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"Measurement mostly required a precision, accuracy and sensitivity. Measurement by using the analog altimeter often shows that the obstained data are inaccurate, because lot of error factors influencing the measurement. To reduce the error factors, the altimeter is made digitally. Digital altimeter based on microcontroller AT89S53 is a measuring device that is designed to maesure relative or absolute altitude. This measuring instrument can be realized by using the atmospheric pressure sensor type MPX4100, voltage divider circuit, ADC 16 bits type AD7715 with serial control , microcontroller AT89S53 and LCD. The place for retrieving altitude data are selected randomly. From the result of testing and analyzing, this device produced the altitude measurement with average level of measurement error kurang lebih 0,367% average value level of measurement accuracy is equal to 99,6 % and the average of deviation kurang lebih 1,4 m at interval 100 m - 1180 m."

"Latar Belakang: Waktu Reaksi adalah suatu pengukuran kecepatan reaksi, suatu proses mental dari pengaliran rangsang di dalam sel-sel otak dan saraf, sering digunakan untuk menilai kemampuan pelaksanaan tugas mental seseorang. Berkurangnya suplai oksigen, terutama dalam jaringan otak dan saraf oleh pengaruh hipoksia akan memperpanjang waktu reaksi seorang penerbang dalam misi penerbangan. Keadaan ini merupakan faktor utama meningkatnya risiko terjadinya kecelakaan dalam misi penerbangan. Metodologi: Penelitian ini adalah suatu eksperimen kuasi dengan desain pra dan pasca tes terhadap 64 orang calon siswa sekolah penerbangan TN1 Angkatan Udara dengan usia 21-26 tahun. Kadar hemoglobin, saturasi oksigen, fungsi kardio respirasi, kadar gula darah, dan waktu reaksi di ketinggian permukaan diukur. Subyek diintervensi ke ketinggian simulasi 18.000 kaki dalam ruang udara bertekanan rendah untuk mencapai kondisi hipoksia, yaitu dengan nilai saturasi oksigen 64-72%. Dilakukan pengukuran waktu reaksi di ketinggian permukaan dengan waktu reaksi di ketinggian simulasi 18.000 kaki. Hasil: Terjadi pemanjangan waktu reaksi yang signifikan di ketinggian simulasi 18.000 kaki. (100.11 mdet ± 15,76) dibandingkan dengan waktu reaksi di ketinggian permukaan (90.98 mdet ± 14.53) (p < 0.05). Pemanjangan waktu reaksi ini disebabkan oleh berkurangnya kecepatan pengaliran rangsang di dalam jaringan otak dan saraf akibat berkurangnya suplai oksigen. Kadar hemoglobin mempunyai hubungan yang kuat dengan terjadinya pemanjangan waktu reaksi ini. Kesimpulan: Hipoksia pada ketinggian simulasi 18.000 kaki menyebabkan pemanjangan waktu reaksi.

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The Effect of Hypoxia on Reaction Time Among Indonesian Military Pilot's Candidates at a Simulated Altitude of 18.000 feet in the Hypobaric Chamber, 1999Background: Reaction time is a measure of the speed of reaction, it's a mental process that results from the impels processing through brain and nerves. It is often used to assess the ability of mental tasks performance. The lack of oxygen supply especially in the brain and nerves through hypoxia will prolong reaction time of the pilot which is a main factor to increase the risk of catastrophic in the flight mission.

Methodology: A quasi experiment study with a pre and post test design on 64 Indonesian Military Pilot's candidate's age 22-26 years was conducted. Hemoglobin, oxygen saturation, cardio respiratory function, blood sugar and reaction time at ground level was measured. Subjects were exposed to a simulated altitude of 18.000 feet for hypoxia condition in the hypobaric chamber. Hypoxia condition was indicated by 65-72% oxygen saturation. Reaction times at ground level and at 18.000 feet were measured.

Results: Reaction time was significantly longer at 18.000 feet (100.11 m sec ± 15.76) compared to ground level (90.98 m sec ± 14.53) (p < O.05). Prolonged reaction time at 18.000 feet is due to decrease of the speed of mental process in brain and nerves caused on reduced oxygen supply. Hemoglobin level showed strong correlation with prolonged reaction time (p-0,000).

Conclusion: Hypoxia at a simulated altitude of 18.000 feet prolonged reaction."

