Impact of Internal Design on the Efficiency of IT Equipment in a Hot Aisle Containment System: An Experimental Study

2018 ◽  
Author(s):  
Sadegh Khalili ◽  
Husam Alissa ◽  
Kourosh Nemati ◽  
Mark Seymour ◽  
Robert Curtis ◽  
...  
Keyword(s):  
Airflow Rate ◽  
Hot Air ◽  
Flow Through ◽  
Overall Performance ◽  
Fan Speed ◽  
And Performance ◽  
Cold Aisle Containment ◽  
Different Characteristics ◽  
Network Switches ◽  
The Impact

There are various designs for segregating hot and cold air in data centers such as cold aisle containment (CAC), hot aisle containment (HAC), and chimney exhaust rack. These containment systems have different characteristics and impose various conditions on the information technology equipment (ITE). One common issue in HAC systems is the pressure buildup inside the HAC (known as backpressure). Backpressure also can be present in CAC systems in case of airflow imbalances. Hot air recirculation, limited cooling airflow rate in servers, and reversed flow through ITE with weaker fan systems (e.g. network switches) are some known consequences of backpressure. Currently there is a lack of experimental data on the interdependency between overall performance of ITE and its internal design when a backpressure is imposed on ITE. In this paper, three commercial 2-rack unit (RU) servers with different internal designs from various generations and performance levels are tested and analyzed under various environmental conditions. Smoke tests and thermal imaging are implemented to study the airflow patterns inside the tested equipment. In addition, the impact leak of hot air into ITE on the fan speed and the power consumption of ITE is studied. Furthermore, the cause of the discrepancy between measured inlet temperatures by internal intelligent platform management interface (IPMI) and external sensors is investigated. It is found that arrangement of fans, segregation of space upstream and downstream of fans, leakage paths, location of sensors of baseboard management controller (BMC) and presence of backpressure can have a significant impact on ITE power and cooling efficiency.

Impact of Server Thermal Design on the Cooling Efficiency: Chassis Design

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Sadegh Khalili ◽  
Husam Alissa ◽  
Kourosh Nemati ◽  
Mark Seymour ◽  
Robert Curtis ◽  
...  
Keyword(s):  
Thermal Design ◽  
Airflow Rate ◽  
Cooling Efficiency ◽  
Hot Air ◽  
Flow Through ◽  
Fan Speed ◽  
And Performance ◽  
Cold Aisle Containment ◽  
Different Characteristics ◽  
The Impact

There are various designs for segregating hot and cold air in data centers such as cold aisle containment (CAC), hot aisle containment (HAC), and chimney exhaust rack. These containment systems have different characteristics and impose various conditions on the information technology equipment (ITE). One common issue in HAC systems is a pressure build-up inside the HAC (known as backpressure). Backpressure also can be present in CAC systems in case of airflow imbalances. Hot air recirculation, limited cooling airflow rate in servers, and reversed flow through ITE with weaker fan systems (e.g., network switches) are some known consequences of backpressure. Currently, there is a lack of experimental data on the interdependency between overall performance of ITE and its internal design when backpressure is imposed on ITE. In this paper, three commercial 2-rack unit (RU) servers with different internal designs from various generations and performance levels are tested and analyzed under various environmental conditions. Smoke tests and thermal imaging are implemented to study the airflow patterns inside the tested equipment. In addition, the impact of hot air leakage into the servers through chassis perforations on the fan speed and the power consumption of the servers are studied. Furthermore, the cause of the discrepancy between measured inlet temperatures by the intelligent platform management interface (IPMI) and external sensors is investigated. It is found that arrangement of fans, segregation of space upstream and downstream of fans, leakage paths, the location of baseboard management controller (BMC) sensors, and the presence of backpressure can have a significant impact on ITE power and cooling efficiency.

COMPARATIVE META-ANALYTIC EVALUATION OF THE IMPACT OF SUPPLY CHAIN INTEGRATION ON PERFORMANCE: A DETAILED PERSPECTIVE OF MODERATOR AND MEDIATOR ANALYSIS

2021 ◽  
Vol 1 (1) ◽  
pp. 43-69
Author(s):  
Augustine Castro Singine ◽  
Mustafa Cahid Ungan
Keyword(s):  
Supply Chain ◽  
Business Performance ◽  
Meta Analysis ◽  
Mediation Effect ◽  
Customer Integration ◽  
Relational Integration ◽  
Mediator Analysis ◽  
Overall Performance ◽  
And Performance ◽  
The Impact

