• 한국직업건강간호학회지
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• 제30권3호
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• pp.120-131
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• 2021

Purpose: This study aimed to compare the effects of an 8 week, self-managed, app-based and poster-based stretching program on musculoskeletal symptoms, flexibility, stretching frequency, self-efficacy, social support, and musculoskeletal disorder knowledge in small manufacturing business workers. Methods: This was a cluster randomized, two-group pretest-posttest design. Workers were assigned to either an app-based (n=20) or a poster-based (n=25) stretching intervention. Both groups received an educational class. The app group also received mobile phone text messages and an app with stretching videos, stretching alarms, stretching records, and information on musculoskeletal disorders. The poster group received workplace stretching posters. Data were collected from April to September 2018 and analyzed with the 𝑥² test, paired t-test, and independent t-test. Results: There was only a significant difference in social support. Significant increase in flexibility and musculoskeletal symptoms were noted for both groups, but social support and musculoskeletal disorder knowledge were significantly changed only in the poster group. More than half of the workers practiced stretching at least 3 times a week. Conclusion: The 8 week, self-managed, workplace stretching program was effective to increase flexibility and stretching frequency to at least 3 times a week. However, effective interventions for musculoskeletal symptoms could not be identified.

• Journal of information and communication convergence engineering
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• 제15권4호
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• pp.205-211
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• 2017

Combining dispersion-managed optical links with midway optical phase conjugation (OPC) is a possible method of compensating for optical signal distortion due to group velocity dispersion and nonlinear Kerr effects. Although an improvement in the performance of these optical links has been reported, the fixed residual dispersion per span (RDPS) that is typically used restricts the flexibility of link configurations. Thus, in this paper, a flexible dispersion-managed link configuration, comprising artificial distributions of linearly/nonlinearly incremented RDPS, is proposed. Simulations show that a descending distribution of RDPS before the midway OPC, and an ascending distribution of RDPS after the midway OPC, gives the best artificial distribution pattern as the number of fiber spans is increased, regardless of the RDPS incrementation method.

• Journal of information and communication convergence engineering
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• 제17권4호
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• pp.227-233
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• 2019

In long-haul optical communication system consisting of standard single-mode fiber spans and fiber amplifiers, such as the erbium-doped fiber amplifier, performance is deteriorated by signal distortion due to chromatic dispersion and nonlinearity of the fiber. A combination of dispersion management and optical phase conjugation is an effective technique to compensate for the distortion. In an optical link configured by this combination, a dispersion map mainly affects the compensation of the distorted optical signals. This paper proposes new dispersion maps configured by the decaying or expanding distribution of residual dispersion per span (RDPS) in a dispersion-managed link combined with a midway optical phase conjugator. The effect of the proposed dispersion maps on the compensation for distorted 24 channel × 40 Gbps wavelength-division multiplexed signals was assessed through numerical simulation. It was confirmed that all the proposed dispersion maps are most appropriate for the compensation and, furthermore, for the flexibility of link configuration than conventional links.

• 한국항행학회논문지
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• 제25권6호
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• pp.517-522
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• 2021

장거리 파장 분할 시스템을 위해 해결해야 하는 광 색 분산과 비선형 현상에 의한 광 신호 왜곡을 보상할 수 있는 광 위상 공액과 결합된 분산 제어 링크를 네트워크 토폴로지의 유연성 관점에서 제안하고 분석하였다. 비선형 효과에 의해 왜곡되는 광 신호의 보상을 위해 적용된 광 위상 공액기는 전체 전송로 중간이 아닌 곳에 위치시켰다. 그리고 광 위상 공액기를 중심으로 전반 전송 구획과 후반 전송 구획을 구성하는 각각의 중계 구간의 잉여 분산 (RDPS; residual dispersion per span)을 서로 다르게 한 분산 제어 링크를 적용하였다. 각 중계 구간의 RDPS가 전반 전송 구획과 후반 전송 구획의 전체 잉여 분산을 같게 만드는 값이 아닌 그 근처의 서로 다른 값으로 결정되어야 왜곡된 광 신호 보상에 효과적이라는 것을 시뮬레이션 결과를 통해 확인하였다.

• 산업노동연구
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• 제23권1호
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• pp.47-83
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• 2017

스웨덴 노동시장은 정규직 정리해고 대신 임시직 중심 비정규직 활용을 통해 노동력 사용의 유연성을 확보한다. 2000년대 후반 법개정으로 임시직 사용이 보다 더 용이하게 되었고 경제위기 발발로 자본의 힘의 우위가 강화되었음에도, 임시직 규모는 급증하지 않고 도리어 축소되었다. 본 연구는 임시직의 사용 실태와 사용방식 변화를 분석하며 법개정 효과와 경제위기 효과의 설명력을 검토하고, 임시직 등 비정규직 사용을 둘러싼 자본의 유연성 확보 전략과 노동의 유연성 규제 전략이 어떤 내용으로 추진되며, 어떻게 서로 각축하고 타협하며 경제위기 이후 비정규직 사용의 새로운 평형점을 형성하게 되었는지를 설명하고자 한다. 임시직 사용 규제를 완화한 법개정에도 불구하고 단체협약의 내용 수정이 수반되지 않음으로써 법개정 효과는 제한되었고, 경제위기를 거치며 사용업체들이 임시직 대신 간접고용 중심으로 인력을 확충하면서 임시직 규모는 도리어 감소하게 되었다. 사용업체들이 간접고용을 더 선호하게 된 것은 사용자로서의 책임을 회피하고 사용기간 제한 규정이 없어 무기한 사용할 수 있다는 장점 때문이었다. 자본은 경제위기를 거치면서 정규직 대 비정규직 비율을 80-20으로 유지하며 간접고용 비정규직을 '항구적 임시직'으로 사용하는 전략을 취하게 된 것이다. 이에 맞서 노동조합은 임시직보다 간접고용을 더 강력하게 규제하는 전략으로 대응함으로써 간접고용이 외적 수량적 유연성을 확보하기 위한 용도로만 사용되게 되었다. 그 결과, 파견노동을 넘어 임시직을 포함한 전체 비정규직의 사용방식에서도 '관리된 유연성'이 작동하게 되었다. 간접고용의 오 남용이 극심한 한국의 경우 스웨덴 노동조합의 전략처럼 간접고용 노동자에게 여타 고용형태들보다 더 확실하게 고용안정을 보장하고 높은 임금을 보장하는 사회적 개입이 절실하다.