"ABSTRAKLatar belakang:Penelitian terdahulu mengenai pengaruh hipoksia terhadap penglihatan warna masih kontroversial. Penglihatan warna penting dalam penerbangan. Tujuan penelitian ini adalah untuk mengetahui pengaruh hipoksia setara 18.000 kaki melalui ruang udara bertekanan rendah terhadap penglihatan warna. Studi dilakukan di Lakespra Saryanto Jakarta pada bulan Desember 1996. Sampel terdiri dari 101 orang laki-laki, calon penerbang sipil PLP Curug, berusia 17-23 tahun dan tamat SLTA. Disain penelitian kuasi eksperimen pre dan post test. Diperiksa faktor-faktor faali seperti: nadi, tekanan darah sistolik dan diastolik, rib dan kadar saturasi oksigen darah. Digunakan buku Ishihara 38 lembar untuk pemeriksaan penglihatan warna dengan cara menilai waktu baca lembar 1-38 (detik) dan kebenaran baca lembar 1-21 (9i).Hasil penelitian :Melalui uji t berpasangan, ditemukan perbedaan bermakna (p<0,05) antara: saturasi 02 darah, nadi, waktu baca dan kebenaran baca pada permukaan tanah dibanding pada 18.000 kaki. Pada 18.000 kaki: kadar saturasi 02 darah 68,17 % ±2,92 lebih rendah dibanding pada permukaan tanah; nadi 116,32 ±12,21 permenit lebih tinggi dibanding pada permukaan tanah; waktu baca 72,18 ± 15,05 detik rata-rata lebih lama 15,52 detik dibanding pada permukaan tanah; kebenaran baca 97,43 ± 3,36% lebih rendah dibanding pada permukaan tanah. Studi ini menunjukkan bahwa waktu baca dan kebenaran baca buku Ishihara pada permukaan tanah maupun pada 18.000 kaki masih dalam batas normal. Analisa multiple regression dan simple regression menunjukkan bahwa diramalkan waktu baca lebih singkat apabila tekanan diastolik lebih besar pada permukaan tanah diramalkan waktu baca lebih singkat apabila denyut nadi meningkat.KesimpulanStudi penjajagan ini menunjukkan bahwa hipoksia setara 18.000 kaki meningkatkan waktu baca dan meningkatkan skor kesalahan baca tetapi tidak menyebabkan defisiensi penglihatan warna. Dibutuhkan penelitian lanjut dengan alat pemeriksaan warna yang lain untuk membandingkan studi ini.

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ABSTRACT

Back ground :

Related previous studies indicated the controversial result on the relationship between hypoxia and color vision. Color vision is one of the major individual factors for pilots which relates to many aircraft accidents especially in hypoxia condition. This study aimed to identify the relationship between color vision and the hypoxic hypoxia among pilot candidates in a hypobaric chamber at the cruising altitude of 18.000 ft (FL 180). The number of samples collection are 101 pilot candidates from PLP Curug, ages 17-23 yr. The design of study was a pre and post test and Ishihara plates were used to measure color vision.

Results .

A t-paired test analysis showed the significant differences (p< 0,05) among variables : pulse, oxygen saturation levels, reading time and error scores at ground level (GL) and at flight level of 18.000 ft (FL180). At 18.000 ft, study results reported : increased of pulse rate (mean 116 ± 12,21 per minutes), increased of SaO2 (mean 68,17% ± 2,92%), increased of reading time (72,18 } 15.05 seconds) and increased of error scores {41,58%). Multiple regression and simple regression analysis showed that increasing of diastolic at GL would decrease reading time and increases of pulse rate. At FL 180 would decrease reading time.

Conclusions:

This preliminary study indicated, that there was an increase of reading time and increase of error scores by using Ishihara plates at FL 180 but these results had not made a deficiency of color vision. Advanced study with any other device to examine color vision are needed to compare the result of preliminary study."

"A new means for providing wireless communication has been currently proposed. It is based on aerial vehicle known asHigh Altitude Platform or Stratospheric Platforms (SPF). The SPF will be operated at an altitude of 17-22 km above theground. Therefore, the channel condition may be different compared with those of the conventional terrestrial orsatellite wireless channel. In this paper, the channel propagation characteristic of such a system is firstly investigated bymeans of ray tracing algorithm. We emphasize our investigation in a typical urban environment, in which the mobileusers mostly exist. We developed building block model for simulation based on building height distribution, which isobtained from measurement inside Tokyo. As a result, propagation loss model and Ricean channel parameter for theSPF channel is reported in different scenarios. By using this result we then estimate the required transmitted power ofSPF to serve the mobile users in a several transmission rate that is used in IMT-2000 services. Finally, an evaluation ofBER of IMT-2000 link is performed in order to estimate the system level performance. From this evaluation, the maincontribution of this paper is to clearly show the critical limitations of both power requirement as well as system levelperformance of mobile communication IMT-2000 by using the concept of the SPF."

