Development of prototype at data security through secret messages is needed for disguising the messages sent in smartphone chatting application, WhatsApp (WA) Chat. We propose a model to disguise a plaintext message which is first encrypted by cryptosystem to change the plaintext message to ciphertext. Plaintext or plainimage entering the smartphone system is changed into encrypted text; receiver then can read the message by using similar key with the sender. The weakness of this proposal is the message random system is not planted directly in the chatting application; therefore message removing process from cryptosystem to WA application is still needed. The strength of using this model is the messages sent will not be easily re-encrypted by hacker and can be used at client computing section.

Employees who are placed according to their knowledge, skills, and abilities tend to have high motivation, so the resulting performance will also increase. To ensure the right person or employee in the right position too, employee selection has always been a very important part of the company organization, especially in high schools. The decision-making process for promotion of promotion can be completed with a decision support system used by managers as a support for information in solving problems to fill positions, where the performance function can calculate the consideration of each competency possessed by each HR. DSS can provide alternative solutions when a person or group of people is difficult to make the right and appropriate decision. DSS is not to replace the function of decision-makers in making decisions, but only as a tool for decision-makers in carrying out their duties. THE fuzzy AHP method is able to determine the weight with the comparison value of each criterion, and this model Fuzzy-AHP method can cover the limitations of the AHP method, namely imprecision in overcoming Multi-criteria decision making which has subjective criteria. With this method approach, the ranking results of the determination of the position are obtained in accordance with the preferences of the decision-maker

In a corporate organization, human resources are a very important element to support progress and quality in achieving the goals of the company. The most important thing that can be done by the company, namely the employee selection process, in order to guarantee the right candidate in the right position as well. In this study, we will discuss the methods that can be applied in the career path process in an organization. Problems that often occur, such as being difficult to determine the right person to fill a position, mistargeting in the promotion process, because it is only judged from several criteria, then promotions are less transparent and not objective. By implementing a group decision support system (SPKK), where the opinions of several decision makers can be accommodated, as well as in problem solving and communication occurs in a group. This study uses the profile matching method, because it can provide an assessment of the potential of each employee candidate by comparing the employee's personal profile with the profile of the position in question, combined with fuzzy logic so that the original value obtained by the alternative remains consistent from the beginning to the ranking process. The results obtained in the form of ranking reports using the borda method, based on calculations from the fuzzy profile matching method, are expected to help company organizations to facilitate the promotion process.

PDAM Loa Kulu Branch still uses sticks or poles as an indicator of the water level in the reservoir. Reservoir is a place to store clean water production from PDAM, the weakness of using sticks or poles is when the operator does not monitor continuously causing air loss when production becomes large. The goal of the study was to design a water-level prototype to control excess water in the reservoir. The method used is a prototype with the stage of gathering information through interviewing PDAM staff, creating and repairing prototypes and testing prototypes. The test used hardware consisting of Arduino uno r3, ultrasonic sensor hc-sr04, flowmeter sensor yf-s201, 16 x 2 lcd, relay module, buzzer, solenoid valve 12 V_dc, pump 12 V_dc and display measurement results in the visual studio application 2019. Our findings are that the length of reservoir charging with an average input discharge of 3.6 liters / minute is 2.93 minutes. As for the length of emptying the reservoir with an average output discharge of 1.06 liters / minute is 12.10 minutes. The conclusion of this study is that the system can monitor the water level inside the reservoir automatically and know the time needed for the feeling and emptying process of the reservoir.