In an environment with ever changing customers’ needs and intensifying global competition, quality processes and supply chain (SC) are critical for organisational success. To satisfy customers, outsmart competition and improve performance, contemporary organisations are trying to improve on their processes through integrated supply chains. In an attempt to address this question and effectively contribute to this topic, a comparative meta- analytical evaluation along with key moderator and mediator analysis was conducted. In the lens of many theories, SCI from two perspectives; SCID (internal, suppliers, customer integration) with 67 studies and SCIF (information, operational, relational integration) with 25 studies was assessed on overall performance as well as on both operational and business performance. A quantitative meta-analysis based on Hunter and Schmidt (2004) which was performed through Jamovi, revealed the following: The meta-analysis results which were obtained through Jamovi provided significant correlation coefficients for SCID and SCIF respectively (ř = .476, p <.002) and (ř =.508, p <.001). Therefore, indicating that the association between SCID and performance is medium and positive, while that of SCIF and performance is positive and large. This is a clear indication that SCI from the perspective of SCID and SCIF yields different results, with SCIF having a relatively large effect. Moreover, on average SCIF both at aggregate and individual level has a slightly large effect on performance than SCID. Operational performance was the most influenced by SCID and SCIF, although operational and relational integration indicated a significant larger effect on business performance. Thus, individual SCID and SCIF constructs have different effects on business and operational as overall performance. All moderators though with different levels of interactions indicated a significant effect on both SCID and SCIF. Of the three mediators tested, customer integration had a 32% negative effect, SC agility showed an 89.1% full mediation effect with flexibility indicating a 53% significant effect.

scholarly journals Specialization and Performance: Evidence from NCAA 4 × 400 m Relay Times

Economies ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 96
Author(s):  
Candon Johnson ◽  
Robert Schultz ◽  
Joshua C. Hall
Keyword(s):  
Performance Measure ◽  
Division I ◽  
Division Iii ◽  
Overall Performance ◽  
The Difference ◽  
And Performance ◽  
Using Data ◽  
The Impact ◽  
Better Than

This paper investigates the impact of having open 400 meter (400 m) runners on NCAA relay teams. Using data from 2012–2016 containing the top 100 4 × 400 m in each NCAA Division relay times for each year, it is found that more 400 m specialists lead to an increase in the overall performance of the team, measured by a decrease in relay times. The effect is examined across Division I–III NCAA track teams. The results are consistent across each division. We view this as a test of the role of specialization on performance. Using runners who specialize in 400 m races should increase overall team performance as long as specialization does not lead to an inefficient allocation of team human capital. An additional performance measure is used examining the difference between projected and actual relay times. Divisions I and II are found to perform better than projected with an increase in 400 m runners, but there is no effect found in Division III.

scholarly journals The Impact of Training and Motivation on Employee Performance in the Banking Sector

2021 ◽  
Vol 11 (4) ◽  
pp. 5501-5519
Author(s):  
D. Subha ◽  
Sonali Bhattacharya
Keyword(s):  
Banking Sector ◽  
Employee Performance ◽  
Training And Development ◽  
Training Motivation ◽  
Overall Performance ◽  
Effectiveness And Efficiency ◽  
Level Of Training ◽  
And Performance ◽  
Strongly Agree ◽  
The Impact

The concept of Training, Motivation, and Performance are the variables examined under the study to evaluate their effect in the Banking Sector. Productivity is one of the most significant elements that influence the organization's general performance, which compromises with different elements like training, attitude, motivation, and work environment for creativity contribute to the overall success of the employees. The current examination explores the impact of worker proficiency and efficiency of training and motivation. A questionnaire was administered to employees of the banking sector to identify the perceived level of training and motivation that emphasizes the overall performance. The three variables were estimated on a five-point Likert scale choice. Five were the most important (strongly agree), and one being the least important (strongly disagree). The sample of the questionnaire schedule was self-prepared. The study result shows that training and motivation positively impact the effectiveness and efficiency of the employees. Also, the study features the training and development procedure of the financial area that should utilize to proper workers and increment their performance and analyzes the needs of training and motivation in the workplace.

