• 한국물환경학회지
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• 제20권3호
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• pp.206-214
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• 2004

Residual wall thicknesses, corrosion rates, and residual life of thirty four samples of cast iron pipes(CIPs) and ductile cast iron pipes(DCIPs) collected from water mains of B city were studied to estimate their remaining service life or optimum time of rehabilitation. The internal maximum corrosion depths of samples measured using a dial gauge after shot blasting were twice higher than the external in most cases. Therefore corrosion of water pipes was much more affected by internal water quality than soil. Residual wall thicknesses of DCIPs were higher than those of CIPs. That reason was thought to be that DCIPs have been protected from internal corrosion by lining cement mortar. Residual life calculated by maximum corrosion rate was ranged up to 44 years with 12.40 years average. Since most CIPs were much deteriorated, rehabilitation plan should be established soon in B city. Residual life of DCIP was 33.52 years average. When cement mortar lining is used up by neutralization of DCIPs. DCIP also should be rehabilitated.

• Asia pacific journal of information systems
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• 제33권2호
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• pp.418-443
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• 2023

Many organizations facilitate a host of online knowledge sharing communities to assist internal knowledge sharing and operation. The permeable boundaries and voluntary structures of online communities allow individuals to span community boundaries and affect member resources and structures. Although much research has been done on members' knowledge contribution in online communities, relatively little is known about how a member's contribution to a community is shaped by the cross-level interactions of member's external boundary spanning and the community's environmental scanning or membership fluidity. Drawing from the theoretical lens of boundary spanning and the external view of online communities, we take a multi-level approach in the analysis of the activities of 1,992 members of 126 communities internal to a global company. We find that a member's external boundary spanning activity (e.g., external knowledge acquisition via reading posts) has a positive effect, though at a decreasing rate, on subsequent internal knowledge contribution (e.g., posting replies in the member's home community). This positive effect is stronger in communities that are more active in environmental scanning or have fluid membership and weaker in communities that are less active in environmental scanning or have stable membership.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2002년도 춘계학술대회 논문집
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• pp.145-150
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• 2002

Tubular joints having a large diameter in the offshore structure are reinforced using internal ring stiffener in order to increase the load carrying capacity. In this study, the static strengths of internally ring-stiffened tubular T-joints subjected to compressive brace loading are assessed. Nonlinear finite element analyses are used to compute the behavior of unstiffened and ring-stiffened T-joints. From the numerical results, internal ring stiffener is found to efficient in improving the ultimate capacity, and reinforcement effect are calculated. The influence of geometric parameters for members and ring is evaluated. Based on the FE results, regression analysis is performed considering practical sizes of ring stiffener, finally strength estimation formulae for ring-stiffened T-joints are proposed.

• 지식경영연구
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• 제19권3호
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• pp.113-134
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• 2018

This study examines the roles of intangible and tangible resources of Korean business groups on internationalization by their member firms. Specifically, we argue that not all affiliates receive same benefit from group-level resource sharing. Instead, the effect of group-level knowledge sharing on affiliates' internationalization depends on individual affiliates' relative financial positions within a business group. Using samples of business groups in Korea, chaebols, hereafter chaebols, we find that foreign market knowledge at the group level has a positive impact on the internationalization of affiliated firms while the product knowledge has no impact. Furthermore, we also find evidences that an affiliate with high level of financial capacity receives internal pressures to stay in domestic market to secure internal capital market and support other sister affiliates' international activities.

• Mycobiology
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• 제40권4호
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• pp.255-257
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• 2012

Among 80 types of yeast isolated from wild flowers in Daejeon, Korea, two species that have not yet been identified by phylogenetic analysis of the internal transcribed spacer-2 (ITS2) genes and 26S rDNA sequences were identified as Candida sp. 44-C-1 and Cryptococcus sp. 9-D-1. Neither of the newly identified species formed ascospores, while Candida sp. 44-C-1 formed pseudomycelium and Cryptococcus sp. 9-D-1 did not.

