Finally, we show that our classifier also outputs regularization profiles, enabling researchers to interpret the subclass structure in a meaningful way. RSLDA therefore yields increased classification accuracy as well as a better interpretation of neuroimaging data. Since both results are highly favorable, we suggest to apply RSLDA for various classification problems within neuroimaging and beyond.

MODELING OF A BUOYANCY-DRIVEN FLOW EXPERIMENT IN PRESSURIZED WATER REACTORS USING CFD-METHODS

Hohne, Thomas,Kliem, Soren Korean Nuclear Society 2007 Nuclear Engineering and Technology Vol.39 No.4

The influence of density differences on the mixing of the primary loop inventory and the Emergency Core Cooling (ECC) water in the downcomer of a Pressurised Water Reactor (PWR) was analyzed at the ROssendorf COolant Mixing (ROCOM) test facility. ROCOM is a 1:5 scaled model of a German PWR, and has been designed for coolant mixing studies. It is equipped with advanced instrumentation, which delivers high-resolution information for temperature or boron concentration fields. This paper presents a ROCOM experiment in which water with higher density was injected into a cold leg of the reactor model. Wire-mesh sensors measuring the tracer concentration were installed in the cold leg and upper and lower part of the downcomer. The experiment was run with 5% of the design flow rate in one loop and 10% density difference between the ECC and loop water especially for the validation of the Computational Fluid Dynamics (CFD) software ANSYS CFX. A mesh with two million control volumes was used for the calculations. The effects of turbulence on the mean flow were modelled with a Reynolds stress turbulence model. The results of the experiment and of the numerical calculations show that mixing is dominated by buoyancy effects: At higher mass flow rates (close to nominal conditions) the injected slug propagates in the circumferential direction around the core barrel. Buoyancy effects reduce this circumferential propagation. Therefore, density effects play an important role during natural convection with ECC injection in PWRs. ANSYS CFX was able to predict the observed flow patterns and mixing phenomena quite well.

우상엽 흡입성 폐렴과 이차성 부신기능부전증을 동반한 75세 남자환자

徐柄權,인요한,吳重山 대한의사협회 1999 대한의사협회지 Vol.42 No.10

Expanding the Genetic Code of Escherichia coli with Phosphoserine

Park, H.-S.,Hohn, M. J.,Umehara, T.,Guo, L.-T.,Osborne, E. M.,Benner, J.,Noren, C. J.,Rinehart, J.,Soll, D. American Association for the Advancement of Scienc 2011 Science Vol.333 No.6046

A Study on Improving HCI User Experience in The Maritime Business - Fleet Maintenance System Based on HCD Principles

Chengsi Li,Falk Hohn,Younghwan Pan 한국HCI학회 2023 한국HCI학회 학술대회 Vol.2023 No.2

The international shipping industry is responsible for transporting approximately 90% of world trade, making ship safety one of the most important aspects of transportation. Installing predictive maintenance systems on ships is a technology that is not yet widespread, and its high price tag makes it unaffordable for many small and medium-sized enterprises(SMEs). As a result, many shipping companies are busy repairing ship defects that are discovered too late and are always at risk of falling into extreme additional costs. My practice partner developed a corresponding web application for this purpose, and although no technical problems were found during the more than one-year testing phase, the fact that the program was developed without the involvement of a user experience(UX) designer led to criticism from users about the cluttered information categorization and the unfriendly logic of the systems operation. Therefore, in this study, I addressed this issue by experimenting with user behavior based on the principles of human-centered design (HCD) and user habits. It also shows that UX designers need to have the ability to collaborate on interdisciplinary projects alone.

Towards Noninvasive Hybrid Brain–Computer Interfaces: Framework, Practice, Clinical Application, and Beyond

Muller-Putz, Gernot,Leeb, Robert,Tangermann, Michael,Hohne, Johannes,Kubler, Andrea,Cincotti, Febo,Mattia, Donatella,Rupp, Rudiger,Muller, Klaus-Robert,Del R Millan, Jose IEEE 2015 Proceedings of the Institute of Electrical and Ele Vol.103 No.6

<P>In their early days, brain-computer interfaces (BCIs) were only considered as control channel for end users with severe motor impairments such as people in the locked-in state. But, thanks to the multidisciplinary progress achieved over the last decade, the range of BCI applications has been substantially enlarged. Indeed, today BCI technology cannot only translate brain signals directly into control signals, but also can combine such kind of artificial output with a natural muscle-based output. Thus, the integration of multiple biological signals for real-time interaction holds the promise to enhance a much larger population than originally thought end users with preserved residual functions who could benefit from new generations of assistive technologies. A BCI system that combines a BCI with other physiological or technical signals is known as hybrid BCI (hBCI). In this work, we review the work of a large scale integrated project funded by the European commission which was dedicated to develop practical hybrid BCIs and introduce them in various fields of applications. This article presents an hBCI framework, which was used in studies with nonimpaired as well as end users with motor impairments.</P>

Colon Capsule Endoscopy: Indications, Findings, and Complications – Data from a Prospective German Colon Capsule Registry Trial (DEKOR)

Johannes Hausmann,Andrea Tal,Artur Gomer,Michael Philipper,Gero Moog,Horst Hohn,Norbert Hesselbarth,Harald Plass,Jörg Albert,Fabian Finkelmeier 대한소화기내시경학회 2021 Clinical Endoscopy Vol.54 No.1