• 복식문화연구
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• 제17권5호
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• pp.819-833
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• 2009

The current research focused on exploration of a well known Korean fashion and clothing industry cluster, Dongdaemun Fashion Town(DFT). Many clothing and fashion wholesalers in DFT with various business formats are trying to obtain competitive advantages. For the empirical study, a questionnaire was developed. Items measuring descriptive statistics for each business and contractor selection criteria were included in the survey. 161 data from Employees of various wholesalers of DFT were used for statistical analysis. Majority of DFT customers were buyers of Internet shopping malls and street retail shops. 64% of them used domestic contractors for sourcing products. Most of them managed less than three contractors. Contractor selection criteria were factorized as flexibility, production ability, stability, fame and location. Wholesalers were segmented into three groups: product oriented, flexibility oriented and stability oriented groups. Group differences in terms of business practices were assessed and strategic implications were included.

• International Journal of Contents
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• 제7권1호
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• pp.58-64
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• 2011

This paper is concerned with simulation exercises used to train key response agencies for crisis situations. While 'multi-agency' simulations are increasingly acknowledged as a necessary and significant training tool for emergency response organisations, many current crisis simulations are still focused on the revision of existing response plans only. However, a crisis requires a rapid reaction, yet in contrast to an 'emergency', the risks for critical decision makers in crisis situations are difficult to measure, owing to their ill-structure. In other words, a crisis situation is likely to create great uncertainty, unfamiliarity and complexity, and consequently should be managed by adaptive or second order expertise and techniques, rather than routine or structured responses. In this context, the paper attempts to prove that the current practices of simulation exercises might not be good enough for uncertain, unfamiliar, and complex 'crisis' situations, in particular, by conducting case studies of two different underground fire crises in Korea (Daegu Subway Fire 2003) and the UK (King's Cross Fire 1987). Finally, it is suggested that the three abilities: 'flexibility', 'improvisation' and 'creativity' are critical in responding to a crisis situation.

• 한국경영과학회지
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• 제39권4호
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• pp.153-165
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• 2014

We present a new framework for rental capacity management in which rental capacity is dynamically managed by means of temporary inventory addition/return. While serving customers with its own (native) capacity, the rental firm rents additional rental capacity from an upper echelon rental company so that it can avoid lost sales which may occur when stock is not sufficient, and returns it when stock becomes sufficiently large enough to cope with demands. Formulating the model as a Markov decision process, we investigate a flexible capacity addition/return policy that maximizes the firm's profit with respect to system costs. Numerical study indicates that rental operation with capacity addition/return can be economically favorable over rental operation without capacity expansion/return and can contribute the reduction in the size of native rental capacity.

• Journal of information and communication convergence engineering
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• 제12권2호
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• pp.75-82
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• 2014

Dispersion management (DM), optical phase conjugation (OPC), and the combination of DM and OPC are promising techniques to compensate for optical signal distortion due to group velocity dispersion and nonlinear Kerr effects. The system performance improvement in DM links combined with OPC has been reported; however, the fixed residual dispersion per span (RDPS) usually used in these links restricts the flexibility of link configuration. Thus, in this paper, a flexible optical link configuration with artificially distributed single-mode fiber (SMF) lengths and RDPS in the combination of DM and OPC is proposed. Simulation results show that the best artificial distribution pattern is the gradually descending distribution of SMF lengths and the gradually ascending distribution of RDPS, as the number of fiber spans is increased, regardless of the average RDPS, the optimal net residual dispersion, and the dispersion coefficient of the dispersion compensating fiber.

• 한국정밀공학회지
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• 제9권3호
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• pp.53-60
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• 1992

This paper deals with developing an Expert system for tool selection using knowledge base system approach, and its application. For the sake of building of knowledge base, the information from process through sensor, tool handbook and interview with expert are referrenced and managed. The system developed shows good application flexibility in providing the actual cutting process with the selection of tool(insert, holder) and cutting conditions(feed, speed, rake type, and so on), is found as a useful system for real-time machining process. The Expert system for tool selection is written in TURBO PROLOG ver. 2.0 for inference engine capability, and can be run in interactive mode for user friendliness. In order to apply the system developed in actual cutting process, more parameters should be considered and scrutinized, and the system should be further extended in modular basis.