"This paper presents trajectory shaping of a surface-to-surface missile attacking a fixed with terminal impact angleconstraint. The missile must hit the target from above, subject to the missile dynamics and path constraints. Theproblem is reinterpreted using optimal control theory resulting in the formulation of minimum integrated altitude. Theformulation entails nonlinear, two-dimensional missile flight dynamics, boundary conditions and path constraints. Thegeneric shape of optimal trajectory is: level flight, climbing, diving; this combination of the three flight phases is calledthe bunt manoeuvre. The numerical solution of optimal control problem is solved by a direct collocation method. Thecomputational results is used to reveal the structure of optimal solution which is composed of several arcs, each ofwhich can be identified by the corresponding manoeuvre executed and constraints active."

"Latar belakang: Kondisi hipoksia hipobarik intermiten sering digunakan pada pelatihan, sehingga menyebabkan tubuh kekurangan oksigen pada saat tertentu atau disebut sebagai kondisi hipoksia. Hal ini dapat memengaruhi jaringan otot karena otot merupakan salah satu organ yang bergantung pada ketersediaan oksigen untuk menghasilkan ATP. Tubuh akan melakukan berbagai mekanisme kompensasi untuk mempertahankan keadaan homeostasis melalui pengaturan HIF-1α. HIF-1α akan meregulasi banyak ekspresi gen, salah satunya adalah enzim glikolitik yang mengatur metabolisme jaringan. Laktat dehidrogenase merupakan salah satu enzim glikolitik yang diatur oleh HIF-1α dan banyak ditemukan di otot sehingga diduga aktivitas enzim laktat dehidrogenase meningkat dalam kondisi hipoksia.Tujuan: Menganalisis aktivitas enzim laktat dehidrogenase pada otot tikus yang diinduksi hipoksia hipobarik intermitenMetode: Menggunakan uji eksperimental pada 5 kelompok tikus Wistar, yaitu normoksia, hipoksia 1 kali, hipoksia 2 kali, hipoksia 3 kali, dan hipoksia 4 kali. Hipoksia dilakukan selama 5 menit dalam hypobaric chamber dengan interval 7 hari. Biomarker hipoksia yang diukur adalah aktivitas enzim laktat dehidrogenase menggunakan LDH activity assay kit Elabscience.Hasil: Aktivitas spesifik enzim LDH dalam keadaan normoksia (1167,625±120,769 U/gprot), hipoksia 1 kali (1364,17±176,538 U/gprot), hipoksia 2 kali (911,218±130,305 U/gprot), hipoksia 3 kali (1069,153±121,685 U/gprot), dan hipoksia 4 kali (1085,814±52,314 U/gprot). Hasil ini menunjukkan tidak terdapat perbedaan signifikan antar kelompok (p>0,05).Simpulan: Tidak ditemukan adanya perbedaan aktivitas enzim laktat dehidrogenase antara kondisi normoksia dan hipoksia hipobarik intermiten

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Background: Condition of intermittent hypobaric hypoxia is often used in training, this condition can cause lack of oxygen at certain times or is known as a hypoxic condition. This can affect the muscle, because muscle is one of the organs that needs oxygen to produce ATP. The body will perform various compensatory mechanisms to maintain the homeostatic state through HIF-1α regulation. HIF-1α will regulate many gene expression, one of which is a glycolytic enzyme that regulates tissue metabolism. Lactate dehydrogenase is one of the glycolytic enzymes that is regulated by HIF-1α and is found in many muscles so that it is suspected that the lactate dehydrogenase enzyme activity increases in hypoxic conditions.

Aim: to analyzed the activity of the enzyme lactate dehydrogenase in rat muscle induced by intermittent hypobaric hypoxia

Methods: Using experimental tests on 5 groups of Wistar rats, divided to normoxic group, one-time hypoxia group, two-times hypoxia group, three-times hypoxia group, and four-times hypoxia group. Hypoxia was performed for 5 minutes in a hypobaric chamber with 7 days interval. Hypoxic biomarker measured was the activity of the lactate dehydrogenase enzyme using the LDH activity assay kit Elabscience.