Background/Aims: Reliable and especially widely accepted preventive measures are crucial to further reduce the incidenceof colorectal cancer (CRC). Colon capsule endoscopy (CCE) might increase the screening numbers among patients unable orunwilling to undergo conventional colonoscopy. This registry trial aimed to document and determine the CCE indications, findings,complications, and adverse events in outpatient practices and clinics throughout Germany. Methods: Patients undergoing CCE between 2010 and 2015 were enrolled in this prospective multicenter registry trial at six Germancenters. Patient demographics, outcomes, and complications were evaluated. Results: A total of 161 patients were included. Of the CCE evaluations, 111 (68.9%) were considered successful. Pathological findingsin the colon (n=92, 60.1%) and in the remaining gastrointestinal tract (n=38, 24.8%) were recorded. The main finding was thepresence of polyps (n=52, 32.3%). Furthermore, five carcinomas (3.1%) were detected and histologically confirmed later. Adequatebowel cleanliness was more likely to be achieved in the outpatient setting (p<0.0001). Interestingly, 85 patients (55.6%) chose toundergo CCE based on personal motivation. Conclusions: CCE seems to be a reliable and safe endoscopic tool for screening for CRC and detecting other diseases. Its patientacceptance and feasibility seems to be high, especially in the outpatient setting.

Trivalent M-related protein as a component of next generation group A streptococcal vaccines

Harry S. Courtney,Shannon E. Niedermeyer,Thomas A. Penfound,Claudia M. Hohn,Adam Greeley,James B. Dale 대한백신학회 2017 Clinical and Experimental Vaccine Research Vol.6 No.1

Purpose: There is a need to broaden protective coverage of M protein–based vaccines against group A streptococci (GAS) because coverage of the current 30-valent M protein vaccine does not extend to all emm types. An additional GAS antigen and virulence factor that could potentially extend vaccine coverage is M-related protein (Mrp). Previous work indicated that there are three structurally related families of Mrp (MrpI, MrpII, and MrpIII) and peptides of all three elicited bactericidal antibodies against multiple emm types. The purpose of this study was to determine if a recombinant form containing Mrp from the three families would evoke bactericidal antiserum and to determine if this antiserum could enhance the effectiveness of antisera to the 30-valent M protein vaccine. Materials and Methods: A trivalent recombinant Mrp (trMrp) protein containing N-terminal fragments from the three families (trMrp) was constructed, purified and used to immunize rabbits. Anti-trMrp sera contained high titers of antibodies against the trMrp immunogen and recombinant forms representing MrpI, MrpII, and MrpIII. Results: The antisera opsonized emm types of GAS representing each Mrp family and also opsonized emm types not covered by the 30-valent M protein–based vaccine. Importantly, a combination of trMrp and 30-valent M protein antiserum resulted in higher levels of opsonization of GAS than either antiserum alone. Conclusion: These findings suggest that trMrp may be an effective addition to future constructs of GAS vaccines.

Cellobiose Hydrolysis Using Acid-functionalized Nanoparticles

L. Peña,M. Ikenberry,B. Ware,K. L. Hohn,D. Boyle,X. S. Sun,D. Wang 한국생물공학회 2011 Biotechnology and Bioprocess Engineering Vol.16 No.6

Mineral acids have been used effectively for the pretreatment of cellulosic biomass to improve sugar recovery and promote its conversion to ethanol; however,substantial capital investment is required to enable separation of the acid, and corrosion-resistant materials are necessary. Disposal and neutralization costs are also concerns because they can decrease the economic feasibility of the process. In this work, three acid-functionalized nanoparticles were synthesized for pretreatment and hydrolysis of lignocellulosic biomass. Silica-protected cobalt spinel ferrite nanoparticles were functionalized with perfluoroalkylsulfonic acid (PFS), alkylsulfonic acid (AS), and butylcarboxylic acid (BCOOH) groups. These nanoparticles were magnetically separated from the reaction media and reused. TEM images showed that the average diameter was 2 nm for both PFS and BCOOH nanoparticles and 7 nm for AS nanoparticles. FTIR confirmed the presence of sulfonic and carboxylic acid functional groups. Ion exchange titration measurements yielded 0.9, 1.7, and 0.2mmol H+/g of catalyst for PFS, AS, and BCOOH nanoparticles,respectively. Elemental analysis results indicated that PFS and AS nanoparticles had 3.1 and 4.9% sulfur,respectively. Cellobiose hydrolysis was used as a model reaction to evaluate the performance of acid-functionalized magnetic nanoparticles for breaking β-(1→4) glycosidic bonds. Cellobiose conversion of 78% was achieved when using AS nanoparticles as the catalyst at 175°C for 1 h,which was significantly higher than the conversion for the control experiment (52%). AS nanoparticles retained more than 60% of their sulfonic acids groups after the first run,and 65 and 60% conversions were obtained for the second and third runs, respectively.

여행업 창업의지의 영향요인에 관한 연구 -내부환경요인과 직업가치, 직무만족 요인을 중심으로-

이완기(Lee WonKi),이소윤(Lee Soyun),한상진(Han Sangjin),정환(Jeong Hohn) 한국창업학회 2013 한국창업학회지 Vol.8 No.3

This study examined the effects of internal, work value and Job satisfaction factors, as the ones influencing entrepreneurial intention for travel agency. Through factor analysis, job attachment, incentive compensation, and human relations have been examined as internal factors; ability appreciation, comparative advantage, and social recognition, as work value factors; treated conditions, working conditions, company s reputation, etc, as job satisfaction factors. After Focus Group Interview Survey being conducted, targeting travel professionals with more than 10 years experience working in travel agency, the data from a total of 60 responses was used in the final analysis. Stepwise regression analysis was carried, which included variables in the regression equation in the order of the ones with the highest influence and explanatory power, among possible variables affecting entrepreneurial intention. The results were as follows: First, it showed that among the internal factors, incentive compensation factor has the greatest impact on the entrepreneurial intention; second, among the job satisfaction, treated conditions factor has an impact on it; third, among work value, social recognition factor has an impact on it. These findings are expected to provide a new direction for new business-related empirical studies for related industries in the future.