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محمد نعمت اللہ ارشد گھمن
ادب انسانی زندگی کی عکاسی کرتا ہے۔ ہر انسان کی پہچان معاشرے سے ہوتی ہے اس لیے ادب اور معاشرہ باہم لازم و ملزوم ہیں۔اردو زبان کی تاریخ زیادہ قدیم نہیں ہے۔ تخلیق کارانسانی زندگی کے فہم کا دوسرا نام ہے اسی طرح نقاد تخلیق کاروں کی الجھی ہوئی گتھیاں سلجھاتا ہے۔وقت گزرنے کے ساتھ ساتھ اردو شاعری کے علاوہ اردو نثر کے دائرے بھی وسیع تر ہوتے جا رہے ہیں۔پاکستان بھرکی جامعات میں ایم فل اردو اسکالرز کے لیے سب سے بڑا مسئلہ ان متنوع موضوعات کے حوالے سے مواد کا حصول ہے اور ان کا بہت زیادہ وقت اسی میں ضائع ہوجاتا ہے۔اسی بات کو مدنظر رکھتے ہوئے اس کتاب کو پایہ تکمیل تک پہنچایا گیا ہے۔ ایم فل اردو کے مباحث پر اس سے پہلے کوئی کتاب میری نظر سے نہیں گزری اسی وجہ سے غالب امکان ہے کہ تحقیق کے طلبا کے لیے یہ کتاب آب حیات سے کم نہیں ہوگی۔
اس کتاب کی تیاری میں مجھے اپنے اساتذہ ڈاکٹر مشتاق عادل، ڈاکٹر محمد یوسف اعوان، ڈاکٹر محمد عامر اقبال، ڈاکٹر یاسمین کوثر،ڈاکٹر عبدالستار نیازی،ڈاکٹر قیصر آفتاب، ڈاکٹر عظیم اللہ جندران، میڈم ماریہ بلال کے علاوہ ہم جماعت صائمہ اختر کی بھرپور معاونت اور تعاون شامل حال رہا۔میں سب سے زیادہ اپنی شریک سفر کا ممنون ہوں جنہوں نے میرے تحقیقی اور تخلیقی سفر میں ہمیشہ آسانیاں پیدا کیں۔کوئی بھی بات یا تحریر حتمی نہیں ہوتی، اس کی بہتری کے دروازے ہمیشہ کھلے رہتے ہیں۔ قارئین کی آرا اور ناقدین کے مثبت تبصروں سے اس کتاب کا آئندہ ایڈیشن بہتر انداز میں سامنے آ سکے گا۔
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Pakistan’s involvement in the US war on terrorism was a tragic decision. No option was left for the ruling elite of Pakistan except to join the global war on terrorism and to take a U-turn from the support of Taliban’s regime in Afghanistan which was duly recognized by Pakistan’s government in 1996. It was expected by the policy-makers of the US that the alliance with Pakistan would provide extraordinary strength in combating the Al-Qaeda and other affiliated conglomerates in Afghanistan as well as in borderland area. However, after fifteen years of war, the alliance has enfeebled despite their mutual understanding regarding the objectives envisaged in the Strategic Partnership. The war on terrorism has now been escalated from Afghanistan to Pakistan and it has provided space to religious extremism, militancy, intolerance, ethnic division and sectarianism. There is no denial to the fact that religious extremism and terrorism are common threat and have damaged both the countries yet Pakistan has sacrificed more than the US in terms of human and material loss. Nevertheless, blame game and trust deficit is on the rise from both sides. This article focuses first on the joint ventures that the US and Pakistan mutually initiated to curb militant bloodbath in Afghanistan as well as in the border region. Secondly, it will explore factors responsible for increasing trust deficit between the partners. The study will not only provide deep understanding about the prevailing issues between Pakistan and the US but will also give true pictures to streamline the methodology for negotiating with each other in future.
Mobile Ad hoc Network (MANET) is a collection of mobile nodes that are connected wirelessly forming random topology through decentralised administration. In MANETs, multicasting is an important mechanism which can increase the network efficiency and reliability by sending multiple copies to a group of nodes in a single transmission without using several unicast transmissions. Multicast routing can be classified into tree based and mesh based multicasting. Mesh based protocols offer path redundancy for packets to move from senders to receivers. Thus, they offer greater resilience to link breakages than tree based protocols which offer only a single path from senders to receivers. Mesh based protocols have higher packet delivery ratios on the cost of higher overhead due to maintaining redundant paths. Receiver initiated mesh based multicast routing is the improved version having reliability and reduced overhead because the receivers only report the missing packets to the sender as compared to the sender initiated approach where each successful packet is reported to the sender. Receiver initiated mesh based multicast routing strongly relies on proper selection of a core node. The existing schemes suffer from various problems. First, the core selection process is not sophisticated that usually selects core in a manner that may decrease core lifetime and deteriorate network performance in the form of frequent core failures. Second, the existing schemes cause too much delay for core re-selection(s) process. The performance becomes worse in situations where frequent core failures occur and hence, the protocols may become unsuitable for delay sensitive applications. Finally, a malicious node may try to illegitimately become selected as core node (for some malicious purposes) or selfishly evade the core election process to save its resources. To solve the above issues, we propose an efficient, reliable and secure core assisted multicast Adhoc routing protocol (ERASCA) in which an efficient/stable core is selected based on parameters like battery capacity and location in a group. The selection of a stable core within the group minimizes the core failure scenario, thereby minimizes the flooding for finding another core and will decrease the overhead. To minimize delay and data collection process during core election after failures, we introduce the concept of mirror core in a group; hence, after the failure of the core the mirror core will take the responsibility as the main core without data collection process and delay and hence increases the overall reliability. To prevent the malicious/selfish nodes from illegitimately become core or evade the process of being a core node for saving resources, a iv malicious/selfish receiver is detected and discarded within the mesh by estimating their battery capacity. To collect the data for the estimation of battery capacity, we propose an overhearing based approach. To further protect the data from malicious/selfish receiver and to preserve the integrity of data, a packet authentication process is used. The proposed protocol is evaluated in NS-2 and compared against PUMA and MAODV which are the state of the art protocols in mesh based and tree based multicasting respectively. We compare these protocols under different metrics, such as mobility, number of senders, number of receivers, interface queue length and simulation area. According to the simulation results, ERASCA and ERASCA-MC attains higher packet delivery ratios and throughput than PUMA and MAODV, while incurring far less overhead, delay and energy consumption because of the efficient core election and with the introduction of the mirror core. To secure the core election process from malicious and selfish receivers, multiple simulations in NS-2 are performed in the presence and absence of detection technique. Simulation proves that in the presence of detection technique, core election will be more secured with improved performance in PDF, overhead, throughput and energy utilization.