원자력 발전소에 설치되는 안전관련 기기의 손상은 심각한 사고로 이어질 수 있으므로 반듯이 지진안전성을 확보하여야 한 다. MCC, Switchgear, Inverter, Battery charger 등의 전기캐비닛은 대표적인 안전관련 기기이다. 대부분의 실험적 연구는 실험대 상기기의 크기와 실험장비의 성능한계 등으로 인하여 주요부품을 대상으로 하며, 실제 원자력발전소에 납품하는 전기캐비닛을 이용하 여 3축 동시가진에 의한 진동대 실험을 수행한 연구는 많지 않다. 따라서 실제기기를 대상으로 3축 진동대 실험을 통하여 내진성능과 한계상태를 직접적으로 평가하기 위한 연구가 필요하다. 이러한 한계상태평가의 주요 목적은 다양한 부품으로 구성된 캐비닛 단위 실 제기기의 임계 가속도 및 고장 모드를 조사하는 것이다. 본 논문에서는 3축 진동대 실험으로 한계상태 내진성능실험을 수행하여 원자 력발전소에 납품되는 것과 동일한 4종의 전기캐비닛들의 한계상태를 분석하였다.

Dynamic responses of nuclear power plant structure subjected to earthquake loads should be carefully investigated for safety. Because nuclear power plant structure are usually constructed by material of reinforced concrete, the aging deterioration of R.C. have no small effect on structural behavior of nuclear power plant structure. Therefore, aging deterioration of R.C. nuclear power plant structure should be considered for exact prediction of seismic responses of the structure. In this study, a machine learning model for seismic response prediction of nuclear power plant structure was developed by considering aging deterioration. The OPR-1000 was selected as an example structure for numerical simulation. The OPR-1000 was originally designated as the Korean Standard Nuclear Power Plant (KSNP), and was re-designated as the OPR-1000 in 2005 for foreign sales. 500 artificial ground motions were generated based on site characteristics of Korea. Elastic modulus, damping ratio, poisson’s ratio and density were selected to consider material property variation due to aging deterioration. Six machine learning algorithms such as, Decision Tree (DT), Random Forest (RF), Support Vector Machine (SVM), K-Nearest Neighbor (KNN), Artificial Neural Networks (ANN), eXtreme Gradient Boosting (XGBoost), were used t o construct seispic response prediction model. 13 intensity measures and 4 material properties were used input parameters of the training database. Performance evaluation was performed using metrics like root mean square error, mean square error, mean absolute error, and coefficient of determination. The optimization of hyperparameters was achieved through k-fold cross-validation and grid search techniques. The analysis results show that neural networks present good prediction performance considering aging deterioration.

It is likely to occur internal exposure for workers in Nuclear Power Plants (NPPs) due to the intake of radionuclide. To assess the internal exposure dose the measurement of activity for remain radionuclide is necessary. The Whole Body Counters (WBCs) are commonly used for measurement of remain radionuclide activity in human body. Korea Hydro & Nuclear Power Co., Ltd. (KHNP) conduct performance test of WBCs in all NPPs for every year to confirm the performance of equipment. The performance test is conducted using unknown sources and the participants of the comparison test submit the radionuclide and activity of the unknown sources measured by WBC as a result. The performance indicator and criteria for WBC recommended in the American National Standards Institute (ANSI) N13.30 report published in 2011 are applied. The performance indicator is Root Mean Squared Error (RMSE) and criteria is 0.25 or less. The results of performance test performed in 2022 for all WBC is meet the ANSI N13.30 criteria. And the RMSE values are confirmed from 0.01 to 0.23. This means that the residual radioactivity measurement results using WBC are reliable.

Sea trial tests are necessary to verify speed-power performance, and are an import contract between ship owners and shipyards. The International Organization for Standardization (ISO) published ISO 15016:2015, which specifies the correlation method between model and full-scale ships. The results of sea trials have been questioned because of the uncertainty of speed and power measurements, especially when sea conditions differ from ideal calm water conditions. In this paper, such uncertainties were investigated by utilizing the standard speed-power trial analysis procedure defined in ISO 15016:2015 through Monte Carlo simulations. It was found that the expanded uncertainty of the delivered power (PDid) at 95 % confidence interval (k = 2) was ±1.5 % under 75 % MCR conditions.