Ranking and Optimization of CAC and HAC Leakage Using Pressure Controlled Models

2015 ◽  
Author(s):  
Husam A. Alissa ◽  
Kourosh Nemati ◽  
Bahgat Sammakia ◽  
Kanad Ghose ◽  
Mark Seymour ◽  
...  
Keyword(s):  
Data Center ◽  
Management Practices ◽  
Real Life ◽  
Pressure Differential ◽  
Hot Air ◽  
Containment Model ◽  
Cooling Unit ◽  
Unit Model ◽  
Cold Aisle Containment ◽  
Different Characteristics

In cold aisle containment (CAC) the supply of cold air is separated within the contained volume. The hot air exhaust leaves the IT and increases the room’s temperature before returning to the cooling unit. On the other hand, hot aisle containment (HAC) generates a cooler environment in the data center room as a whole by segregating hot air within the containment. Hot air is routed back to the cooling unit return by a drop ceiling or a chimney. Each system has different characteristics and airflow paths. For instance, leakage introduces different effects for CACs and HACs since the hot and cold aisles are switched. This article utilizes data center measurements and containment characterization carried out circa April 2015 in the ES2 Data Center lab at Binghamton University. Details on the containment model include leakages at below racks, above racks, below CAC doors, between doors, and above doors. The model deploys the experimentally obtained flow curves approach for flow-pressure correlation. Data center operators rely on the pressure differential to measure how much the IT is provided. Hence, in this study the level of provisioning was expressed in terms of pressure differentials between the hot and cold aisles. In this manner the model reflected real-life DC thermal management practices. This was done by integrating a pressure differential based controller to the cooling unit model. Leakages in each system are quantified and ranked based on a proposed LIF (Leakage Impact Factor) metric. The LIF describes the transport contribution each leakage location has. This metric can be used by containment designers and data center operators to prioritize their sealing efforts or consider deploying the containment solution differently. Finally, a systematic approach is shown in which containment models can be used to optimize operations at the real-life site.

Manifest conflict, customer orientation and performance outcomes in international buyer-seller relationships

2017 ◽  
Vol 32 (8) ◽  
pp. 1062-1072 ◽  
Author(s):  
Civilai Leckie ◽  
Robert E. Widing ◽  
Gregory J. Whitwell
Keyword(s):  
Customer Orientation ◽  
Performance Outcomes ◽  
Best Interests ◽  
Content Type ◽  
Business Outcomes ◽  
Channel Relationships ◽  
Practical Standpoint ◽  
Overall Performance ◽  
And Performance ◽  
The Impact

Purpose The purpose of this paper is to test the impact of manifest conflict on performance outcomes. In particular, this paper aims to examine the moderating effect of the supplier’s customer orientation (CO) as perceived by the buyer on the conflict-performance outcomes relationships in international channel relationships. Design/methodology/approach A survey of 162 Australian importers was conducted to elucidate the associations among manifest conflict, CO and performance outcomes. Findings Manifest conflict was found to be negatively related to the importer’s evaluation of the exporter’s overall performance, which is consistent with previous work. However, CO was found to moderate the negative direct effect of manifest conflict on two outcome measures, “satisfaction with business outcomes” and the “evaluation of the exporter’s overall performance”. Moreover, it actually changed the effect from dysfunctional to functional for “evaluation of the exporter’s overall performance”. That is, CO changes the nature of the manifest conflict–outcome relationship by turning it from negative to positive. Research limitations/implications This research helps answer the appeal for research on the conditions in which conflict causes dysfunctional and functional outcomes. From a practical standpoint, providing the importer views the exporter as being customer-oriented, conflict should not be avoided if it stems from disagreements that arise due to the exporter acting in the best interests of the importer. The power of CO in affecting the functionality of outcomes resulting from conflict should be highlighted. Originality/value Conflict is a fact of life in channel relationships, but little is known about its functional and dysfunctional effects (Frazier, 1999; Skarmeas, 2006). The empirical evidence largely points to conflict being dysfunctional; however, research also indicates that context can play an important role in moderating the functionality of conflict. In this paper the authors ask: what role does CO play as a determinant of the functionality of manifest conflict in channel relationships? They argue that the exporter’s CO changes the context in which the importer and the exporter interact and, thereby, changes the way in which the importer interprets the supplier’s actions.

EFFECT OF PERFORMANCE APPRAISAL SYSTEM ON MOTIVATION AND PERFORMANCE OF ACADEMICS IN NIGERIAN PUBLIC UNIVERSITIES

2013 ◽  
Vol 03 (03) ◽  
pp. 20-28
Author(s):  
OJOKUKU R.M.
Keyword(s):  
Performance Appraisal ◽  
Public Universities ◽  
National Development ◽  
University Education ◽  
University Management ◽  
Appraisal System ◽  
Performance Appraisal System ◽  
Overall Performance ◽  
And Performance ◽  
The Impact