Results: Specific activity of the LDH enzyme in normoxic group (1167,625±120,769 U / gprot), one-time hypoxia group (1364,17±176,538 U / gprot), two-time hypoxia group(911,218±130,305 U / gprot), three-times hypoxia group (1069,153±121,685 U / gprot), and four-time hypoxia groyp (1085,814±52,314 U / gprot). These results indicate that there is no significant difference between groups (p> 0.05).

Conclusion: There was no difference in the activity of the enzyme lactate dehydrogenase between normoxia and intermittent hypobaric hypoxia"

"Manusia sangat peka terhadap kekurangan oksigen, terutama pada susunan syaraf pusat, maka penerbang yang melakukan terbang pada ketinggian 18.000 kaki tanpa menggunakan oksigen tambahan akan mengalami hipoksia, dan penurunan daya ingat jangka pendek ( DIJP ). Untuk meningkatkan keamanan terbang, maka dilakukan penelitian terhadap 134 penerbang TNI AU yang sedang melaksanakan Indoktrinasi dan Latihan Aerofisiologi di Lakespra Saryanto. Penelitian ini menggunakan desain eksperimen laboratorium tanpa kontrol, yaitu dengan memajankan subyek di dalam simulator ruang udara bertekanan rendah ( RUBR ) yang setara dengan 18.000 kaki selama 20 menit. Sebelum dilakukan pengambilan data DIJP di dalam RUBR, semua subyek diperiksa dan diseleksi untuk persyaratan penelitian dan terbang dengan RUBR. Di dalam RUBR subyek diminta untuk mengerjakan soal-soal tes psikologi digit simbol sebanyak 20 lembar, dengan waktu satu menit setiap lembar, kemudian di lanjutkan ke lembar berikutnya, sehingga di dapatkan nilai kasar, yang kemudian di standarisasi dengan z score pada setiap lembarnya, hasilnya dianalisis dengan variabel umur, tekanan darah, Indeks masa tubuh (IMT), kadar hemoglobin, kadar gula darah, denyut jantung dan faal paru (FVC dan FEV1). Hasil dan Kesimpulan : Setelah dilakukan standarisasi, didapatkan nilai rata-rata DIJP 51,91 %, simpang baku 20 %, koefisien variasi 38,53 % ( dengan uji K-S for normality, program SPSS versi 4 didapatkan 2-tailed p = 0,573 jadi sebaran nifai DIJP masih sesuai dengan kurve Gause). Antara DIJP dengan umur mempunyai korelasi negatip, bermakna ( r = - 0,221; p = 0,005 ), berarti makin tua umur, maka DIJP semakin menurun. Antara DIJP dengan IMT mempunyai korelasi negatip, bermakna ( r = - 0,1799 ; p = 0,019 ), makin tinggi IMT semakin menurun kemampuan DIJP. Antara DIJP dengan Hb mempunyai korelasi positip, bermakna ( r = 0,165 ; p = 0,028 ), berarti semakin tinggi kadar Hemoglobin semakin baik DIJP. Sedangkan antara DIJP dengan variabel lainnya tidak bermakna, tetapi meskipun demikian sesuai dengan teori disebutkan bahwa meskipun tidak bermakna belum tentu tidak ada buhungan antara variabel tersebut dengan DIJP, mungkin mempunyai hubungan ( korelasi) yang sangat lemah.

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Human being is very sensitive to oxygen leak condition, especially on central nerves system. Hypoxia and decreasing of short term memory (STM) will affect the pilot who flight at the height of 18.000 feet without extra oxygen. The study was done to 134 Indonesian Air Force pilot to increase the flight safety. The study design is a laboratory experiment without control. Subjects were exposed for 20 minutes inside the chamber at simulated altitude of 18.000 feet height, after they passed physical examination and selection for " chamber flight " requirement. In the chamber subjects were requested to fill twenty sheets digit symbol physiological test for one minute per sheet. The result were standardized into z score for each sheet. The results were analyzed with age variable, blood pressure, Body mass index (BMI), Hemoglobin (Hb), blood sugar concentration, hart rate and respiratory systems (FVC and FEV1), to see whether the association exist.