Analysis of the 2016 Gyeongju earthquake and the 2017 Pohang earthquake showed the characteristics of a typical high-frequency earthquake with many high-frequency components, short time strong motion duration, and large peak ground acceleration relative to the magnitude of the earthquake. Domestic nuclear power plants were designed and evaluated based on NRC's Regulatory Guide 1.60 design response spectrum, which had a great deal of energy in the low-frequency range. Therefore, nuclear power plants should carry out seismic verification and seismic performance evaluation of systems, structures, and components by reflecting the domestic characteristics of earthquakes. In this study, high-frequency amplification factors that can be used for seismic verification and seismic performance evaluation of nuclear power plant systems, structures, and equipment were analyzed. In order to analyze the high-frequency amplification factor, five sets of seismic time history were generated, which were matched with the uniform hazard response spectrum to reflect the characteristics of domestic earthquake motion. The nuclear power plant was subjected to seismic analysis for the construction of the Korean standard nuclear power plant, OPR1000, which is a reactor building, an auxiliary building assembly, a component cooling water heat exchanger building, and an essential service water building. Based on the results of the seismic analysis, a high-frequency amplification factor was derived upon the calculation of the floor response spectrum of the important locations of nuclear power plants. The high-frequency amplification factor can be effectively used for the seismic verification and seismic performance evaluation of electric equipment which are sensitive to high-frequency earthquakes.

이 연구의 목적은 파워 저항운동이 여성노인의 체력, 근육량 및 단기운동수행력에 미치는 영향을 보고자 하였다. 이 연구에 참여한 피검자는 70세 이상의 천안시 거주 여성노인 30명을 파워 저항운동군 15명과 일반 저항운동군 15명으로 분류하였다. 파워 저항운동군은 속도를 빠르게 하는 저항운 동을 일반 저항운동군은 평소속도의 운동을 주 3회 60분간 실시하였다. 연구결과 근력은 두 저항운동군에서 유의한 개선을 보였고, 전신지구력에서는 파워 저항운동군에서 유의한 개선을 보였다. 단기운동수 행력 중 2.44m왕복걷기는 파워 저항운동군에서, 400m걷기에서는 두 저항운동군에서 유의한 개선을 보이는 것으로 나타났다. 결론적으로 체력과 근량 및 단기운동수행력에서 두 운동방법의 효과는 충분하나 파워저항운동이 다소 우세한 것으로 나타났다.

리더와 구성원의 관계적 측면에서 리더십을 이해할 필요가 있다는 주장이 제기되고 있으며, 관계적리 더십으로써 포용적리더십이 주목받고 있다. 포용적리더십은 구성원과의 상호작용에서 개방성, 접근성, 이 용가능성을 보이는 리더로 정의된다. 최근 다수의 연구에서는 포용적리더십의 효과에 대해 관심을 가지고 실증하고 있다. 하지만 포용적리더십의 긍정적인 효과에도 불구하고 이론적 근거 및 메커니즘을 설명하는 연구는 아직 미흡하다. 또한, 리더십행동이 구성원의 태도와 성과에 영향을 미치는 정도는 상황요인에 따라 달라질 수 있으므로 포용적리더십의 효과를 보다 온전히 이해하기 위해서는 상황요인에 대한 탐색이 요구된다. 그러나 포용적리더십의 상황요인을 밝히는 연구는 드물다. 이에 따라 본 연구는 포용적 리더십과 구성원의 직무성과 간의 관계에서 권력거리의 조절효과를 실증하였다. 실증분석을 위해 국내의 다양한 기업에 근무하는 306명을 대상으로 수집한 설문응답 자료를 분석하였다. 실증결과는 다음과 같다. 첫째, 포용적리더십과 직무성과 간에 유의한 관계가 나타났다. 둘째, 포용적리 더십과 직무성과의 관계에서 심리적안전감의 매개효과는 유의한 것으로 나타났다. 셋째, 권력거리가 높을 수록 포용적리더십이 심리적안전감에 미치는 영향력이 강화되었다. 본 연구의 실증 결과를 바탕으로 이 론적, 실무적 시사점을 논의하였고, 연구의 한계와 향후 연구방향을 제시하였다.

In this study, the yaw misalignment value of wind turbine was measured using Lidar and it was analyzed the effect of vibration reduction and power performance improvement when applied to turbine. It was confirmed that the vibration of the main bearing and the gear box of the wind turbine was partially reduced. Also it was found that the output performance was improved when the wind speed was over 8m/s. As a result, it was also found that the annual energy production(AEP) was improved when the average annual wind speed of the wind farm was over 6m/s. Converted to AEP, the AEP improved about 1% and 4%, when the annual wind speed was 6m/s and 11m/s respectively, which resulted in an improvement of about 1~4% through the yaw misalignment correction of the wind turbine.

In this study, a motion control problem for the vessels towed by tugboats or towing ships on the sea is considered. The towed vessel looks like the barge ship, which is used for many purposes. In these vessels, basically, the power propulsion system is not installed but just towed by a towing vessel such as tugboats with ropes and wires. It means that the motions of towed vessel are basically dependent on the tracking route of towing boat. Therefore, in some cases, undesirable and unpredictable motions may be made by environmental factors such as wave, wind attack and so on. As a result, a collision accident with others may occur during maneuvering situation. Based on these facts, the authors try to encourage the steering performance of the towed vessel by using controllable rudders without any propulsion system. In this study, especially, a controllable vessel with three rudders is considered, and a mathematical model is induced for the future study. The model is described as surge, sway motion and inertia moment by following the general representation method for the surface ship.