Nigerian universities are presently experiencing a number of challenges, primary among which is dearth of experienced academics, due to the mass exodus of lecturers to other countries in Africa and overseas, where the environment is more conducive to work and remuneration packages are more competitive. Series of research studies have established that a strong relationship exists between human resource (HR) practices and employee motivation and performance; however much still needs to be done in terms of investigating how it applies to academics in Nigerian universities. This study therefore set out to examine the impact of performance appraisal (PA), which is a key HR practice, on the motivation and performance of academics in Nigerian universities. The study sample was drawn from four (4) public universities in south western Nigeria. Data was sourced with the aid of a questionnaire, while percentage and multiple regression analysis were used for data analysis. Findings showed that the university academics see their performance appraisal system as not being accurate and fair enough because it does not capture adequately, all the job components that make up their performance during the review period. The performance appraisal system was also found to exert a strong influence on the academics’ motivation and overall performance. It was recommended that the PA system for academics should be reviewed by university management such that all the components of their job are captured, evaluated, and adequately rewarded. This is expected to impact positively on the motivation and overall performance of the academics, thereby working as a veritable tool for steering university education towards the right direction for national development.

The Impact of Area Contact Between Sensor Bulb and Evaporator Return Line in a Modular Refrigeration Unit: Part I — Computational Study

2003 ◽  
Author(s):  
Nikhil Lakhkar ◽  
Saket Karajgikar ◽  
Dereje Agonafer ◽  
Roger Schmidt
Keyword(s):  
Computational Study ◽  
Junction Temperature ◽  
Evaporator Temperature ◽  
Thermally Induced ◽  
Performance Improvements ◽  
Refrigeration Unit ◽  
Expansion Valve ◽  
Flow Through ◽  
And Performance ◽  
The Impact

The combination of increased power dissipation and increased packaging density has led to substantial increase in junction temperature, at both the chip and module level in computers and especially at the high-end. In the past, virtually all-commercial computers were designed to operate at temperatures above the ambient and were primarily air-cooled. However, researchers have always known the advantages of operating electronics at low temperatures. This facilitates faster switching time of semiconductor devices, increased circuit speeds due to lower electrical resistance of interconnecting materials and reduction in thermally induced failures of devices and components. Depending on the doping characteristics of the chip, performance improvement ranges from 1 to 3% for every 10°C lower transistor temperature can be realized. The paper addresses improving the cooling of IBM’s high-end server unit, which uses a conventional refrigeration system to maintain the chip temperatures below that of comparable air-cooled systems, but well above cryogenic temperature. The IBM S/390 high-end server system is the first IBM design that employed refrigeration cooling. Advantage of using refrigeration unit is improvement in reliability, and performance improvements related to the lower operating temperature. In previous work, the focus was to study the effect of variation of evaporator outlet superheat on the flow through the thermostatic expansion valve at varying evaporator temperature. Also the effect of change in bulb location and effect of bulb time constant on the hunting at the evaporator has been reported. Currently, the evaporator return line and the sensor bulb are simply attached with a clip, with no thermal consideration. In the present study, the performance that results from varying the area of contact between the evaporator return line and sensor bulb is discussed. Subsequently, the effect of various interface materials on the performance is examined.

scholarly journals Job Resourcefulness, Customer Orientation and Employees Outcomes: A Study of Hotel Employees in Pakistan

2018 ◽  
Vol 9 (6) ◽  
pp. 6-17
Author(s):  
Afsheen Fatima ◽  
Sarah Salah Uddin ◽  
Saba Mehmood ◽  
Ashfeen Bibi
Keyword(s):  
Career Satisfaction ◽  
Customer Orientation ◽  
Future Research ◽  
Twin Cities ◽  
Job Engagement ◽  
Employee Outcomes ◽  
Satisfaction Scale ◽  
Overall Performance ◽  
And Performance ◽  
The Impact

Increased competition and a rapidly changing environment present a huge challenge to organizations in implementing effective human capital and development strategies to boost their efficiency and overall performance. An organization’s human resource is definitively its most significant asset. The provisions of important job resources help workforce perform their job in an efficient way. These resources are very important for employee satisfaction and performance of the organization. This study was carried out to examine the impact of job resourcefulness (JR) on two employee outcomes i.e., job engagement and career satisfaction directly as well as indirectly through customer orientation. A convenient sample of 257 employees was taken from hospitality industry within twin cities of Pakistan (Rawalpindi and Islamabad). Questionnaires were used to collect data using a five-point Likert type scale. Job resourcefulness was operationalized using four items from Harris et al. (2006) whereas customer orientation was measured using four items from Licata et al. (2003). Five items were selected from career satisfaction scale developed by Greenhaus et al. (1990). Finally, nine items scale of job engagement developed by (Schaufeli, Bakker et al. 2006) was also used. The results exhibit that all the variables are positively and significantly related. Moreover, the findings are indicative of customer orientation’s role as a mediator between job resourcefulness and employee outcomes. Recommendations for future research and research implications are also discussed at the end of the paper. 

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