Purpose: To assess the prevalence of epilepsy in a rural district of Lao PDR and to describe the clinical and epidemiological profile of the disease. Methods: Door-to-door screening was performed on the entire population of 8 randomly selected villages in the Hinheub district, using an internationally validated and standardized questionnaire. Additional passive case detection was performed through village key informants. Suspected epilepsy patients identified by the questionnaire were revisited and examined by an experienced neurologist on two follow-up visits. The confirmation of epilepsy was based only on an in-depth clinical examination. Electroencephalograms were performed at the district health care center. Results: In the 8 villages, 277 suspected cases of epilepsy were identified among 4,310 interviewed subjects; 194 of whom (70%) underwent a clinical examination by a neurologist during the first visit while 65 of 83 remaining suspected cases were seen on the second confirmation visit. Twenty-seven persons with epilepsy were identified. Six additional patients were diagnosed in 219 self-referred subjects. An overall prevalence of 7.7 cases of epilepsy per thousand inhabitants was calculated (95% CI 5.3–10.7). Generalized epilepsy (21 cases, 63.6%) was commoner than partial epilepsy (9 cases, 27.3%). The remaining 3 cases (9.1%) were not-classifiable as either generalized or partial. EEG abnormal findings were found in 12 of the 24 patients (50.0%) who had an EEG registration. Conclusions: This is the first study in Lao PDR to estimate the prevalence of epilepsy. Compared to Western countries it shows a pattern towards a higher prevalence.

Ship motion is a complex controlled process with several hydrodynamic parameters that vary in wide ranges with respect to ship load condition, speed and surrounding conditions (such as wind, current, tide, etc.). Therefore, to effectively control ships in a designed track is always an important task for ship masters. This paper presents an effective adaptive autopilot for ships that ensure the optimal accuracy, economy and stability characteristics. The PID control methodology is modified and parameters of a PID controller is designed to satisfy conditions for an optimal objective function that comprised by heading error, resistance and drift during changing conrse, and loss of surge velocity or fuel consumption. Designing of the controller for conrse changing process is based on the Model Reference Adaptive System (MRAS) control theory, while as designing of the automatic course keeping process is based on the Self Tuning Regulator (STR) control theory. Simulation (using MATLAB software) in various disturbance conditions shows that in comparison with conventional PID autopilots, the designed autopilot has several notable advantages: higher conrse turning speed, lower swing of ship bow even in strong waves and winds, high accuracy of course keeping, shorter time of rudder actions smaller times of maneuvers' simulations have been carried out using MATLAB software to verify the effectiveness of the method, and excellent results achieved show remarkable advantages of the ship autopilot in comparison with other conventional autopilots such as PD or PID ones.The paper is organized as follows: The first Section gives the nature of the problems considered, previous works, purpose and contribution of this study as well as related research. The second Section presents the mathematical model used in this study to express ship steering motion. The model contains both linear and non-linear features of ship steering. Control algorithm used for the adaptive autopilot and designing issues are presented and discussed in details in the third Section. To verify the effectiveness of the adaptive autopilot, MATLAB software was used to simulate ship motion during several different maneuvers. Section IV gives simulation results, including comparison of the quality of a conventional PID autopilot and the adaptive autopilot. And finally, the fourth Section draws some conclusions form this study and points out some possible direction for father study. 11. MATHEMATICAL MODEL The mathematical model used to express ship motions in this study is as follows [4], [51, [61, [71, [SI, [91, [IO]: changing rudder direction. Kev worak: non-linear control. adavtive control. PID T,(drldt) + H , ( r ) = KJ + K:S .~ control, MRAS, STR, ship autopilot T,(duIdt) t H,(u) = K,r'

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