In this study, we have defined measurement and verification methods and procedures to assess the energy use on the utility system of building. Time series data conversion methods and algorithms have been proposed in performance evaluation options. To verify the feasibility of the method, the energy consumption of the refrigerator, which was an energy utility, was measured and analyzed. we present an algorithm based on the annual base conversion and analyze it based on actual data. As a result, a k-means clustering moving average method was defined for the performance calculation option A, and the use time correction coefficient method was proposed. The validity of this method was verified through the verification.

지역 밭작물 생산의 생력화를 제고하기 위하여 개발한 복합 작업기(BG-1200AB)를 트랙터(DK753C:55kW)에 장착하고 평두둑 복합기의 작업동력 및 견인력을 평가하였다. 견인 동력계의 여섯 로드셀에서 측정된 신호는 분력식에 따라 견인력(Ph), 수직력(Pv) 및 수평력(Ps)으로 계산되었고 각축에 생성되는 모멘트(Mh, Mv, Ms)를 계산하여 작업상태를 분석하였다. 견인력은 주로 토양의 다짐상태에 따라 영향을 받으며 평균 108-578kgf의 견인력에 대하여 견인동력은 0.5~0.9kW 정도였다. 작업속도는 0.4~2.0km/h 범위에서 절단피치가 증가할수록 비견인력(specific draft)이 감소하는 감소지수 관계를 보였다. PTO 토크는 경심에 따라 평균 160~350N․m으로 측정되었으며, 로터리 경운과 펌프 구동에 사용되는 PTO동력(9.0~19.8kW)이 소비동력의 대부분을 차지하였다. 따라서 복합기의 운용은 견인 동력효율에 맞춰져서는 이점이 나타나지 않으며 작업결과의 질 즉, 파종상토와 멀칭작업의 품질에 초점이 맞춰져야 한다. 상부견인 또는 하부견인에 따라 부하의 위치와 크기가 변화되고 작업기의 균형이 결정되므로 작업기의 고품질 작업을 추구하기 위하여 하부 링크의 독립적 제어를 제안한다.