• 한국보건간호학회지
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• 제31권1호
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• pp.121-134
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• 2017

Purpose: The goal of this study was to define and clarify the concept of "self management" of children with chronic diseases. Methods: For analyzing the concept of self management, this study used the hybrid model. This study involved in-depth interviewing nine children with chronic disease. Results: The concept of self management of children with chronic disease can be categorized with three dimensions: internal, environmental, and behavioral aspects. Besides, five attributes and thirteen indicators were analyzed. The concept of self management of children with chronic disease can be expressed as a kind of process; a) re-established yourself (internal dimension), b) assistance by the surrounded (environmental dimension), and c) positive health management behavior with self control of daily life (behavioral dimension). Conclusion: The self management is important for children with chronic disease to control their disease for long time. The attributes and indicators drawn by this study could be used for tool development and useful resources of self management competence in children with chronic disease.

• 아동학회지
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• 제18권1호
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• pp.39-52
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• 1997

This study focused on factors influencing Internal and external problem (depression and antisocial) behavior among late-elementary children. Subjects were 481 boys and girls enrolled in the fourth. fifth. and sixth grades of public school. The contribution of grade. sex. stress, self-esteem. and social support from parents, teachers, and friends as well as school performance were studied. The instruments were the Adolescent Perceived Events Scale, the Self-Esteem Scale, the Social Support Scale for Children, the Revised Korean Version of the Center for Epidemiologic Studies' Depression Scale and Antisocial Behavior Scale. Results indicated that sex, stress, self-esteem, and the support of parents, teachers and friends reduced the level of depression. Grade, sex, stress, self-esteem, and teachers' support were related to the level of antisocial behavior. The results were discussed in terms of the effects of stress, personal and social resources, and school achievement on depression and antisocial behavior.

• 한국시뮬레이션학회논문지
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• 제6권2호
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• pp.71-79
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• 1997

In this paper, operations system was designed for the centralization of data processing of various state information from the facilities of mobile communication network. And the system performance experimental system module was measured and analyzed from the designed experimental system module. The configuration of system design was presented with the centralized type to monite and control the facilities of mobile communication network in the central office. The communication process design of the internal system was implemented with the resource of message queue having a excellent transmission ability for processing of a great quantity of information in the inter-process communication among communication resources of UNIX system. The process with a server function from the internal communication processes was constructed with a single server or a double server according to the quantity of operations and implemented with the policy of the presented server. And then, we have measured performance elements in accordance with the change of input parameters from the designed experimental module : response time, waiting time, buffer length, the maximum quantity existing in message queue. And from these results, we have compared and analyzed the system state each server algorithm according to performance variations.

• 한국유체기계학회 논문집
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• 제18권6호
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• pp.31-36
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• 2015

A multi-stage turbocharger system has been constructed for HALE UAV internal combustion engine. To boost rarefied intake air up to sea level condition, the turbocharger system should consist of 3 stages including heat exchanger located after compressor outlet to drop compressed air temperature. One dimensional system analysis has been conducted by matching required power between compressor and turbine and adequate turbochargers have been searched for from commercially available models targeting for automobiles. By applying commercial automobile turbochargers to the multi-stage turbocharger system, it is expected that considerable amount of research resources will be saved.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 춘계학술대회 논문집
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• pp.76-82
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• 2001

The ASME B3l.4〔1〕and B3l.8 〔2〕codes use the thin wall formula to predict hoop stress in a pipe. To account for the external pressure, the above codes simply subtract the external pressure from the internal pressure. The thin wall formula using this differential pressure does not give the same hoop stress as the thick wall formula. This paper proposes an improved equation to predict pipe hoop stress subjected to both internal and external pressure. Compared to the conventional thin wall formula, the improved formula has additional terms, which improve the agreement with the thick wall formula and account for external pressure. The improved formula is less conservative than the conventional thin wall formula, but slightly more conservative than the thick wall formula. The formula is simpler and easier to use than the thick wall formula and will save pipe material cost as well as installation cost compared to using the conventional thin wall formula. The savings will increase as the water depth increases.