Result and conclusion : The average of STM is 51,91 %, with 20 % of standard deviation, with K -S for normality test using SPSS program version 4 the STM distribution followed the Gauze curve. A negative correlation was found significant between STM with age, that more older the subject, STM will decrease ( r = - 0,221 ; p = 0,005 ). There is also a negative correlation and significant result between STM with BMI, means more higher BMI will decrease the STM ( r = - 0,1799 ; p = 0,019) Between S T M and Hb have significant and positive correlation, means more higher Hb the better the STM (r= 0,165 ; p = 0,028 ), and there is no correlation between STM and the other variables, but as theoretical said, even though there is no correlation with STM, it does not mean that there is no association between these variables with STM, but it is too weak to notice."

"Quadrotor adalah wahana yang memiliki empat buah rotor sebagai penggerak. Untuk dapat bergerak sempurna maka quadrotor harus dilengkapi dengan Sistem kendali yang mampu mangatur dan memberikan sinyal kendali berupa kecepatan motor keseluruh rotor.Disertasi ini membahas tentang kendali autonomous untuk quadrotor menggunakan Neural Network Direct Inverse Control NN-DIC . Tujuan dari penelitian ini adalah untuk menyelidiki kinerja Quadrotor menggunakan kontrol NN-DIC. Untuk mewujudkan penelitian ini, langkah pertama adalah untuk membangun sebuah platform Quadrotor. Karena ide dasar dari DIC adalah untuk menghilangkan efek dinamika plant dengan kendali inverse, maka langkah selanjutnya adalah membangun sebuah model NN-DIC menggunakan data penerbangan yang sebenarnya. Metode pelatihan backpropagation dipilih karena strukturnya sederhana namun mampu memberikan error yang kecil.Melalui beberapa simulasi, model kendali NN-DIC telah mampu menstabilkan quadrotor dengan performa yang sangat baik dalam mengikuti trajectory pada kondisi hover, perubahan altitude maupun manuver. Perfoma yang baik ini ditunjukan dengan nilai MSE yang kecil, yaitu 0.042 pada saat hover untuk kendali attitude, 0.340 pada saat perubahan altitude untuk kendali attitude-altitude dan terakhir nilai MSE sebesar 1.966 saat maneuver untuk kendali autonomous.

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The quadrotor is an Unmanned Aerial Vehicle UAV which is included in the category of rotary wing with four rotors located at its four corners. In order to move perfectly the quadrotor must be equipped with a control system capable of controlling and providing control signals of motor speed throughout the rotors.This dissertation discusses about autonomous control for quadrotor using Neural Network Direct Inverse Control NN DIC . The purpose of this study was to investigate Quadrotor performance using NN DIC controls. To realize this research, the first step is build a Quadrotor platform. Since the basic idea of DIC is to eliminate the dynamics effect of the plant with inverse control, the next step is build an NN DIC model using actual flight data. Backpropagation training method is chosen because the structure is simple but has a small error result.Some simulations have been done, the NN DIC control model has been able to stabilize the quadrotor with excellent performance in following trajectory under hover conditions, altitude changes and maneuvers. The excellent performance is indicated from a small MSE score of 0.042 during hover on attitude control, 0.340 with altitude change on attitude altitude control and MSE of 1.966 when maneuvered on autonomous control."

"This book brings together current knowledge on patterns and processes in the ecology of streams, lakes, and wetlands situated at more than 3000 m above sea level. The alpine headwaters of the large Asian rivers and Lake Titicaca are both well-known and iconic examples. High altitude waters include more than these systems. They are both numerous and cover many habitat types, organisms, and specializations. The book provides an overview of the variety of aquatic ecosystems and habitats, their environmental features, prominent species, and their functional adaptations to the harsh aquatic environmental conditions through to global diversity patterns along altitudinal gradients, community dynamics, species interactions and dispersal, trophic relations, and energy flows. High altitude waters are ideal systems to address a broad range of topical themes in ecology because patterns and processes are both diverse and singular. The book highlights how key concepts in ecology (e.g. the stress gradient hypothesis, the biodiversity, ecosystem functioning relationship) could find relevant study models in high altitude waters. The usual perception of pristine mountain waters is far from true, particularly in the case of high altitude waters at low latitudes where human population density is often high, and local communities live in intimate contact with, utilize, influence, and exploit these aquatic systems. Climate change effects, extinction risks of mountain populations due to vanishing glaciers, multiple human impacts, management, and conservation are also treated thoroughly. The book is richly illustrated with diagrams and numerous pictures of these poorly known systems and species."