• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.14 no.2
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• pp.15-22
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• 2018

As heat pump application has been extending to residential, commercial, and industrial fields, the heat pump should have many operation modes. It is required to optimize refrigerant charge amount at all operation modes in order to enhance the annual performance of heat pumps. In this study, the performance analysis of the heat pump which has cooling, heating, cooling-hot water, heating-hot water, and hot water modes was executed with the variation of refrigerant charge amount. As the refrigerant charge amount changed, the maximum COPs of the heat pump at different operation modes were changed within ${\pm}10%$. Therefore, it is highly recommended to select optimum charge amount for the heat pump based on the analysis of annual load for each operation modes.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05b
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• pp.1027-1032
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• 1995

To develop operation scenarios of KT-2 tokamak, 3 operation modes(OH, high ${\beta}$ and high bootstrap) deduced from zero dimensional steady-state power balance are examined with TSC(Tokamak Simulation Code) time-dependent transport .ode. Plasma profiles are evaluated self consistently during simulations and plasma shapes are maintained by feedback control on PF coil currents. Simulations show operation modes which are typical of KT-2 expected discharges are compatible with the KT-2 PF system design specifications[1].

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.11
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• pp.955-962
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• 2016

In recent years, there have been emerging needs for standardized software-based motion application development for better scalability and support for multiple operation modes for small quantity batch production. Although a software-based motion system provides a basis for constructing multiple operation modes on a machine, it is not easy to construct such systems without tools for defining multiple motion operation modes and standardized mode-change protocols. This paper proposes a motion recipe concept to overcome this problem; the concept includes the authoring of multiple motion operation modes using the PLCopen-compliant motion function blocks and communication protocols to trigger operation mode changes from an external interface. The motion recipe was implemented by extending an IEC 61131-3 compliant IDE called Beremiz, and the correctness of the motion recipe-based application behavior was verified on a real testbed.

• New & Renewable Energy
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• v.2 no.2 s.6
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• pp.23-27
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• 2006

The power split hybrid powertrain is considered to be one of the most prospective configuration for the hybrid electric vehicle (HEV). Toyota Prius, representing this type of vehicle, showed outstanding performances in fuel efficiency, emission reduction and acceleration. The excellence is largely due to the fact that it utilizes almost all operation modes of HEV. Those modes include ZEV (Zero Emission Vehicle) driving, idle stop, fuel cut-off, power assist, active charging, regenerative braking and so forth. In this paper, a few of the mode operations were simulated using AVL Cruise. Also, control logics to operate the powertrain in each mode were developed. The states of powertrain components were displayed and analyzed. By controlling the three components (engine, motor and generator), it was possible to run the powertrain in several hybrid operation modes.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.547-550
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• 2006

The power split hybrid power train is considered to be one of the most prospective configuration for the hybrid electric vehicle (HEV). Toyota Prius, representing this type of vehicle, showed outstanding performances in fuel efficiency, emission reduction and acceleration. The excellence is largely due to the fact that it utilizes almost all operation modes of HEV. Those modes include ZEV (Zero Emission Vehicle) driving, idle stop, fuel cut-off, power assist, active charging, regenerative braking and so forth. In this paper, a few of the mode operations were simulated using AVL Cruise. Also, control logics to operate the powertrain in each mode were developed. The states of powertrain components were displayed and analyzed. By controlling the three components (engine, motor and generator), it was possible to run the powertrain in several hybrid operation modes.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.1
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• pp.79-85
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• 2006

This attack requires an oracle which on receipt of a ciphertext, decrypts it and replies to the sender whether the padding is VALID or INVALID. In this paper we extend these attacks to other kinds of modes of operation for block ciphers. Specifically, we apply the padding oracle attacks to multiple modes of operation with various padding schemes. As a results of this paper, 12 out of total 36 double modes and 22 out of total 216 triple modes are vulnerable to the padding oracle attacks. It means that the 12 double modes and the 22 triple modes exposed to these types of attacks do not offer the better security than single modes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.7
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• pp.3608-3628
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• 2017

Several block cipher modes of operation have been proposed in the literature to protect sensitive information. However, different security analysis models have been presented for attacking them. The analysis indicated that most of the current modes of operation are vulnerable to several attacks such as known plaintext and chosen plaintext/cipher-text attacks. Therefore, this paper proposes a secure block cipher mode of operation to thwart such attacks. In general, the proposed mode combines one-time chain keys with each plaintext before its encryption. The challenge of the proposed mode is the generation of the chain keys. The proposed mode employs the logistic map together with a nonce to dynamically generate a unique set of chain keys for every plaintext. Utilizing the logistic map assures the dynamic behavior while employing the nonce guarantees the uniqueness of the chain keys even if the same message is encrypted again. In this way, the proposed mode called SPCBC can resist the most powerful attacks including the known plaintext and chosen plaintext/cipher-text attacks. In addition, the SPCBC mode improves encryption time performance through supporting parallelized implementation. Finally, the security analysis and experimental results demonstrate that the proposed mode is robust compared to the current modes of operation.

• Nuclear Engineering and Technology
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• v.53 no.9
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• pp.2859-2865
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• 2021

One of the important issues raised from the Fukushima-Daiichi accident is the safety of multi-unit sites when simultaneous accidents occur at the site and recently a multi-unit PSA methodology is being developed worldwide. Since all operation modes of the plant should be considered in the multi-unit PSA, the accident analysis needs to be performed for shutdown operation modes, too. In this study, a station blackout during the mid-loop operation is selected as a reference scenario. The overall accident progression for the mid-loop operation is slower than that for the full-power operation because the residual heat per mass of coolant is about 6 times lower than that in the mid-loop scenario. Though the fractions of Cs released from the core to the RCS in both operation modes are almost the same, the amount of Cs delivered to the containment atmosphere is quite different due to the chemisorption in the RCS. While 45.5% of the initial inventory is chemisorbed on the RCS surfaces during the full-power operation, only 2.2% during the mid-loop operation. The containment remains intact during the mid-loop operation, though 83.9% of Cs is delivered to the containment.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.480-483
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• 2001

Recent power quality measurement projects report that voltage sags are the most frequent disturbances in the sites [1]-[4]. DVRs were emerged as the best effective and economic solution for this problem [11]. This paper analyzed the power flow of a DVR in distribution grids. This paper showed various operation modes and boundaries such as inductive operation, capacitive operation, and minimal power operation beside the in-phase compensation.

• Journal of the Ergonomics Society of Korea
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• v.5 no.2
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• pp.3-9
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• 1986

The present paper deals with obtaining the proper application criteria for the control mode, by using computer graphic simulation, in order to recover the error effectively occurring in the practical supervisory contol work of hyman-robot system. In these experiments the opteations by human and by control program are performed as control modes for recovering the error. And then we compare and analyze tow control modes taking task error and task time as performance measures and task difficulty as a variable factor. Consequently as the task difficulty increases, the task error in the operation by hyman tends to be less than in the operation by control program and the task time is superior in the operation by control program. Therefore, we suggest that two control modes should be used jointly for recovering the error and the operation by control program should be applied in major fraction of control and the operation by human in minor fraction of control.