Introduction In the past study, the relationship between the power structure of marketing and research and development (R&D) and NPD performance was not consistent (Atuahene-Gima & Evangelista, 2000; Engelen & Brettel, 2012; Li & Atuahene-Gima, 1999, 2001). The inconsistency may result from each study in different industrial contexts. It reflects every NPD project faces different environmental uncertainties. Furthermore, we adopt the external control perspective to glue power structure and NPD performance under a certain external environment together. Therefore, this paper tends to fulfill the gap of prior study, and the main objective of this research is to investigate whether the power structure of marketing and R&D functions have different linear relationships under the different level of environmental uncertainty. A NPD team is like a cross-functional organization that the NPD team is composed of multiple functions, and it has independent budgets. The members in the team will allocate their limited resources like budgets or positions to respond environments and to maximize profits. Theoretical Development When a NPD team faces the high market uncertain situation, marketing function can gather more resources because of its own power. Thus, R&D members in a NPD team may have less determination in the process of NPD. Even though they create a new product, marketing specialists make most decisions in the NPD team. According to function’s contribution argument, the more contribution of a certain function to the NPD process, the more positive related to the new product success (Atuahene-Gima and Evangelista, 2000; Atuahene-Gima and Luca, 2008; Li and Atuahene-Gima, 1999). Therefore, the current study proposes the hypothesis1 described below: H1: Market uncertainty will strengthen the relationship between power structure leaned to marketing and NPD successes. When a NPD team encounters the fast technological change situation, R&D function has more resources because of power. New product teams, however, usually have scare resources, so that another important function like marketing will have fewer resources than R&D function. Thus, marketers in a NPD team may have less determination in the process of NPD. The marketers may have some influence on launch stage like sales and promotion or distribution channels (Hsieh et al., 2008), but R&D specialists make most decisions in a NPD team. Therefore, the current study proposes the hypothesis2described below: H2: Technological uncertainty will strengthen the relationship between power structure leaned to R&D and NPD successes. Eisenhardt and her colleagues indicated that the organizations in high velocity environments have better performance when they decentralize the power structure (Eisenhardt, 1989; Eisenhardt and Bourgeois, 1988). They also described that this firm tended to introduce a new product line, and that its channel partners were fighting with each other by price wars but the dominant marketing function did not have enough time to perform its regular job. To maintain its power and resources, the dominant function may highlight its importance, so it will withhold external information and enable other members to perceive the external environment what dominant function expect them to perceive. When organizations find a lot of environmental changes, it is too late. Therefore, in the beginning organizations adopted decentralized power structure, and allocated resources equally. The members in organizations may not snatch resources, so they may not take political actions also. For the specialists in new product development team, they could not control their unique knowledge to withhold the information and to satisfy their own self-interests. Therefore, the relationship between marketing and R&D power distribution in a NPD team and new product financial performance is weakened in high velocity environments (Eisenhardt and Bourgeois, 1988). The hypothesis3 in the current study is below: H3: the relation between the power distribution in new product development teams and new product development successes is inverted U curve under the high technological and market uncertainty. Coping environment could rely on top manager’s backgrounds like marketing, technology or finance (Hambrick and Mason, 1984). To maintain the status of the dominant function, the dominant function will lead the organization to identify the important problems related to its function. In order to ensure keeping their power, moreover, the dominant function could institute some regulations or create norms. According to resource dependence perspective, if an organization has higher the formalization of power, the dominant function could gather more resources because of legitimacy. Further, the higher formalization of power may strengthen the relationship between power distribution and performance. Thus, our hypothesis 4 is below: H4: Under the higher formalization of power in a new product development team, the stronger relationship between the marketing and R&D power distribution and new product performance than under the lower degree of formalization of power situation. Research Design The current study used questionnaire survey and purposive sampling method to collect data. In order to eliminate the bias of common method variance (CMV), this study conducted multiple sources including project managers, the member charging marketing, and the member charging R&D to administrate questionnaires differently. In order to avoid selection bias, this study, moreover, asked the informants select the most recent new products developed and launched for minimum of twelve months. We sent three types of questionnaires to project managers, the member charging marketing, and the member charging R&D respectively. The current study sent questionnaires to 112 firms, and 69 firms are returned. The response rate is 61.61%. At new product level, there are 207 new product projects, and 100 firms are returned. The response rate is 48.31%. We also do tests of bias due to nonresponse which were conducted by using a comparison of early to late respondents’ all variable means (Armstrong & Overton, 1977). No evidence of a bias was found. The current study applied Moorman’s (1995) operationalization of new product performance is that the extent to which the product has achieved the objective of market share, sales, return on assets, profit margin, and return on investment during the first 12 months of its life in the marketplace. These items were used a 7-point Likert scale where 1 was “low” and 7 was “high”. This research adopted Homburg et al. (1999) scale to measure the power structure between marketing and R&D functions by using 100-point constant-sum scale for each NPD issue, and other previous studies also used issue-based perceptual power scale (Enz, 1989; Hinings et al., 1974; Pfeffer, 1981; Verhoef and Leeflang, 2009). The current study adopted Jaworski and Kohli’s (1993) scale to measure market and technological turbulence. The items were used a 7-point Likert scale where 1 was “extremely disagree” to 7 was “extremely agree”. In order to rule out other effects, we controlled industrial category, firm age, the number of marketing and R&D members involved in the NPD process, environmental hostility. Result and Conclusion The first finding is that under low market uncertainty and high technological uncertainty, balance of power structure tends to swing to the side of R&D function, and achieve better in NPD performance. Take IC design of High-tech industry as an instance, NPD project ends to perform better when the balance of power structure swing to the side of R&D function. The second finding is that under high market uncertainty and low technological uncertainty, NPD formalization helps to strengthen the relationship between marketing and NPD performance. Take frozen dessert in the food industry or leisure and sports fabrics in the textile industry as examples, formalization of NPD process can help marketing-driven NPD projects perform better in market. These findings advanced the understanding of the relationship between the power structure of marketing and R&D and NPD performance, rather than focusing on a single function, marketing or R&D. Furthermore, examining the relationship between the power structure of marketing and R&D and NPD performance in different environment uncertainty situations explained the inconsistency of the relationship between the power structure of marketing and R&D and NPD performance in past studies. Finally, this research conditionally supported the moderating effect of NPD formalization on the relationship between the power structure of marketing and R&D and NPD performance, and this exploration never been found.

In order for the probe to perform ocean exploration and survey research, it is necessary to adjust the position of the ship as desired by dynamic positioning system. The dynamic positioning system of T/S NARA is applied to K-POS dynamic positioning system of Kongsberg, which makes maintaining the ship's position, changing position and heading control possible. T/S NARA is not capable of dynamic positioning if one or more propulsive forces are lost with DP Level One. However, it is predicted that dynamic positioning can be achieved even at the time of missing one thrust in a good sea condition. Therefore, we want to analyze the effect of each propulsion on the performance of dynamic position system. When one of the bow thruster and azimuth thrusters lost their propulsion, maintaining the ship's position, changing position and heading control performance were compared and analyzed. If the situation occurred disable from using the bow thruster, they can not maintain ship's position. Azimuth thruster was influential for the ship's position control and bow thruster was influential in heading control. The excellent dynamic positioning performance can be achieved, considering the propulsion power that will have a impact on each situation in the future.